THESIS on composite material

DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES1 CHAPTER-1 INTRODUCTION DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 2 INTRODUCTION 1.1- INTRODUCTION TO LIGHT WEIGHT AUTOMOBILE: Material competition in the automotive market has been traditionally intensive. Steel has been the dominant material used in building automobiles since the 1920s. What types of materials are likely to be winners in the 21st century? The automotive manufacturers‘ decisions on material‘s usage are complex and are determined by a number of factors. The increasing requirement to improve fuel economy triggered by concerns about global warming and energy usage has a significant influence on the choice of materials. For- Example The US government regulations mandate that the automotive companies. a)-Reduce vehicle exhaust emissions. b)-Improve occupant safety. c)-Reduce fuel consumptions. To meet this requirement, automotive manufacturers are making efforts to improve conventional engine efficiency, to develop new power trains such as hybrid systems and to reduce vehicle weight. Weight reduction is particularly important because average vehicle weight is expected to increase since the automobile industry will continue to market new models with increased luxury, convenience, performance, and safety as demanded by their customers. Safety features such as anti-block systems, air bags, and increasing safety body structure contribute to vehicle weight gain. Although, the car companies have responded to this by improving design and power train efficiency, these incremental improvements have not yet enabled a significant reduction in overall weight. If this is to be achieved, there will have to be a radical increase in the use of light weight materials. A rule of thumb is that 10% weight reduction approximately equals a 5.5% DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 3 improvement in fuel economy. An important fact is that weight reduction has a ripple effect on fuel efficiency. For example- weight reduction enables the manufacture to develop the same vehicle performance with a smaller engine, and such a smaller engine enables the use of a smaller transmission and a smaller fuel tank. With this ripple effect, it is estimated that 10% of vehicle weight reduction results in 8–10% of fuel economy improvement. In conclusion, automotive materials can have an important impact on the environment. In a vehicle, every pound of aluminum that replaces two pounds of steel can save 20 pounds of CO2 from being emitted. The use of lightweight materials can help reduce vehicle weight and improve fuel economy. The pressure for weight reduction has driven a gradual decrease in the amount of steel and cast iron used in vehicles and the corresponding increase in the amount of alternative materials, especially aluminium and plastics. VEHICLE WEIGHT TRENDS As size increases and more safety, performance and luxury features are added to vehicles, they continue to increase in weight. Since 1990, the weight of a typical family vehicle has steadily risen from 3140.5 pounds to 3357.5 pounds. A specific example of the increasing weight trend is the VW GTI. The original version of the GTI, introduced in 1976, weighed 1804 pounds, while the latest version weighs 2939 pounds. This increase represents a weight gain of approximately 40% over the 18-year life of the GTI. The original VW Golf is a substantially larger vehicle than the current Smart sub-compact, yet the Smart weighs slightly more than the Golf. Simultaneous to the weight increase trend, there has also been an increase use of aluminum castings, which has partially offset further weight increases. The typical family vehicle (i.e. cars, minivans, SUV‘s and light trucks) has increased in its aluminum casting content from 92.3 pounds in 1978 to 240 pounds in 2002. FUEL REDUCTION POTENTIAL ON REDUCED WEIGHT A vehicle that uses less fuel produces fewer greenhouse gas emissions. Over the average lifetime of a vehicle, every pound of aluminum that replaces two pounds of steel can save 20 pounds of CO2 from being emitted. Using aluminum to cut a vehicle's weight by 10% can boost its fuel DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 4 economy up to 8%, or as much as 2.5 extra miles per gallon. BMW studied vehicle weight reduction through the use of aluminum and reported fuel savings of between five and ten percent for each 10 percent reduction in weight. The Argonne National Laboratory also studied vehicle light weighting and reported a fuel savings of 6.6 percent for every 10 percent reduction in weight.TP 4PT A 6 to 8% fuel savings can be realized for every 10% reduction in weight from substituting aluminum for steel. Aluminum absorbs nearly twice as much energy as steel, and during a crash, aluminum folds like an accordion, letting the vehicle - not its passengers - absorb more of the crash forces. Lighter vehicles generally accelerate quicker and require shorter stopping distances than heavier vehicles. Aluminum castings have been critical to automakers meeting or exceeding federally mandated CAFÉ standards. It is estimated that lightweight castings have increased the CAFÉ fuel efficiency by 5% over the last ten years. 1.2- BACKGROUND: 1.2.1- ALUMINUM: According to Jefferson Lab, "Scientists suspected than an unknown metal existed in alum as early as 1787, but they did not have a way to extract it until 1825. Hans Christian Oersted, a Danish chemist, was the first to produce tiny amounts of aluminum. Two years later, Friedrich Wohler, a German chemist, developed a different way to obtain the metal. By 1845, he was able to produce samples large enough to determine some of aluminum's basic properties. Wohler‘s method was improved in 1854 by Henri Etienne Sainte-Claire Deville, a French chemist. Deville's process allowed for the commercial production of aluminum. As a result, the price of the metal dropped from around $1200 per kilogram in 1852 to around $40 per kilogram in 1859. Unfortunately, the metal remained too expensive to be widely used. Aluminium (or aluminum) is a chemical element in the boron group with symbol Al and atomic 13. It is a silvery white, soft, ductile metal. Aluminium is the third most abundant element (after oxygen and silicon), and the most abundant metal, in the Earth‘s crust. It makes up about 8% by weight of the Earth's solid surface. Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is found combined in over 270 different minerals. The chief ore of aluminium is bauxite. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 5 Aluminium is remarkable for the metal's low density and for its ability to resist corrosion due to the phenomenon of passivation. Structural components made from aluminium and its alloys are vital to the aerospace industry and are important in other areas of transportation and structural materials. The most useful compounds of aluminium, at least on a weight basis, are the oxides and sulfates. PHYSICAL Aluminium is a relatively soft, durable, lightweight, ductile and malleable metal with appearance ranging from silvery to dull gray, depending on the surface roughness. It is nonmagnetic and does not easily ignite. The yield strength of pure aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has one third in density and stiffness of steel. It is easily machined, cast, drawn and extruded. Aluminium is a good thermal and electrical conductor, having 59% the conductivity of copper, both thermal and electrical, while having only 30% of copper's density. Aluminium is capable of being a superconductor, with a superconducting critical temperature of 1.2 Kelvin and a critical magnetic field of about 100 gauss (10milliteslas). CHEMICAL Corrosion resistance can be excellent due to a thin surface layer of aluminium oxide that forms when the metal is exposed to air, effectively preventing further oxidation. The strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is also often greatly reduced by aqueous salts, particularly in the presence of dissimilar metals. Owing to its resistance to corrosion, aluminium is one of the few metals that retain silvery reflectance in finely powdered form, making it an important component of silver- colored paints. Aluminium mirror finish has the highest reflectance of any metal in the 200– 400 nm (UV) and the 3,000–10,000 nm (far IR) regions; in the 400–700 nm visible range it is slightly outperformed by tin and silver and in the 700–3000 (near IR) by silver, gold and copper. RECYCLING Aluminium is theoretically 100% recyclable without any loss of its natural qualities. According to the International Metal Stocks in Society report, the global per capita stock of aluminium in use in society (i.e. in cars, buildings, electronics etc.) is 80 kg. Much of this is in more-developed DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 6 countries (350–500 kg per capita) rather than less-developed countries (35 kg per capita). In Europe aluminium experiences high rates of recycling, ranging from 42% of beverage cans, 85% of construction materials and 95% of transport vehicles. Recycled aluminium is known as secondary aluminium, but maintains the same physical properties as primary aluminium. Secondary aluminium is produced in a wide range of formats and is employed in 80% of alloy injections. 1.2.2-ALUMINUM ALLOY: Aluminium alloys are alloys in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon and zinc. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. Alloys composed mostly of the two lightweight metals aluminium and magnesium have been very important in aerospace manufacturing since somewhat before 1940. Aluminium-magnesium alloys are both lighter than other aluminium alloys and much less flammable than alloys that contain a very high percentage of Selecting the right alloy for a given application entails considerations of its tensile strength, density, ductility, formability, workability, weld ability, and corrosion resistance. Aluminium alloys typically have an elastic modulus of about 70 GPa, which is about one-third of the elastic modulus of most kinds of steel and steel alloys. Therefore, for a given load, a component or unit made of an aluminium alloy will experience a greater elastic deformation than a steel part of the identical size and shape. Though there are aluminium alloys with somewhat- higher tensile strengths than the commonly used kinds of steel, simply replacing a steel part with an aluminium alloy might lead to problems. Aluminium alloys are widely used in automotive engines, particularly in cylinder blocks and crankcases due to the weight savings that are possible. Since aluminium alloys are susceptible to warping at elevated temperatures, the cooling system of such engines is critical. WROUGHT ALLOYS The International Alloy Designation System is the most widely accepted naming scheme for DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 7 wrought alloys. Each alloy is given a four-digit number, where the first digit indicates the major alloying elements.  1000 series are essentially pure aluminium with a minimum 99% aluminium content by weight and can be work hardened.  2000 series are alloyed with copper, can be precipitation hardened to strengths comparable to steel. Formerly referred to as duralumin, they were once the most common aerospace alloys, but were susceptible to stress corrosion cracking and are increasingly replaced by 7000 series in new designs.  3000 series are alloyed with manganese, and can be work hardened.  4000 series are alloyed with silicon. They are also known as sliming.  5000 series are alloyed with magnesium.  6000 series are alloyed with magnesium and silicon, are easy to machine, and can be precipitation hardened, but not to the high strengths that 2000 and 7000 can reach.  7000 series are alloyed with zinc, and can be precipitation hardened to the highest strengths of any aluminium alloy.  8000 series is a category mainly used for lithium alloys USES:  5000 series  Aluminium alloy 5005 is used in decorative and architectural applications that require an anodized finish.  Aluminium alloys 5052, 5251, and 5754 are very similar grades, only differing in the amount of magnesium. 5052 has 2.5% magnesium and is commonly used in the U.S.; 5251 has 2% magnesium and is commonly used in the UK; and 5754 has 3% magnesium and is commonly used in Europe. Due to their formability, corrosion resistance and weld ability these grades are commonly used in pressure vessels, tanks, fitting, boat hulls, and van bodies. Their salt water corrosion resistance is better than the 1200 grade and their strength is better than the 3003 grade.  Aluminium alloy 5083 is an aluminium alloy suitable for cryogenic applications down to design temperatures of −165 °C (−265 °F), since alloys of this type do not show DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 8 the transition phenomenon. This alloy is also common for the marine applications such as body materials for ships, underwater vehicles etc.  6000 series  6061-T6 is one of the most commonly used 6000 series aluminum alloys (see 6061 aluminium alloy)  6063 is an aluminium alloy, with magnesium and silicon as the alloying elements. The standard controlling its composition is maintained by The Aluminum Association. It has generally good mechanical properties and is heat treatable and wieldable. It is similar to the British aluminium alloy HE9.  6063 is mostly used in extruded shapes for architecture, particularly window frames, door frames, roofs, and sign frames. It is typically produced with very smooth surfaces fit for anodizing. 1.2.3- SILICON CARBIDE: Non-systematic, less-recognized, and often unverified syntheses of silicon carbide were reported early, J. J. Berzelius's reduction of potassium fluorosilicate by potassium (1810); Charles Mansuète Deseret‘s (1792–1863) passing an electric current through a carbon rod embedded in sand (1849); Robert Sydney Marsden's (1856–1919) dissolution of silica in molten silver in a graphite crucible (1881); Albert Colson's heating of silicon under a stream of ethylene (1882); and Paul Schuetzenberger's heating of a mixture of silicon and silica in a graphite crucible (1881).Nevertheless, wide-scale production is credited to Edward Goodrich Acheson in 1890. Acheson was attempting to prepare artificial diamonds when he heated a mixture of clay (aluminum silicate) and powdered coke (carbon) in an iron bowl. He called the blue crystals that Formed Carborundum, believing it to be a new compound of carbon and aluminum, similar to corundum. In 1893, Henri Moissan discovered the very rare naturally-occurring SiC mineral while examining rock samples found in the Canyon Diablo meteorite in Arizona. The mineral was named moissanite in his honor. Moissan also synthesized SiC by several routes, including: the dissolution of carbon in molten silicon; melting a mixture of calcium carbide and silica; and by reducing silica with carbon in an electric furnace. However, Moissan ascribed the original DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 9 discovery of SiC to Acheson in 1903. Because of the rarity of natural moissanite, most silicon carbide is synthetic. It is used as an abrasive, and more recently as a semiconductor and diamond stimulant of gem quality. The simplest manufacturing process is to combine silica sand and carbon in an Acheson graphite electric resistance furnace at a high temperature, between 1600 and 2500 °C. Fine SiO 2 particles in plant material (e.g. rice husks) can be converted to SiC by heating in the excess carbon from the organic material. The silica fume, which is a byproduct of producing silicon metal and ferrosilicon alloys, also can be converted to SiC by heating with graphite. TABLE 1.1 SILICON CARBIDE PROPERTIES Mechanical SI/Metric (Imperial) SI/Metric (Imperial) Density gm/cc (lb/ft 3 ) 3.1 (193.5) Porosity % (%) 0 (0) Color — black — Flexural Strength MPa (lb/in 2 x10 3 ) 550 (80) Elastic Modulus GPa (lb/in 2 x10 6 ) 410 (59.5) Shear Modulus GPa (lb/in 2 x10 6 ) — — Bulk Modulus GPa (lb/in 2 x10 6 ) — — Poisson‘s Ratio — 0.14 (0.14) Compressive Strength MPa (lb/in 2 x10 3 ) 3900 (566) Hardness Kg/mm 2 2800 — Fracture Toughness K IC MPa•m 1/2 4.6 — Maximum Use Temperature (no load) °C (°F) 1650 (3000) Thermal DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 10 Thermal Conductivity W/m•°K (BTU•in/ft 2 •hr•°F) 120 (830) Coefficient of Thermal Expansion 10 –6 /°C (10 –6 /°F) 4.0 (2.2) Specific Heat J/Kg•°K (Btu/lb•°F) 750 (0.18) Electrical Dielectric Strength ac-kv/mm (volts/mil) — semiconductor 1.2.4-COMPOSITES: Mankind has been aware composite materials since several hundred years before Christ and applied innovation to improve the quality of life. Although it is not clear has to how Man understood the fact that mud bricks made sturdier houses if lined with straw, he used them to make buildings that lasted. Ancient Pharaohs made their slaves use bricks with to straw to enhance the structural integrity of their buildings, some of which testify to wisdom of the dead civilization even today. Contemporary composites results from research and innovation from past few decades have progressed from glass fiber for automobile bodies to particulate composites for aerospace and a range other applications. A composite material is a material made up of two or more materials that are combined in a way that allows the materials to stay distinct and identifiable. The purpose of composites is to allow the new material to have strengths from both materials, often times covering the original materials' weaknesses. Composites are different from alloys because alloys are combined in such a way that it is impossible to tell one particle, element, or substance from the other. Some common composite materials include concrete, fiberglass, mud bricks, and natural composites such as rock and wood. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 11 1.2.5- CLASSIFICATION OF COMPOSITES: Composite materials are commonly classified at following two distinct levels:  The first level of classification is usually made with respect to the matrix constituent. 1.2.6- POLYMER MATRIX COMPOSITES (PMCS): Polymers make ideal materials as they can be processed easily, possess lightweight, and desirable mechanical properties. It follows, therefore, that high temperature resins are extensively used in aeronautical applications. Two main kinds of polymers are thermo sets and thermoplastics. Thermo sets have qualities such as a well-bonded three-dimensional molecular structure after curing. They decompose instead of melting on hardening. Merely changing the basic composition of the resin is enough to alter the conditions suitably for curing and determine its other characteristics. They can be retained in a partially cured condition too over prolonged periods of time, rendering Thermo sets very flexible. Thus, they are most suited as matrix bases for advanced conditions fiber reinforced composites. Thermoplastics have one- or two-dimensional molecular structure and they tend to at an elevated temperature and show exaggerated melting point. Another advantage is that the process of softening at elevated temperatures can reversed to regain its properties during cooling, facilitating applications of conventional compress techniques to mould the compounds. Resins reinforced with thermoplastics now comprised an emerging group of composites. The theme of most experiments in this area to improve the base properties of the resins and extract the greatest functional advantages from them in new avenues, including attempts to replace metals in die-casting processes. In crystalline thermoplastics, the reinforcement affects the morphology to a considerable extent, prompting the reinforcement to empower nucleation. Whenever crystalline or amorphous, these resins possess the facility to alter their creep over an extensive range of temperature. But this range includes the point at which the usage of resins is constrained, and the reinforcement in such systems can increase the failure load as well as creep resistance. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 12 Fig 1.1 kinds of thermoplastics 1.2.7-METAL MATRIX COMPOSITES (MMCS): Metal matrix composites, at present though generating a wide interest in research fraternity, are not as widely in use as their plastic counterparts. High strength, fracture toughness and stiffness are offered by metal matrices than those offered by their polymer counterparts. They can withstand elevated temperature in corrosive environment than polymer composites. Most metals and alloys could be used as matrices and they require reinforcement materials which need to be stable over a range of temperature and non-reactive too. However the guiding aspect for the choice depends essentially on the matrix material. Light metals form the matrix for temperature application and the reinforcements in addition to the aforementioned reasons are characterized by high moduli. Most metals and alloys make good matrices. However, practically, the choices for low temperature applications are not many. Only light metals are responsive, with their low density proving an advantage. Titanium, Aluminium and magnesium are the popular matrix metals currently in vogue, which are particularly useful for aircraft applications. If metallic matrix materials have to offer high strength, they require high modulus reinforcements. The strength-to- weight ratios of resulting composites can be higher than most alloys. The melting point, physical and mechanical properties of the composite at various temperatures determine the service temperature of composites. Most metals, ceramics and compounds can be used with matrices of low melting point alloys. The choice of reinforcements becomes more stunted with increase in the melting temperature of matrix materials. Thermoplastics Polyethylene Polystyrene Polyamides Nylons Polypropylene DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 13 ADVANTAGES OF MMCS  Higher strength-to-density ratios.  Higher stiffness-to-density ratios.  Better fatigue resistance.  Better elevated temperature properties. THE ADVANTAGES OF MMCS OVER POLYMER MATRIX COMPOSITES ARE:  Higher temperature capability.  Fire resistance.  Higher transverse stiffness and strength.  No moisture absorption.  Higher electrical and thermal conductivities.  Better radiation resistance. DISADVANTAGES OF MMCS: Some of the disadvantages of MMCs compared to polymer matrix composites are:  Higher cost of some material systems  Relatively immature technology  Complex fabrication methods for fiber-reinforced systems (except for casting)  Limited service experience. 1.2.8-CERAMIC MATRIX COMPOSITES (CMCS): Ceramics can be described as solid materials which exhibit very strong ionic bonding in general and in few cases covalent bonding. High melting points, good corrosion resistance, stability at elevated temperatures and high compressive strength, render ceramic-based matrix materials a favorite for applications requiring a structural material that doesn‘t give way at temperatures above 1500ºC. Naturally, ceramic matrices are the obvious choice for high temperature applications. High modulus of elasticity and low tensile strain, which most ceramics posses, have combined to cause the failure of attempts to add reinforcements to obtain strength improvement. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 14 A material is reinforcement to utilize the higher tensile strength of the fiber, to produce an increase in load bearing capacity of the matrix. Addition of high-strength fiber to a weaker ceramic has not always been successful and often the resultant composite has proved to be weaker. When ceramics have a higher thermal expansion coefficient than reinforcement materials, the resultant composite is unlikely to have a superior level of strength. In that case, the composite will develop strength within ceramic at the time of cooling resulting in micro cracks extending from fiber to fiber within the matrix. Micro cracking can result in a composite with tensile strength lower than that of the matrix. 1.2.9 - CARBON MATRIX COMPOSITES (CMCS): Carbon and graphite have a special place in composite materials options, both being highly superior, high temperature materials with strengths and rigidity that are not affected by temperature up to 2300ºC. This carbon-carbon composite is fabricated through compaction of carbon or multiple impregnations of porous frames with liquid carbonized precursors and subsequent pyrolization. They can also be manufactured through chemical vapour deposition of paralytic carbon. However, their capacity to retain their properties at room temperature as well as at temperature in the range of 2400ºC and their dimensional stability make them the oblivious choice in a garnet of applications related to aeronautics, military, industry and space. Components, that are exposed to higher temperature and on which the demands for high standard performance are many, are most likely to have carbon-carbon composites used in them. 1.2.10- GLASS MATRIX COMPOSITES (GMCS): In comparison to ceramics and even considered on their own merit, glass matrices are found to be more reinforcement-friendly. The various manufacturing methods of polymers can be used for glass matrices. Glasses are meant to improve upon performance of several applications. Glass matrix composite with high strength and modulus can be obtained and they can be maintained up to temperature of the order of 650ºC. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 15 Composites with glass matrices are considered superior in dimensions to polymer or metal system, due to the low thermal expansion behavior. This property allows fabrication of many components in intricate shapes and their tribological characters are considered very special. Since the elastic modulus of glass is far lower than of any prospective reinforcement materials, application of stress usually results in high elasticity modulus fiber that the tensile strength of the composite its considerably enhanced than that of the constituents, which is not case in ceramic matrices • The second level of classification refers to the reinforcement form: 1.2.11-REINFORCEMENTS: Reinforcements for the composites can be fibers, fabrics particles or whiskers. Fibers are essentially characterized by one very long axis with other two axes either often circular or near circular. Particles have no preferred orientation and so does their shape. Whiskers have a preferred shape but are small both in diameter and length as compared to fibers. Figure 1.4 shows types of reinforcements in composites. Reinforcing constituents in composites, as the word indicates, provide the strength that makes the composite what it is. But they also serve certain additional purposes of heat resistance or conduction, resistance to corrosion and provide rigidity. Reinforcement can be made to perform all or one of these functions as per the requirements. A reinforcement that embellishes the matrix strength must be stronger and stiffer than the matrix and capable of changing failure mechanism to the advantage of the composite. This means that the ductility should be minimum or even nil the composite must behave as brittle as possible. 1.2.12-FIBRE REINFORCED COMPOSITES: Fibers are the important class of reinforcements, as they satisfy the desired conditions and transfer strength to the matrix constituent influencing and enhancing their properties as desired. Glass fibers are the earliest known fibers used to reinforce materials. Ceramic and metal fibers were subsequently found out and put to extensive use, to render composites Stiffer more resistant to heat. Fibers fall short of ideal performance due to several factors. The performance of a fiber composite is judged by its length, shape, and orientation, composition of the fibers and the mechanical properties of the matrix. In very strong matrices, moduli and strengths have not been DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 16 observed. Application of the strength of the composites with such matrices and several orientations is also possible. Given the fact that the vast difference in length and effective dia. Fig-1.2 types of reinforcements of the fiber are assets to a fiber composite, it follows that greater strength in the fiber can be achieved by smaller diameters due to minimization or total elimination of surface of surface defects. After flat-thin filaments came into vogue, fibers rectangular cross sections have provided new options for applications in high strength structures. Owing to their shapes, these fibers provide perfect packing, while hollow fibers show better structural efficiency in composites that are desired for their stiffness and compressive strengths. In hollow fibers, the transverse compressive strength is lower than that of a solid fiber composite whenever the hollow portion is more than half the total fiber diameter. However, they are not easy to handle and fabricate. Reinforcements Fibers Filled Whiskers Flake Particulates Directionally Soeutectics lidified Particle filled Microspores Solid Hollow DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 17 1.2.13-TYPES OF FIBERS: Organic and inorganic fibers are used to reinforce composite materials. Almost all organic fibers have low density, flexibility, and elasticity. Inorganic fibers are of high modulus, high thermal stability and possess greater rigidity than organic fibers and notwithstanding the diverse advantages of organic fibers which render the composites in which they are used. Mainly, the following different types of fibers namely, glass fibers, silicon carbide fibers, high silica and quartz fibers, alumina fibers, metal fibers and wires, graphite fibers, boron fibers, aramid fibers and multiphase fibers are used. Among the glass fibers, it is again classified into E-glass, A- glass, R-glass etc. There is a greater marker and higher degree of commercial movement of organic fibers. The potential of fibers of graphite, silica carbide and boron are also exercising the scientific mind due to their applications in advanced composites. I. GLASS FIBERS: Over 95% of the fibers used in reinforced plastics are glass fibers, as they are inexpensive, easy to manufacture and possess high strength and stiffness with respect to the plastics with which they are reinforced. Their low density, resistance to chemicals, insulation capacity are other bonus characteristics, although the one major disadvantage in glass is that it is prone to break when subjected to high tensile stress for a long time. This property mitigates the effective strength of glass especially when glass is expected to sustain loads for many months or years continuously. Addition of chemicals to silica sand while making glass yields different types of glasses. II. METALS FIBERS: As reinforcement, metal fibers have many advantages. They are easily produced using several fabrication processes and are more ductile, apart from being not too sensitive to surface damage and possess high strengths and temperature resistance. However, their weight and the tendency to react each other through alloying mechanisms are major disadvantages. Metal wires, of the continuous version; also reinforce plastics like polyethylene and epoxy temperature and the resultant steep variations of thermal expansion coefficient with the resins are a discouragement that limits their application. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 18 III. ALUMINA FIBERS: Alumina aluminium oxide fibers, basically developed for use in metal matrices are considered a potential resin-matrix composite reinforcement. It offers good compressive strength rather than tensile strength. Its important property is its high melting point of about 2000ºC and the composite can be successfully used at temperature up to about 1000ºC. Magnesium and aluminum matrices frequently use alumina fiber reinforced composites as they do not damage the fiber even in the liquid state. IV. BORON FIBERS: They are basically composites, in which boron is coated on a substance which forms the substrate, usually made of tungsten. Boron-tungsten fibers are obtained by allowing hot tungsten filament through a mixture of gases. The tungsten however remains constant in its thickness. Properties of boron fibers generally change with the diameter, because of the changing ratio of boron to tungsten and the surface defects that change according to size. Boron coated carbons are much cheaper to make than boron tungsten fiber. But is low modulus of elasticity often works against it. V. SILICON CARBIDE FIBERS: Silicon carbide can be coated over a few metals and their room temperature tensile strengths and tensile moduli are like those boron-tungsten. The advantages of silicon carbide-tungsten are several and are more desirable than uncoated boron tungsten fibers. However, Silicon carbide- tungsten fibers are dense compared to boron-tungsten fibers of the same diameters. They are prone to surface damage and need careful, delicate handling, especially during fabrication of the composite. Further, above 930ºC weakening reactions occur between tungsten and silicon carbide, making it different to maintain balance in high-temperature matrix formations. Silicon carbide on carbon substrates have several advantages, viz. no reaction at high temperature, being lighter than silicon carbide tungsten and possessing tensile strengths and modulus that is are often better than those of silicon carbide-tungsten and boron fibers. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 19 VI. QUARTZ AND SILICA FIBERS: The glass-types typically contain about 50 to 70% silica. Quartz is even more pure, and quartz fibers are made from natural quartz crystals that contain 99.9% silica, possessing nearly all the properties of pure solid quartz. They are highly elastic and can be stretched to 1% of their length before break point. Both silica and quartz are not affected by acid attacks and are resistant to moisture. Owing to their thermal properties, silica and quartz are the natural choice as fibers in several applications. They have good insulting properties and do not melt at temperature up to 1600ºC. In addition, they have a low thermal expansion coefficient which makes them withstand high temperatures. VII. GRAPHITE FIBERS: While use of the term carbon for graphite is permissible, there is one basic difference between the two. Element analysis of poly-acryl-nitride (PAN) base carbon fibers show that they consist of 91 to 94% carbon. But graphite fibers are over 99% carbon. The difference arises from the fact that the fibers are made at different temperatures PAN-based carbon cloth or fiber is produced at about 1320ºC, while graphite fibers and cloth are graphitized at 1950 to 3000ºC. Cheaper pitch base fiber are now being developed, with greater performance potential and there are possibilities of the increased use of graphite fibers. VIII. MULTIPHASE FIBERS: Spool able filaments made by chemical vapors deposition processes are usually the multiphase variety and they usually comprise materials like boron, silicon and their carbides formed on surface of a very fine filament substrate like carbon or tungsten. They are usually good for high temperature applications, due to their reduced reaction with higher melting temperature of metals than graphite and other metallic fibers. Boron filaments are sought after for structural and intermediate-temperature composites. A poly-phase fiber is a core-sheath fiber consisting of a poly-crystalline core. 1.2.14-LAMINAR COMPOSITES: Laminar composites are found in as many combinations as the number of materials. They can be described as materials comprising of layers of materials bonded together. These may be of DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 20 several layers of two or more metal materials occurring alternately or in a determined order more than once, and in as many numbers as required for a specific purpose. Clad and sandwich laminates have many areas as it ought to be, although they are known to follow the rule of mixtures from the modulus and strength point of view. Other intrinsic values pertaining to metal- matrix, metal-reinforced composites are also fairly well known. 1.2.15-FLAKE COMPOSITES: Flakes are often used in place of fibers as can be densely packed. Metal flakes that are in close contact with each other in polymer matrices can conduct electricity or heat, while mica flakes and glass can resist both. Flakes are not expensive to produce and usually cost less than fibers. Flakes have various advantages over fibers in structural applications. Parallel flakes filled composites provide uniform mechanical properties in the same plane as the flakes. While angle- plying is difficult in continuous fibers which need to approach isotropic properties, it is not so in flakes. Flake composites have a higher theoretical modulus of elasticity than fiber reinforced composites. They are relatively cheaper to produce and be handled in small quantities. 1.2.16-FILLED COMPOSITES: Filled composites result from addition of filer materials to plastic matrices to replace a portion of the matrix, enhance or change the properties of the composites. The fillers also enhance strength and reduce weight. Another type of filled composite is the product of structure infiltrated with a second-phase filler material. The skeleton could be a group of cells, honeycomb structures, like a network of open pores. The infiltrated could also be independent of the matrix and yet bind the components like powders or fibers, or they could just be used to fill voids. Fillers produced from powders are also considered as particulate composite. 1.2.17-PARTICULATE REINFORCED COMPOSITES: Microstructures of metal and ceramics composites, which show particles of one phase strewn in the other, are known as particle reinforced composites. Square, triangular and round shapes of reinforcement are known, but the dimensions of all their sides are observed to be more or less equal. The size and volume concentration of the dispersion distinguishes it from dispersion hardened materials. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 21 In particulate composites, the particles strengthen the system by the hydrostatic coercion of fillers in matrices and by their hardness relative to the matrix. Three-dimensional reinforcement in composites offers isotropic properties, because of the three systematical orthogonal planes. Since it is not homogeneous, the material properties acquire sensitivity to the constituent properties, as well as the interfacial properties and geometric shapes of the array. The composite‘s strength usually depends on the diameter of the particles, the inter-particle spacing, and the volume fraction of the reinforcement. The matrix properties influence the behavior of particulate composite too. 1.2.18-COMPARISON WITH METALS: Requirements governing the choice of materials apply to both metals and reinforced plastics. It is, therefore, imperative to briefly compare main characteristics of the two.  Composites offer significant weight saving over existing metals. Composites can provide structures that are 25-45% lighter than the conventional aluminium structures designed to meet the same functional requirements. This is due to the lower density of the composites. Depending on material form, composite densities range from 1260 to 1820 kg/in 3 (0.045 to 0.065 lb/in 3 ) as compared to 2800 kg/in 3 (0.10 lb/in 3 ) for aluminium. Some applications may require thicker composite sections to meet strength/stiffness requirements, however, weight savings will still result.  Unidirectional fiber composites have specific tensile strength (ratio of material strength to density) about 4 to 6 times greater than that of steel and aluminium.  Unidirectional composites have specific -modulus (ratio of the material stiffness to density) about 3 to 5 times greater than that of steel and aluminium.  Fatigue endurance limit of composites may approach 60% of their ultimate tensile strength. For steel and aluminium, this value is considerably lower.  Fiber composites are more versatile than metals, and can be tailored to meet performance needs and complex design requirements such as aero-elastic loading on the wings and the vertical & the horizontal stabilizers of aircraft. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 22  Fiber reinforced composites can be designed with excellent structural damping features. As such, they are less noisy and provide lower vibration transmission than metals.  High corrosion resistance of fiber composites contributes to reduce life- cycle cost.  Composites offer lower manufacturing cost principally by reducing significantly the number of detailed parts and expensive technical joints required to form large metal structural components. In other words, composite parts can eliminate joints/fasteners thereby providing parts simplification and integrated design.  Long term service experience of composite material environment and durability behavior is limited in comparison with metals. 1.2.19-ADVANTAGES AND DISADVANTAGE OF COMPOSITES: ADVANTAGES The advantages exhibited by composite materials, which are of significant use in aerospace and automobile industry are as follows: • High resistance to fatigue and corrosion degradation. • High ‗strength or stiffness to weight‘ ratio. As enumerated above, weight savings are significant ranging from 25-45% of the weight of conventional metallic designs. • Due to greater reliability, there are fewer inspections and structural repairs. • Directional tailoring capabilities to meet the design requirements. The fiber pattern can be laid in a manner that will tailor the structure to efficiently sustain the applied loads. • Fiber to fiber redundant load path. • Improved dent resistance is normally achieved. Composite panels do not sustain damage as easily as thin gage sheet metals. • It is easier to achieve smooth aerodynamic profiles for drag reduction. Complex double- curvature parts with a smooth surface finish can be made in one manufacturing operation. • Composites offer improved torsion stiffness. This implies high whirling speeds, reduced number of intermediate bearings and supporting structural elements. The overall part count and manufacturing & assembly costs are thus reduced. • High resistance to impact damage. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 23 • Thermoplastics have rapid process cycles, making them attractive for high volume commercial applications that traditionally have been the domain of sheet metals. Moreover, thermoplastics can also be reformed. • Like metals, thermoplastics have indefinite shelf life. • Composites are dimensionally stable i.e. they have low thermal conductivity and low coefficient of thermal expansion. Composite materials can be tailored to comply with a broad range of thermal expansion design requirements and to minimize thermal stresses. • Manufacture and assembly are simplified because of part integration (joint/fastener reduction) thereby reducing cost. • The improved weather ability of composites in a marine environment as well as their corrosion resistance and durability reduce the down time for maintenance. • Close tolerances can be achieved without machining. • Material is reduced because composite parts and structures are frequently built to shape rather than machined to the required configuration, as is common with metals. • Excellent heat sink properties of composites, especially Carbon-Carbon, combined with their lightweight have extended their use for aircraft brakes. • Improved friction and wear properties. • The ability to tailor the basic material properties of a Laminate has allowed new approaches to the design of aero elastic flight structures. DISADVANTAGE Some of the associated disadvantages of advanced composites are as follows:  High cost of raw materials and fabrication.  Composites are more brittle than wrought metals and thus are more easily damaged.  Transverse properties may be weak.  Matrix is weak, therefore, low toughness.  Reuse and disposal may be difficult.  Difficult to attach.  Repair introduces new problems, for the following reasons:  Materials require refrigerated transport and storage and have limited shelf life.  Hot curing is necessary in many cases requiring special tooling. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 24  Hot or cold curing takes time.  Analysis is difficult.  Matrix is subject to environmental degradation. 1.2.20- MATRIX MATERIALS: Although it is undoubtedly true that the high strength of composites is largely due to the fiber reinforcement, the importance of matrix material cannot be underestimated as it provides support for the fibers and assists the fibers in carrying the loads. It also provides stability to the composite material. Resin matrix system acts as a binding agent in a structural component in which the fibers are embedded. When too much resin is used, the part is classified as resin rich. On the other hand if there is too little resin, the part is called resin starved. A resin rich part is more susceptible to cracking due to lack of fiber support, whereas a resin starved part is weaker because of void areas and the fact that fibers are not held together and they are not well supported. 1.2.21-FUNCTIONS OF A MATRIX: In a composite material, the matrix material serves the following functions:  Holds the fibers together.  Protects the fibers from environment.  Distributes the loads evenly between fibers so that all fibers are subjected to the same amount of strain.  Enhances transverse properties of a laminate.  Improves impact and fracture resistance of a component.  Helps to avoid propagation of crack growth through the fibers by providing alternate failure path along the interface between the fibers and the matrix.  Carry interlaminar shear. The matrix plays a minor role in the tensile load-carrying capacity of a composite structure. However, selection of a matrix has a major influence on the interlaminar shear as well as in- plane shear properties of the composite material. The interlaminar shear strength is an important DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 25 design consideration for structures under bending loads, whereas the in-plane shear strength is important under torsion loads. The matrix provides lateral support against the possibility of fiber buckling under compression loading, thus influencing to some extent the compressive strength of the composite material. The interaction between fibers and matrix is also important in designing damage tolerant structures. Finally, the process ability and defects in a composite material depend strongly on the physical and thermal characteristics, such as viscosity, melting point, and curing temperature of the matrix. 1.2.22-PROPERTIES OF A MATRIX: The needs or desired properties of the matrix which are important for a composite structure are as follows:  Reduced moisture absorption.  Low shrinkage.  Low coefficient of thermal expansion.  Good flow characteristics so that it penetrates the fiber bundles completely and eliminates voids during the compacting/curing process.  Reasonable strength, modulus and elongation (elongation should be greater than fiber).  Must be elastic to transfer load to fibers.  Strength at elevated temperature (depending on application).  Low temperature capability (depending on application).  Excellent chemical resistance (depending on application).  Should be easily process able into the final composite shape.  Dimensional stability (maintains its shape). 1.2.23-FACTORS CONSIDERED FOR SELECTION OF MATRIX: In selecting matrix material, following factors may be taken into consideration: • The matrix must have a mechanical strength commensurate with that of the reinforcement i.e. both should be compatible. Thus, if a high strength fiber is used as the reinforcement, there is no point using a low strength matrix, which will not transmit stresses efficiently to the reinforcement. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 26 • The matrix must stand up to the service conditions, viz., temperature, humidity, exposure to ultra-violet environment, exposure to chemic3l atmosphere, abrasion by dust particles, etc. • The matrix must be easy to use in the selected fabrication process. • Smoke requirements. Life expectancy. • The resultant composite should be cost effective. 1.2.24- GENERAL TYPES OF MATRIX MATERIALS: In general, following general following types of matrix materials are available: • Thermosetting Matrix Materials. • Thermoplastic Matrix Materials. • Carbon Matrix Materials. • Metals Matrix Materials. • Ceramics Matrix Materials. • Glass Matrix Materials. 1.2.25- APPLICATION OF METAL MATRIX COMPOSITES: Application of metal matrix composites in aerospace, transportation, construction, marine goods, sporting goods, and more recently infrastructure, with construction and transportation being the largest. In general, high-performance but more costly continuous-carbon-fiber composites are used where high strength and stiffness along with light weight are required. I-AUTOMOTIVE APPLICATION: Example:-  PISTONS AND CYLINDER LINERS Aluminum engine blocks typically require cast iron cylinder liners due to poor wear characteristics of aluminum. Porsche is using MMCs for cylinder liners by integrating porous silicon perform into the cast aluminum block, and Honda uses a similar method incorporating DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 27 alumina and carbon fibers in the bores of die cast aluminum. These practices improve wear characteristics and cooling efficiency over cast iron liners. Providing superior wear resistance, improved cold start emissions, and reduced weight .Aluminum-based composite liners can be cast in place using conventional casting techniques, including sand, permanent mold, die casting, and Centrifugal casting.  CONNECTING RODS With the advent of nanostructure materials, new materials have been developed with exceptional properties exceeding those expected for monolithic alloys or composites containing micron-scale reinforcements. For example, carbon nanotubes have ultrahigh strength and modulus; when included in a matrix, they could impart significant property improvements to the resulting nano- Fig-1.3 Partial short fiber reinforced light metal diesel pistons composite. In another example, incorporating only 10 vol% of 50-nm alumina (Al2O3) particles to an aluminum alloy matrix using the powder metallurgy process increased yield strength to 515 MPa. This is 15 times stronger than the base alloy, six times stronger than the base alloy DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 28 containing 46 vol% of 29-mm Al2O3, and over 1.5 times stronger than AISI 304 stainless steel. Research is in progress at UWM to cast aluminum-base nano-composites with possible strengths on the order of 0.5 to 1 GPa. However, some processing problems need to be resolved, and challenges of scaling up the technology need to be overcome. For components requiring high strength, such as connecting rods, cast aluminum-matrix nano-composites may be ideal to produce near-net-shape components to replace steel, forged aluminum, and titanium components, while reducing reciprocating mass.  SUSPENSION Many automakers started to use aluminum and light gage steel for suspension components to reduce unsprung weight and improve vehicle dynamics, but many components are still made of cast iron. Components such as control arms or wheel hubs made of strong silicon carbide (SiC) reinforced aluminum or aluminum nano-composites can further improve aluminum alloy designs by improving strength characteristics similar to cast iron, while using less material than similar aluminum arms. Self-lubricating graphite-reinforced aluminum bushings can also be incorporated into control-arm castings to allow for components that do not require service and will last the life of the vehicle.  BRAKES Automotive disk brakes and brake calipers, typically made of cast iron, are an area where significant weight reduction can be realized. SiC-reinforced aluminum brake rotors are incorporated in vehicles such as the Lotus Elise, Chrysler Prowler, General Motors EV1, Volkswagen Lupo 3L, and the Toyota RAV4-EV.Widespread use of aluminum composite brake rotors requires their costs to come down and improved machinability. UWM developed Aluminum-silicon carbide-graphite composites, aluminum alumina- graphite, and hypereutectic aluminum-silicon graphite alloys with reduced silicon carbide to help overcome cost and machinability barriers. Aluminum-fly ash Composites developed at UWM has been explored to make prototype brake rotors in Australia. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 29 Fig-1.4 Vented passenger car brake disk of particle reinforced aluminum II-AIRCRAFT AND AEROSPACE APLICATIONS: In military aircraft, low weight is ―king‖ for performance and payload reasons, and composites often approach 20 to 40 percent of the airframe weight. For decades, helicopters have incorporated glass fiber–reinforced rotor blades for improved fatigue resistance, and in recent years helicopter airframes have been built largely of carbon-fiber composites. Military aircraft applications, the first to use high performance continuous-carbon-fiber composites, drove the development of much of the technology now being used by other industries. Both small and large commercial aircraft rely on composites to decrease weight and increase fuel performance, the most striking example being the 50 percent composite airframe for the new Boeing 787 All future Airbus and Boeing aircraft will use large amounts of high-performance composites. Composites are also used extensively in both weight-critical reusable and expendable launch vehicles and satellite structures. Weight savings due to the use of composite materials in aerospace applications generally range from 15 to 25 percent. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 30 Fig. 1.5 Boeing 787 dream liner commercial airplane III- WIND TURBINES APLICATIONS: Wind power is the world‘s fastest-growing energy source. The blades for large wind turbines are normally made of composites to improve electrical energy generation efficiency. These blades can be as long as 120 ft (37 m) and weigh up to 11,500 lb (5200 kg). In 2007, nearly 50,000 blades for 17,000 turbines were delivered, representing roughly 400 million pounds. IV-MARINE INDUSTRY APPLICATIONS: Corrosion is a major headache and expense for the marine industry. Composites help minimize these problems, primarily because they do not corrode like metals or rot like wood and more weight reduction. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 31 Fig. 1.6 Wind turbines 1.2.26 –NANO-COMPOSITES: A nano-composite is a multiphase solid material where one of the phases has one, two or three dimensions of less than 100 nanometers (nm), or structures having nano-scale repeat distances between the different phases that make up the material. In the broadest sense this definition can include porous media, colloids, gels and copolymers, but is more usually taken to mean the solid combination of a bulk matrix and nano-dimensional phase(s) differing in properties due to dissimilarities in structure and chemistry. The mechanical, electrical, thermal, optical, DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 32 electrochemical, catalytic properties of the nano-composite will differ markedly from that of the component materials. Size limits for these effects have been proposed, <5 nm for catalytic activity, <20 nm for making a hard magnetic material soft, <50 nm for refractive index changes, and <100 nm for achieving superparamagnetism, mechanical strengthening or restricting matrix dislocation movement. Nano-composites are found in nature, for example in the structure of the abalone shell and bone. The use of nano particle-rich materials long predates the understanding of the physical and chemical nature of these materials. In mechanical terms, nano-composites differ from conventional composite materials due to the exceptionally high surface to volume ratio of the reinforcing phase. The area of the interface between the matrix and reinforcement phase(s) is typically an order of magnitude greater than for conventional composite materials. The matrix material properties are significantly affected in the vicinity of the reinforcement. Polymer nano-composites, properties related to local chemistry, degree of thermo set cure, polymer chain mobility, and polymer chain conformation, degree of polymer chain ordering or crystalline can all vary significantly and continuously from the interface with the reinforcement into the bulk of the matrix. 1.2.27-TYPES OF NANOCOMPOSITES: I) CERAMIC MATRIX NANOCOMPOSITES (CMNC) In this group of composites the main part of the volume is occupied by a ceramic, i.e. a chemical compound from the group of oxides, nitrides, borides, silicates etc. In most cases, ceramic-matrix nano-composites encompass a metal as the second component. Ideally both components, the metallic one and the ceramic one, are finely dispersed in each other in order to elicit the particular nanoscopic properties. Nano-composites from these combinations were demonstrated in improving their optical, electrical and magnetic properties as well as tribological, corrosion- resistance and other protective properties. II) METAL MATRIX NANOCOMPOSITES (MMNC) Metal matrix nano-composites (MMNC) refer to materials consisting of a ductile metal or alloy DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 33 matrix in which some nano sized reinforcement material is implanted. These materials combine metal and ceramic features, i.e., ductility and toughness with high strength and modulus. Thus, metal matrix nano-composites are suitable for production of materials with high strength in shear/compression processes and high service temperature capabilities. They show an extraordinary potential for application in many areas, such as aerospace, automotive industries. III) POLYMER MATRIX NANOCOMPOSITES (PMNC) In the simplest case, appropriately adding nano-particulates to a polymer matrix can enhance its performance, often in very dramatic degree, by simply capitalizing on the nature and properties of the nanoscale filler (these materials are better described by the term nanofilled polymer composites). This strategy is particularly effective in yielding high performance composites, when good dispersion of the filler is achieved and the properties of the nanoscale filler are substantially different or better than those of the matrix, for example, reinforcing a polymer matrix by much stiffer nanoparticles of ceramics, clays, or carbon nanotubes. 1.2.28-ADVANTAGES OF NANOCOMPOSITES: Nanocomposite materials have emerged as suitable alternatives to overcome limitations of micro-composites and monolithic, while posing preparation challenges related to the control of elemental composition and stoichiometry in the nanocluster phase. The following are the advantages of nanocomposites over conventional materials: 1. Greater tensile and flexural strength as compared to matrix material. 2. Reduced weight for the same performance. 3. Increased dimensional stability. 4. High modulus of elasticity and wear resistance. 5. High thermal stability. 6. Improved gas barrier properties for the same film thickness. 7. Flame retardant properties. 8. High temperature creep resistance. 9. Improved specific strength and stiffness. 10. Improved fracture toughness and thermal shock resistance. 11. Higher electrical conductivity. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 34 12. Higher chemical resistance. 1.2.29-APPLICATIONS OF NANOCOMPOSITES: Nanocomposites are finding applications in the following fields: Aerospace, defense, automobiles, medicine, electronics, materials, marine, industrial and construction markets etc. The other applications are: 1. Thin-film capacitors for computer chips. 2. Solid polymer electrolytes for batteries. 3. Automotive engine parts and fuel tanks. 4. Impellers and blades. 5. Oxygen and gas barriers. 6. Food packaging. 7. Drug delivery systems. 8. Anti-corrosion barrier coatings. 9. UV protection gels. 10. Lubricants and scratch free paints. 11. New fire retardant materials. 12. New scratch/abrasion resistant materials. 13. Superior strength fibers and films. 1.3 –PROBLEM STATEMENT: In the automobile industry weight reduction is most important because average vehicle weight is increased because in market continue new models comes with increased luxury, convenience, performance, and safety as demanded by their customers. Safety features such as anti-block systems, air bags, and increasing safety body structure. Hence if we used steel and cast iron for manufacturing automobile than weight of the automobile more to more increased. If weight increased than some problem induced such that- 1. Fuel consumptions increased. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 35 2. Global warming increased due to more pollution. 3. If weight increased than size of engine also increased. 4. If more weight than ride and handling of automobile is difficult. 5. Used Steel absorbs less energy as compare to Aluminum. The main problem is if used Al-Sic composites (macro particle> 100nm) for light weight vehicle than toughness of component decrease due to brittleness increase. Hence ability of shock absorption is decrease. That is a big problem for a vehicle. 1.4- OBJECTIVE: The objective of this thesis is to study the metal matrix composites and nano composites which are useful for light weight automobiles. And increasing the nano-sized Sic particles content helps to strengthen the composites, while the ductility is retained at place of macro SiC particle (>100nm). And make one part of automobile of Al-alloy, 10% SiC composites, 1% nano composites, and 2% nano composites and compare its properties like wear rate, hardness, tensile strength and compressive strength which is useful for replace existing material steel in automobiles sector. It types we can reduce the weight of automobiles. Hence reduce the fuel consumption and pollution in environment. 1.5- LAYOUT OF THIS THESIS:  Chapter 1 is ―Introduction‖ which provides a basic introduction to the light weight automobiles.  Chapter 2 is ―Literature Review‖ which provides a summary of the previous work done in metal matrix composites and light weight automobiles.  Chapter 3 is ―Experimental work‖ which gives an insight into the experiment adopted in this thesis.  Chapter 4 is ―Results & Discussions‖ which contains the important results of study.  Chapter 5 ―conclusions‖.  ―References‖ shows various references used in this thesis. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 36 CHAPTER-2 LITERATURE REVIEW DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 37 LITERATURE REVIEW 1. Rick Borns et.al.(2005) developed some automotive part of aluminum alloy like chassis and suspension, Knuckles. In Many vehicle chassis and suspension components are constructed of aluminum alloys, due to the metals relatively high strength-to-weight ratio and inherent corrosion resistance and it found that Increased use of aluminum in chassis and suspension systems reduces the overall weight of the vehicle, improves fuel efficiency and emissions performance while also improving ride and handling through reduced un-sprung mass and it see that in a vehicle, every pound of aluminum that replaces two pounds of steel can save 20 pounds of CO2 from being emitted. A 6 to 8% fuel savings can be realized for every 10% reduction in weight from substituting aluminum for steel. Aluminum absorbs nearly twice as much energy as steel. 2. Anthony Macke et.al.(2012) try to developed some automotive part of aluminum alloy composite at the ―Center for Composite Materials and Center for Advanced Materials Manufacture University of Wisconsin–Milwaukee‖ .and it found that these materials can be tailored to be lightweight and with various other properties including: • High specific strength and specific stiffness. • High hardness and wear resistance • Low coefficients of friction and thermal expansion. • High thermal conductivity • High energy absorption and a damping Capacity. And it make some parts Pistons and cylinder, Connecting rods, Suspension etc. and it conclude that the auto industry can customize high-strength, wear-resistant, and self-lubricating lightweight MMCs for specific applications to make significant weight reductions and improve fuel efficiency. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 38 3. Manoj Singla et.al.(2009) take Aluminium (98.41% C.P) and SiC (320-grit) has been chosen as matrix and reinforcement material respectively. Experiments have been conducted by varying weight fraction of SiC (5%, 10%, 15%, 20%, 25%, and 30%), while keeping all other parameters constant. The results indicated that the ‗developed method‘ is quite successful to obtain uniform dispersion of reinforcement in the matrix. An increasing trend of hardness and impact strength with increase in weight percentage of SiC has been observed. The best results (maximum hardness 45.5 BHN & maximum impact strength of 36 N-m). The results as indicated in Figures 5 and 6 show the increasing trend of hardness and impact strength with increase in weight percentage of SiC up to 25% weight fraction. Beyond this weight fraction the hardness trend started decreasing as SiC particles interact with each other leading to clustering of particles and consequently settling down. Eventually the density of SiC particles in the melt started decreasing thereby lowering the hardness. 4. S. DAS (2004) developed few prototype automobile components of aluminum matrix composites such as brake drums/discs and cylinder blocks for four-wheeler as well as for two wheelers. The test results show that the braking efficiency of AMC-brake drum is around 20% higher than that of the cast iron brake drum; while the weight reduction is around 60%.Additionally, the temperature rise in AMC-brake drum (97°C) is considerably less as compared to that of the cast iron (147°C) brake drum. The report from Vehicle Factory, Jabalpur stated that the brake drums worked satisfactorily without any difficulty. This work was sponsored by DRDO. 5. G. B. Veeresh Kumar et.al. (2011) try to decrease wear of aluminum by adding Si-C. Metal Matrix Composites are being increasingly used in aerospace and automobile industries owing to their enhanced properties such as elastic modulus, hardness, tensile strength at room and elevated temperatures, wear resistance combined with significant weight savings over un reinforced alloys and At any constant load, wear rate decreases with increase in addition of SiCp and improves the load bearing properties of Al-alloy during sliding. Increase in the addition of SiC restricts the flow or deformation of the matrix material with respect to load and increase in the density of the DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 39 composites compared to the base metal hence it concluded that the Al-MMCs will have better wear resistance than the unreinforced alloys. 6. G. G. Sozhamannan1 et.al.(2011) sea that The Ultimate strength of metal matrix composite de-creases with increasing holding time. It is revealed that holding time influences the viscosity of liquid metal, particles distribution and also induces some chemical reaction between matrix and reinforcement. Hence the hardness values increases more or less linearly with increasing of processing temperatures from 750°C to 800°C at 20 minutes holding time. 7. Yong Yang et.al. (2004) studied of costing and found that in costing extremely difficult to Disperse nano-sized ceramic particles uniformly in molten metal. But if we used Al-based nano- composites with nano-sized SiC were fabricated by an ultrasonic-assisted casting method. The microstructure and mechanical properties were studied. The nano-sized SiC particles are dispersed well in the matrix and the yield strength of A356 alloy was improved more than 50% with only 2.0 wt. % of nano-sized SC particles. Partial oxidation of SiC nanoparticles resulted in the formation of SiO2 in the matrix. The study suggests that strong ultrasonic nonlinear effects could efficiently disperse nanoparticles (less than 100 nm) into alloy melts while possibly enhancing their wet ability, thus making the production of as-cast high performance lightweight MMNCs feasible. 8. Ya-Cheng Lin et.al. (2012) developed an effective method for bonding of silicon carbide (SiC) ceramic to 5083 Aluminum metal-alloys. This method employed the concept of high- temperature rapid heterogeneous combustion reaction to joint dissimilar materials. An exothermic mixture of titanium and carbon powders (molar ratio 1:0.4) was utilized as a joining reactive layer. The concept of using a novel high temperature rapid reactive welding technique for joining dissimilar materials, i.e. SiC ceramic to Al-alloy 5083, has been verified. The experimental approach, based on the use of a rapid high temperature heterogeneous combustion pressing process, has been validated. Two compositions (pure Ti and a mixture of Ti/C powders) were used to initiate the combustion joining and both demonstrated feasible routes to bond dissimilar materials. The scaled-up welding system is applied for the first time to join dissimilar DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 40 material with application of external loads on the sample stack and a more uniform nano-scale interface is produced. 9. Jae-Chul Lee et.al. (1999) studied and found that in general, a frequent problem encountered in fabricating Al alloy based composites reinforced with various carbides such as SiC, B4C, TiC, including Graphite, etc. can be the formation of Al4C3 at the carbide matrix interface as a result of the interfacial reaction between the Al matrix and carbides. Al4C3 are known to be very brittle and unstable and very sensitive to corrosive environments resulting in the degradation of mechanical properties of composites. Therefore formation of Al4C3 during composite fabrication has to be either avoided or minimized. Hence for avoided this problem add Mg in aluminum alloy with SiC. SiCox2/ (Al + 2Mg) composites were prepared using SiC particles having an amorphous SiO2 layers. When the SiCox2+ Al composite is exposed at approximately 600°C, the SiO2 layer formed at the SiC surface. But reaction with Mg within the matrix alloy to form Si and MgAl2O4 crystals at the expense of SiO2 layer. Density of Si and MgAl2O4 crystals in this composite, and protect the entire surface of SiC, from the formation of Al4C3 upon exposing at temperatures above 620°C. This indicates that the interface not only was effective in protecting further reactions at the interface, but also possessed an excellent thermal stability at elevated temperatures. Therefore, combination of the passive oxidation of SiC and the Mg addition into the Al matrix was considered to be efficient for forming a stable interface in the SiC/Al composite. 10. R.K. Uyyuru et.al.(2005) studied the tribological behavior of stir-cast Al–Si/SiCp composites against automobile brake pad material was studied using Pin-on-Disc tribotester. The Al-metal matrix composite (Al-MMC) material was used as disc, whereas the brake pad material forms the pin. It has been found that both wear rate and friction coefficient vary with both applied normal load and sliding speed. With increase in the applied normal load, the wear rate was observed to increase whereas the friction coefficient decreases. Applied normal load is most important parameter on wear performance. Influence of speed and concentration of abrasives on the other hand seemed to be composition dependent. When the SiCp reinforcement in the matrix has wide size distribution, wear rate and friction coefficients are found to be higher compared with matrix containing nano-size reinforcement. Tribo-layer a thin adherent layer formed mostly DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 41 of pin material during the wear test-can act as a protective layer for the matrix material. Thus, the formation of tribo-layer can have a significant role to play in wear behavior of tribological couple made of Al–Si/SiCp MMC and brake pad during the service. 11. K. Manigandan et.al. (2012) presented and discussed the tensile properties and fracture characteristics of an Al–Cu–Mg alloy discontinuously reinforced with silicon carbide particulates (SiCp). The SiCp reinforcement phase in this Al–Cu–Mg alloy metal matrix, were near uniform in size. Few of the particles were found to be irregularly shaped and dispersed randomly through the metal matrix. The elastic modulus of the Al–Cu–Mg/SiC/15p-T42 composite is 93.91 GPa, which is 34% more than the elastic modulus of the matrix alloy with no SiCp reinforcement [70 GPa]. The ultimate tensile strength of the composite is noticeably higher than the yield strength by 38 pct, indicating the occurrence of strain hardening beyond yield. The presence of the hard, brittle and elastically deforming SiC particles in the soft, ductile and plastically deforming aluminum alloy metal matrix caused fine microscopic cracks to initiate at low values of applied stress. Fractography revealed limited ductility on a macroscopic scale, but microscopically features were reminiscent of locally ductile and brittle mechanisms. Fracture of the matrix between the clusters of reinforcing particles, coupled with particle failure by both cracking and decohesion at the matrix–particle interfaces allows the microscopic cracks to grow rapidly and link resulting in macroscopic failure and resultant minimal tensile ductility. 12. V. N. Gaitonde et. al. (2012) studied that among the several types of aluminum alloys being used; Al5000 series are widely used in marine and aerospace applications due to their superior corrosion resistance, excellent formability and good welding characteristics. Hence the proposed work to study the effects of Graphite (Gr) and Aluminium oxide (Al2O3) on aluminum hybrid composites involving both hard and soft reinforcements on wear and corrosion properties. The experimental investigations of wear and corrosion behavior of Al5083-Al2O3-Gr hybrid composites. The micro hardness of hybrid composites is higher when compared to matrix alloy. An increased content of hard reinforcement in the hybrid composites leads to the enhancement in micro hardness of hybrid composites. The immersion test on developed hybrid composites indicated that addition of graphite and Al2O3 in to the matrix have reduced mass loss under DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 42 identical test conditions. Increased graphite particles reduce the corrosion rate under identical test conditions. The hybrid composites possess marginally inferior cord- rosin resistance in 3.5% NaCl medium when com- pared with matrix alloy. 13. Xiaochun Li et.al. (2008) Theoretical and experimental study of dispersion of nanoparticles and found that it is very challenging to disperse nanoparticles uniformly in A356 melts for casting. In this study, the feasibility of ultrasonic cavitations based dispersion of nanoparticles in A356 was theoretically studied and validated by analytical modeling, particularly for a simplified two nanoparticle system in A356 melt. An experimental system for ultrasonic cavitations based solidification processing was fully developed and alloy A356 nanocomposites were fabricated and characterized. With optimized processing parameters, the tensile test results showed that, with only 1.0wt% nano-sized SiC, the ultimate tensile strength (UTS) and Yield strength of the nanocomposites were improved approximately 100% while ductility is retained. Micro or nano structure study shows that good nanoparticle distribution and dispersion in the Al matrix were achieved. 14. Rabindra Behera et.al. (2011) In the present investigation, the hardness and forge ability of stir cast LM6 reinforced with 5 and 10 wt% SiCp was examined at the different section of the stepped casting and the effect of weight percentage of SiCp on machinability of the cast MMCs has been evaluated. The forge ability i.e. percentage of deformation decreases on increasing the percentage of SiCp and the middle part of the casting (i.e. section–II) shows low forge ability comparison to the both end sections in the step casting component because accumulation of higher percentage of SiCp. That indicates the distribution of SiCp is not uniform throughout the casting. The machinability of MMC is different from the traditional materials because of presence abrasive reinforcement particles. During turning operation, the cutting forces have increased with increase in weight percentage of SiCp. That indicates the power consumption during machining of aluminium alloy MMCs will increases on increasing the depth of cut. The surface roughness of cast MMCs increasing with the increasing weight percentage of SiCp. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 43 15. Yasumasa Chino (2004) investigated the tensile properties and blow forming characteristics of 5083 Al alloy recycled by solid-state recycling. The results are three types of machined chip with different volumes were recycled by hot extrusion and hot rolling, and oxide contamination was investigated. Oxide layers, which were contaminants from the machined chip Surface, were distributed parallel to the extrusion direction in the recycled specimens. Oxygen concentration in the recycled specimens increased with the total surface area of the machined chips per unit volume. Therefore, the size of machined chips is an important factor for the control of the contamination level of oxides in solid-state recycling. The recycled specimens exhibited almost the same properties in term of strength and elongation to failure as the virgin specimen. However, at 773 K, the recycled specimens showed lower elongation than the virgin specimen, and the elongation decreased with increasing oxygen concentration. The same trend was found in the blow forming tests, that is, formability decreased with increasing oxygen concentration. Thus, oxide contamination has a detrimental effect on the formability of recycled Al alloy. 16. Soheyl Soleymani (2011) employed an innovative technique, friction stir processing (FSP) to modify the surface layer of Al5083 alloy. In the present investigation, an attempt has been made to study the effects of FSP and the number of passes on hardness and wear resistance of Al5083 alloy. Increasing the number of FSP passes also led to the improvement of hardness and wear resistance. These can be attributed to the micro structural refinement. Wear weight loss and friction coefficient decreased with decreasing the force applied during sliding. Increasing the number of FSP passes led to the decrease in weight loss and friction coefficient and also surface damages. This trend has been observed for the samples worn under lower applied forces and indicates that more FSP passes can result in the improvement of load bearing capacity of the alloy during sliding. 17. Suleiman Bolaji Hassan (2006) investigated the effects of varying silicon carbide on the hardness values of heat-treated Al–Si–Fe/SiC composites. The 5–25% SiC additions were used for the production of different grades of Al–Si–Fe/SiC composites. The composites samples were solution heat treated at 500 ◦C for 3 h and quenched in warm water at 65 ◦C, aged at 100, 200 and 300 ◦C with various ageing time between 60 and 660 min at 60 min interval. The DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 44 increase in the hardness values of the composites is due to the precipitates of the second phase during ageing which cover the surface at the particles matrix interfaces. The results obtained from the statistical analysis are in agreement with the experimental findings for these ageing time and temperatures. It was found that hardness increases with increasing weight fraction of silicon carbide in the alloy and decreases with increasing ageing time after the peak ageing time have exceeded. 18 A.K.Chaubey et.al. (2012) studied the two distinct approaches have been used for the dispersion of the reinforcing particles within the Al matrix: manual blending and ball milling. Manual blending leads to the agglomeration of the Al–Ca particles to form a cell network throughout the consolidated sample. On the other hand, the composites prepared by ball milling more homogeneous distribution of the reinforcing particles. This has a strong impact on the mechanical properties. Al-based metal matrix composites containing different volume fractions of nano crystal of Al–Ca reinforcing particles have been produced by powder metallurgy and the effect of the volume fraction of reinforcement and dispersion of the reinforcing particles on the mechanical properties of the composites. The strength increases from 112 MPa for pure Al to 140 and 165 MPa for the manual blended composites and with 20 and 40 vol.%, while the strength increases to 250 and 280 for the corresponding composites produced by ball milling due to small size and leads to higher strength as compared to the composites produced by manual blending. 19. Ali Mazahery et.al. (2012) experimental and modeling investigations were carried out on the porosity, wear, hardness, elongation, yield strength and ultimate tensile strength (UTS) of these nano-composites. The density measurements showed that the amount of porosity in the composites increased with increasing the volume fraction of nano-particles. The hard particles resist against destruction action of abrasive and protect the surface, so with increasing its content, the wear resistance enhances. Nano-hard particles acting as obstacles to the motion of dislocation. The addition of nanoparticles resulted in significant improvements in yield strength and UTS of the composites. Information obtained from the model predictions and simulations can be used as guidelines during the conceptual design and optimization of manufacturing DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 45 processes thus reducing the time and costs that would otherwise be incurred by experimental methods. 20. A r yazdipour (2011) investigated the microstructures and properties of aluminum alloy 5083 in two different types of welds, Metal Inert Gas (MIG) and Friction Stir Welding (FSW), have been used to weld aluminum alloy 5083. The microstructure of the welds, including the nugget zone and heat affected zone, has been compared in these two methods using optical microscopy. The mechanical properties of the weld have been also investigated using the hardness and tensile tests. However, FSW samples have shown higher strength in comparison to the MIG samples. The results also show that the extension of the heat affected zone is higher in the MIG method in comparison to the FSW method. The weld metal microstructure of MIG welded specimen contains equiaxed dendrites as a result of solidification process during MIG welding while FSW samples have wrought microstructures. 21. GU Wan-li (2006) studied of nano-sized Al-SiC powders were prepared by mechanical alloying method. Two of SiC particle, i.e. nano-sized and popular micron-sized Sic was utilized. Effects of the particle size and agglomerate state of SiC, as well as the microstructure of Al-SiC nanocomposite were studied by SEM and TEM. Popular micron ceramic Sic particles can be broken up to less than 100 nm and disperse in aluminium homogenously by ball milling the mixed Sic and Al powder for 10 h. This process needs only 2 h if the popular Sic particle is substituted by nanosized SiC. In the preparation of bulk composite, the reinforced ceramic particle in aluminium will agglomerate under an ordinary powder metallurgy condition such as hot pressing at 873 K and 10 MPa. However, the Sic particle about 20 to 50 nm will be dispersed uniformly in aluminium matrix at a hot pressing temperature of about 723 K under pressure of 100 MPa. 22. S. M. Zebarjad (2008) study concentrated on the role of particle size of silicon carbide (SiC) on dimensional stability of aluminum. Three kinds of Al-SiC composite reinforced with different SiC particle sizes (25 μm, 5 μm, and 70 nm) were produced using a high-energy ball mill. The standard samples were fabricated using powder metallurgy method. The samples were heated from room temperature up to 500◦C in a dilatometer at different heating rates, that is, 10, 30, 40, DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 46 and 60◦C/min. The results showed that for all materials, there was an increase in length change as temperature increased and the temperature sensitivity of aluminum decreased in the presence of both micro- and nanosized silicon carbide. At the same condition, dimensional stability of Al/SiC nanocomposite was better than conventional Al/SiC composites. 23. R. Palanivel et. al. (2011) studied that Aluminium alloys generally have low weld ability with the traditional fusion-welding process. However, the development of Friction Stir Welding (FSW) has provided an alternative, improved way of producing aluminium joints, in a faster and more reliable manner. The FSW process has several advantages, in particular the possibility to weld dissimilar aluminium alloys. This study focuses on the tensile behavior of dissimilar joints of AA6351-T6 alloy to AA5083-H111 alloy produced by friction stir welding. Five different tool pin profiles, such as Straight Square (SS), Tapered Square (TS), Straight Hexagon (SH), Straight Octagon (SO) and Tapered Octagon (TO), with three different welding speeds (50 mm/min, 63 mm/min, 75 mm/min) have been used to weld the joints. The effect of the pin profiles and the welding speed on the tensile properties was analyzed and it was found that the straight square pin profile with 63 mm/min produced a better tensile strength then the other tool pin profiles and welding speeds. 24. Rajesh Purohit et. al. theoretical and experimental study of ―CASTING OF Al-SiCp COMPOSITES AND TESTING OF PROPERTIES‖. Al-SiC p composites with 5, 10, 15, 20, 25 and 30 weight % of SiC p in the shape of solid cylindrical pins were fabricated using stir die casting process. The various properties viz. density, hardness, compressive strength, tensile strength, surface roughness and wear resistance were measured. The density, hardness, compressive strength and tensile strength of Al-SiC p composites were found to increase with increase in the weight % of SiC p from 5 to 30 weight percentage. The dry sliding wear tests using pin on disc wear testing machine reveal that the wear resistance of Al-SiC p composites increases with increase in reinforcement content from 10 to 20 weight % of SiC p while the wear resistance decreases on further increase in reinforcement content from 20 to 30 weight % of SiC p. Increased wear of Al-SiC p composites with higher weight % of SiC p composites is due to the removal of loosely bonded SiC particulates from the matrix. The average surface roughness (Ra DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 47 value) of cast Al-SiC p composites first decreases then increases with increase in reinforcement content of SiC particulates from 5 to 30 weight percent. The surface roughness values depend upon the extent of polishing done on the Al-SiC p composites. 25. S. O. Adeosun et. al. (2009) examines the effect of addition of 60 micron silicon carbide particles on the strength and ductility of a wrought aluminum alloy. Cast samples produced using metal mould contained up to 50 vol % volume fractions of SiCp with respect to the volume of aluminum. Some of the samples were heat treated at 430˚C for 8 hours and then normalized. The rest were not heat treated. Tensile tests were carried out after heat treatment on all the samples. This shown that addition of SiCp to wrought 1200 aluminum alloy can significantly increases its strength and elongation characteristics. Good UTS of 157 MPa and 158 MPa can be obtained in as-cast and normalized samples with 40 vol % and 50 vol % of SiCp respectively, while the elongations are 13 and 15% respectively. For a combination of strength and elongation as required in wrought alloys, addition of 20 vol % SiCp will give strength of 125 MPa and elongation of 23% for sample normalized. The presence of Al3Fe crystals and incoherent precipitation of intermetallics have been observed to improve elongation. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 48 CHAPTER-3 EXPERIMENTAL WORK DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 49 EXPERIMENTAL WORK 3.1- COMPOSITION ANALYSIS OF AL-ALLOY 5083: Composition analysis of Al-alloy 5083 were carried out in AMPRI Bhopal. Result of this analysis is shown in table 3.1 Al5000 series are extensively used in marine and aerospace applications because of their superior corrosion resistance, excellent formability and good welding characteristics. Al5000 series are broadly used for the construction of ship buildings/structures; however due to low strength and poor wear resistance the application of this series is limited.Al5083, a non-heat treatable high Mg-Al wrought alloy, is extensively used for the marine and automobiles applications(12). Table 3.1 percentage of composition in Al-alloy 5083 Element Zn Fe Ti Cu Si Pb Mn Mg Cr Al %Present 0.03 0.173 0.04 0.0181 0.16 0.0140 0.526 5.13 0.097 Balance 3.2- SEM ANALYSIS OF SIC PARTICLE: SEM analysis of SiC particles were carried out to find out the size of the particles present in SiC powder. Fig.3.1 SEM image of SiC macro composites DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 50 Fig.3.2 SEM image of SiC nano composites 3.3-AUTOMOTIVE GEAR-AN OVERVIEW: The power is transmitted from one shaft to the other by means of belts, chains and gears. The belts and ropes are flexible members which are used where distance between the two shafts is large. The chains also have flexibility but they are preferred for intermediate distances. The gears are used when the shafts are very close with each other. This type of drive is called positive drive because there is no slip. If the distance is slightly larger, chain drive can be used for making it a positive drive. Belts and ropes transmit power due to the friction between the belt or rope and the pulley. There is a possibility of slip and creep and that is why, this drive is not a positive drive. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 51 3.3.1- LAW OF GEARING: The law of gearing states that the common normal at the point of contact of two bodies which are in contact, while transferring motion, should always pass through a fixed point called pitch point on the line joining the centers of rotation of the two bodies. 3.3.2- TYPES OF GEARS:  SPUR GEARS GENERAL: Spur gears are the most commonly used gear type. They are characterized by teeth which are perpendicular to the face of the gear. Spur gears are by far the most commonly available, and are generally the least expensive. The basic descriptive geometry for a spur gear is shown in the figure below. LIMITATIONS: Spur gears generally cannot be used when a direction change between the two shafts is required. ADVANTAGES: Spur gears are easy to find, inexpensive, and efficient. Fig.3.3 Spur gear DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 52 Fig.3.4 Spur gear  HELICAL GEARS GENERAL: Helical gears are similar to the spur gear except that the teeth are at an angle to the shaft, rather than parallel to it as in a spur gear. The resulting teeth are longer than the teeth on a spur gear of equivalent pitch diameter. The longer teeth cause helical gears to have the following differences from spur gears of the same size:  Tooth strength is greater because the teeth are longer.  Greater surface contact on the teeth allows a helical gear to carry more load than a spur gear.  The longer surface of contact reduces the efficiency of a helical gear relative to a spur gear. Helical gears may be used to mesh two shafts that are not parallel, although they are still primarily use in parallel shaft applications. A special application in which helical gears are used is a crossed gear mesh, in which the two Shafts are perpendicular to each other. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 53 The basic descriptive geometry for a helical gear is essentially the same as that of the spur gear, except that the helix angle must be added as a parameter. LIMITATIONS:  Helical gears have the major disadvantage that they are expensive and much more difficult to find.  Helical gears are also slightly less efficient than a spur gear of the same size. ADVANTAGES:  Helical gears can be used on non parallel and even perpendicular shafts, and can carry higher loads than can spur gears. Fig.3.5 Helical gears DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 54 Fig 3.6 Crossed helical gear Fig 3.7 Herring bone gear  BEVEL GEARS GENERAL: Bevel gears are primarily used to transfer power between intersecting shafts. The teeth of these gears are formed on a conical surface. Standard bevel gears have teeth which are cut straight and are all parallel to the line pointing the apex of the cone on which the teeth are based. Spiral bevel gears are also available which have teeth that form arcs. Hypocycloid bevel gears are a special type of spiral gear that will allow nonintersecting, non-parallel shafts to mesh. Straight tool bevel gears are generally considered the best choice for systems with speeds lower than 1000 feet per minute: they commonly become noisy above this point. One of the most common applications of bevel gears is the bevel gear differential. LIMITATIONS:  Cannot be used for parallel shafts.  Can become noisy at high speeds. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 55 ADVANTAGES: Excellent choice for intersecting shaft systems. Fig 3.8 Bevel gear  WORM GEARS GENERAL: Worm gears are special gears that resemble screws, and can be used to drive spur gears or helical gears. Worm gears, like helical gears, allow two non-intersecting 'skew' shafts to mesh. Normally, the two shafts are at right angles to each other. A worm gear is equivalent to a V-type screw thread. Another way of looking at a worm gear is that it is a helical gear with a very high helix angle. Worm gears are normally used when a high gear ratio is desired, or again when the shafts are perpendicular to each other. One very important feature of worm gear meshes that is often of use is their irreversibility: when a worm gear is turned, the meshing spur gear will turn, but turning the spur gear will not turn the worm gear. The resulting mesh is 'self locking, and is useful in ratcheting mechanisms. LIMITATIONS:  Low efficiency.  The worm drives the drive gear primarily with slipping motion, thus there are high friction losses. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 56 ADVANTAGES:  Will tolerate large loads and high speed ratios.  Meshes are self locking (which can be either an advantage or a disadvantage). Fig. 3.9 Worm gear  RACKS (STRAIGHT GEARS) GENERAL: Racks are straight gears that are used to convert rotational motion to translational motion by means of a gear mesh. (They are in theory a gear with an infinite pitch diameter). In theory, the torque and angular velocity of the pinion gear are related to the Force and the velocity of the rack by the radius of the pinion gear, as is shown below: Perhaps the most well-known application of a rack is the rack and pinion steering system used on many cars in the past. LIMITATIONS:  Limited usefulness.  Difficult to find. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 57 ADVANTAGES:  The only gearing component that converts rotational motion to translational motion.  Efficiently transmits power.  Generally offers better precision than other conversion methods. Fig.3.10 Miter gear Fig.3.11 Internal gear Fig. 3.12 Spiroid gear Fig. 3.13 Angular gear DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 58 3.4 CASTING OF CURCULAR DISC BY STIR CASTING: STEPS OF CASTING: 1. Cut the aluminum alloy-5083 ingot weight it and put it in the ceramic crucible in the electric resistance furnace. Fig.3.14 Ceramic crucible 2. Start the electric furnace and set the casting temperature 800ºC. 3. Three castings were done. One for AA5083/10% micron SiC one for AA5083/1% nano SiC and one foe AA5083/2% nano SiC. When aluminum alloy-5083 fully melt than added SiC particles 10% micron by weight,1% nano and 2% nano SiC by weight . DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 59 Fig. 3.15 Furnace with stirrer and nitrogen cylinder 4. After addition of SiC particles it mixed by Mechanical stirring. 5. After the fully mixing of SiC particles. Than crucible take out from the furnace. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 60 Fig.3. 16 Line diagram of stir casting DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 61 Fig.3. 17 Crucible grabber Fig. 3. 18 Hand gloves DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 62 6. Melt was poured in the pre heated mild steel disc die (diameter-62mm, thickness-17mm) for circular disk and hollow cylindrical die (20 mm dia.) for tensile, compression & hardness specimen.. Fig. 3.19 Die heater DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 63 Fig. 3.20 Dies for 20 mm dia. rod 7. After solidification of melt casted circular disc were were removed from die. Fig. 3.21 Al-alloy (5083) circular disc DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 64 Fig. 3.22 Al-alloy with 10% sic composites circular disc Fig. 3.23 Tensile specimen DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 65 Fig. 3.24 Hardness and Compression specimen 8. Machining on circular disc was done on lathe machine to get the gear of required dimensions (diameter-57m.m, thickness-12 m.m). 9. After being machined cut the teeth over circular disc by milling machine (28 teeth). DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 66 Fig. 3.25 Final gears made up of composites 3.5-HARDNESS TEST: Fig. 3.26 Hardness testing set up Tested the hardness values of cast specimen of Al-alloy, Al-alloy with 10% SiC composites, Al- alloy with 1% nano composites, and Al-alloy with 2% nano composites measured on the the various point of the polished surfaces of the samples using B scale on Rockwell hardness tester. 3.6- TENSILE STRENGTH AND COMPRESSION STRENGTH TESTS: Tensile strength and Compressive strength tested of cast specimen of Al-alloy, Al-alloy with 10% SiC composites, Al-alloy with 1% nano composites, and Al-alloy with 2% nano composites measured on the polished surfaces of the samples using U.T.M tester. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 67 Fig. 3.27 Universal testing machine 3.7 WEAR TESTING OF GEAR: Required setup for wear testing was fabricated which is shown in figure 3.28. STEPS: 1. First of all measure the initial weight of gears. 2. Now mount the gear on shaft on the setup. 3. Apply 1 kg load on the drive shaft with the help of mild steel strip (shown in fig.). 4. Than start the motor which rotate the meshing gear at constant speed 1470 r.p.m.for 1 hous. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 68 Fig. 3.28 Wears testing set up for gear 6. After 1 hrs stop the motor and take out the gear from the setup. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 69 7. Now measure the weight of gear. 8. Find the difference of weight will be the wear rate in weight in 1 hrs. Fig -3.29 Weighting machine 9. Similar measurements procedure were follow for the wear rate for 2 and 3 hrs for 1 kg. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 70 10. Similar measurements procedure were follow for the wear rate 2 and 3 kg in 1, 2 and 3 hrs respectively. 11. In summary , the wear rate of Al-alloy gears, 10% SiC composites gears ,1% nano composites gears ,and 2% nano composites at 1 kg(1,2,& 3 hrs), 2kg(1,2,&3 hrs) and 3 kg(1,2,& 3hrs).were measured. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 71 CHAPTER-4 RESULTS & DISCUSSIONS DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 72 RESULTS AND DISCUSSIONS 4.1 HARDNESS TEST: The average Rockwell hardness values of cast Al-alloy, Al-alloy with 10% SiC composites, Al- alloy with 1% nano composites, and Al-alloy with 2% nano composites measured on the polished surfaces of the samples using B scale on Rockwell hardness tester are shown in Fig.4.1. Table 4.1 Hardness of composite Composition Hardness (HRB) Al alloy 28.4 Al alloy with 10%sic composite 43.9 Al alloy with 1%sic nano composite 39.8 Al alloy with 2%sic nano composite 47.4 The hardness of Al-alloy with 2% SiC nano composite is more among all tested composition. But hardness of Al alloy with 10%sic composite is more than Al alloy with 1%sic nano composite. 4.2. TENSILE STRENGTH TEST: The average tensile strength values of cast Al-alloy, Al-alloy with 10% SiC composites, Al-alloy with 1% nano composites, and Al-alloy with 2% nano composites measured on the polished surfaces of the samples using U.T.M tester. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 73 Table 4.2 Tensile strength of composites Composition Tensile Strength (MPa) Al alloy 223.4 Al alloy with 10%sic composite 238.4 Al alloy with 1%sic nano composite 251.8 Al alloy with 2%sic nano composite 272.3 The tensile strength of Al alloy with 2% SiC nano composite is more among all tested composition. 4.3 COMPRESSION STRENGTH TESTS: The average compression strength values of cast Al-alloy, Al-alloy with 10% SiC composites, Al-alloy with 1% nano composites, and Al-alloy with 2% nano composites measured on the polished surfaces of the samples. Table 4.3 Compression strength of composites The compression strength of Al alloy with 2% SiC nano composite is more among all tested composition. Composition Compression Strength (MPa) Al alloy 312 Al alloy with 10%sic composite 336 Al alloy with 1%sic nano composite 389.5 Al alloy with 2%sic nano composite 529.5 DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 74 4.4 WEAR TEST OF GEAR: Make the table of wear loss in 1, 2 and 3 hrs at 1, 2 and 3kg. 4.4.1 COMPOSITION- Al-alloy:  Load applied- 1 kg Table 4.4 Weight losses in mg at 1 kg of Al-alloy INITIAL WEIGHT 1 hr 2 hr 3 hr gear1 74.3231 74.26687 74.1515 73.98164 Wear 0.05623 0.11537 0.16986 Gear 2 78.16235 78.10893 78.00104 77.83576 wear 0.05342 0.10789 0.16528  Load applied-2 kg Table 4.5 Weight losses in mg at 2 kg of Al-alloy Initial weight 1hr 2hr 3hr Gear1 73.98164 73.91382 73.7771 73.57038 Wear 0.06782 0.13672 0.20672 Gera2 77.83576 77.77063 77.63938 77.4296 Wear 0.06513 0.13125 0.19642  Load applied-3 kg Table 4.6 Weight losses in mg at 3 kg of Al-alloy Initial weight 1hrear 2hr 3hr Gear1 73.57038 73.49807 73.35275 73.13522 Wear 0.07231 0.14532 0.21753 Gear2 77.44296 77.37373 77.23416 77.01878 wear 0.06923 0.13957 0.21538 DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 75 4.4.2 COMPOSITION- Al-alloy with 10% SiC composites:  Load applied-1 kg Table 4.7 Weight losses in mg at 1 kg of 10% sic composites Initial weight 1hr 2hr 3hr Gear1 73.66285 73.6147 73.5171 73.37143 Wear 0.04815 0.0976 0.14567 Gera2 76.8062 76.75868 76.6628 76.5198 Wear 0.04752 0.09585 0.14325  Load applied-2 kg Table 4.8 Weight losses in mg at 2 kg of 10% sic composites Initial weight 1hrear 2hr 3hr Gear1 73.37143 73.31752 73.2086 73.04587 Wear 0.05391 0.10892 0.16273 Gear2 76.5198 76.46342 76.35018 76.18046 wear 0.05616 0.11324 0.16972  Load applied-3 kg Table 4.9 Weight losses in mg at 3 kg of 10% sic composites Initial weight 1hr 2hr 3hr Gear1 73.04587 72.97642 72.83122 72.62199 Wear 0.06945 0.1452 0.20923 Gear 2 76.18046 76.11512 75.98339 75.78577 Wear 0.06534 0.13173 0.19762 DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 76 4.4.3 COMPOSITION- Al-alloy with 1% nano composites:  Load applied- 1 kg Table 4.10 Weight losses in mg at 1 kg of 1% sic nano composites Initial weight 1hr 2hr 3hr Gear1 65.60956 65.56031 65.46101 65.31312 Wear 0.04925 0.0993 0.14789 Gera2 64.01249 63.96115 63.85753 63.7033 Wear 0.05134 0.10362 0.15423  Load applied-2 kg Table 4.11 Weight losses in mg at 2 kg of 1% sic nano composites Initial weight 1hr 2hr 3hr Gear1 65.31312 65.2597 65.15187 64.99051 Wear 0.05342 0.10783 0.16136 Gear2 63.7033 63.64387 63.52405 63.34482 wear 0.05943 0.11982 0.17923  Load applied- 3kg Table 4.12 Weight losses in mg at 3 kg of 1% sic nano composites Initial weight 1hr 2hr 3hr Gear1 64.99051 64.92919 64.80595 64.62143 Wear 0.06132 0.12324 0.18452 Gera2 63.34482 63.2763 63.13817 62.93165 Wear 0.06534 013813 0.20652 DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 77 4.4.4 COMPOSITION- Al-alloy with 2% nano composites:  Load applied- 1 kg Table 4.13 Weight losses in mg at 1 kg of 2% sic nano composites Initial weight 1hr 2hr 3hr Gear1 66.17725 66.14085 66.06495 65.95515 Wear 0.0364 0.0759 0.1098 Gera2 66.75004 66.71474 66.63824 66.53034 Wear 0.0353 0.0765 0.1079  Load applied- 2 kg Table 4.14 Weight losses in mg at 2 kg of 2% sic nano composites Initial weight 1hrear 2hr 3hr Gear1 65.9515 65.91565 65.83615 65.71725 Wear 0.0395 0.0795 0.11891 Gear2 66.53034 66.49184 66.41334 66.29644 wear 0.0385 0.0785 0.0169  Load applied- 3 kg Table 4.15 Weight losses at 3 kg of 2% sic nano composites Initial weight 1hr 2hr 3hr Gear1 65.71725 66.42774 65.59318 65.46906 Wear 0.04132 0.08275 0.12412 Gera2 66.29644 66.25323 66.16631 66.03379 Wear 0.0321 0.08692 0.13252 DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 78 4.5 GRAPHICAL REPRESENTATION OF WEIGHT LOSS w.r.t TIME OF WEAR TEST: Graph 4.1 Aluminium alloy Graph 4.2 Al-alloy with 10% sic composite 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 1 2 3 w e i g h t l o s s ( g m s ) time (Hrs) 3kgs 2kgs 1 kg. 0 0.1 0.2 0.3 0.4 0.5 0.6 1 2 3 w e i g h t l o s s ( g m s ) time (Hrs) 3kgs 2kgs 1 kg. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 79 Graph 4.3 Al- alloys with 1% nano composite Graph 4.4 Al- alloys with 2% nano composite We can see that in graph when load increased than weight loss also increased with respect to time. 0 0.1 0.2 0.3 0.4 0.5 0.6 1 2 3 w e i g h t l o s s ( g m s ) time (Hrs) 3kgs 2kgs 1 kg. 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 1 2 3 w e i g h t l o s s ( g m s ) time (Hrs) 3kgs 2kgs 1 kg. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 80 Graph 4.5 variation of weight loss V/S time for different composites with respect to time We can see that in the graph weight loss is minimum in Al-alloy 2% nano composites among the entire tested component. But weight loss in 10% SiC composites is less as compare to 1% nano composites. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 81 CHAPTER-5 CONCLUSIONS DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 82 CONCLUSION 1. Aluminium matrix composite automotive gear is successfully fabricated with Aluminium alloy, Al- alloy with 10 % SiC composite and Al-alloy with 1% & 2% nano SiC composite. 2. The mechanical properties i.e tensile strength, compressive strength, and hardness of the above material were also tested. 3. It is found that Al-alloy with 2% nano composites have more tensile strength, compressive strength and hardness among the tested components. But hardness of Al- alloy with 10%sic composite is more than Al alloy with 1% SiC nano composite. 4. A setup for wear testing for gear design and fabricated than wear test of all gear was done at different load (1,2,3kg) and time(1,2,3hrs). Al-alloy with 2% nano SiC composite gear perform to have lowest wear loss and have high wear resistance among the tested component. 5. Al-alloy with 10% SiC has more wear resistance than Al-alloy with 1% nano composite. 6. The fabricated aluminium nano composite gear have light weight about 1/3 of steel and good wear resistance .hence can be substituted existing material used for automobiles. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 83 REFERENCES DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 84 REFERENCES 1. Rick Borns and Don Whitacre,‖ Optimizing Designs of Aluminum Suspension Components Using an Integrated Approach‖, Journal of SAE Paper 05M-2 (2005). 2. Anthony Macke, B.F. Schultz and Pradeep Rohatgi ―Metal Matrix Composites Offer the Automotive Industry an Opportunity to Reduce Vehicle Weight, Improve Performance‖ Journal of ADVANCED MATERIALS & PROCESSES (2012). 3. Manoj Singla, D. Deepak Dwivedi, Lakhvir Singh and Vikas Chawla, ―Development of Aluminium Based Silicon Carbide Particulate Metal Matrix Composite‖ Journal of Minerals & Materials Characterization & Engineering Vol. 8, No.6, pp 455-467 (2009). 4. S.DAS ―Development of Aluminium Alloy Composites for Engineering Applications‖ Journal of Metal Composite Group, Regional Research Laboratory (CSIR), Bhopal (M.P) (2004). 5. G. B. Veeresh Kumar, C. S. P. Rao and N. Selvaraj ―Mechanical and Tribological Behavior of Particulate Reinforced Aluminum Metal Matrix Composites‖ Journal of Minerals & Materials Characterization & Engineering Vol. 10, No.1, pp.59-91 (2011). 6. G. G. Sozhamannan, S. Balasivanandha Prabu, V. S. K. Venkatagalapathy ‘‘ Effect of Processing Paramters on Metal Matrix Composites: Stir Casting Process‖ (2011). 7. Yong Yang, Jie Lan, Xiaochun Li ―Study on bulk aluminum matrix nano-composite fabricated by ultrasonic dispersion of nano-sized SiC particles in molten aluminum alloy‘‘ Journal of Materials Science and Engineering A 380 (2004) 378–383(2004). 8. Ya-Cheng Lin, Paul J. McGinn, Alexander S. Mukasyan ―High temperature rapid reactive joining of dissimilar materials: Silicon carbide to an aluminum alloy‖ Journal of the European Ceramic Society 32 (2012) 3809–3818. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 85 9. Jae-Chul Lee, Jae-Pyoung Ahn, Jae-Hyeok Shim, Zhongliang Shi, and Ho-In Lee(1999) ―CONTROL OF THE INTERFACE IN SiC/Al COMPOSITES‖ Scripta Materialia, Vol. 41, No. 8, pp. 895–900 (1999) , Elsevier Science Ltd. 10. R.K. Uyyuru, M.K. Surappa, S. Brusethaug ‖Tribological behavior of Al–Si–SiCp composites/automobile brake pad system under dry sliding conditions‖ Journal of Tribology International 40 (2007) 365–373. 11. K. Manigandana, T.S. Srivatsanb, T. Quickc ‖Influence of silicon carbide particulates on tensile fracture behavior of an aluminum alloy‖ Journal of Materials Science and Engineering A 534 (2012) 711– 715. 12. V. N. Gaitonde1, S. R. Karnik2, M. S. Jayaprakash1‖ Some Studies on Wear and Corrosion Properties of Al5083/Al2O3/Graphite Hybrid Composites‖ Journal of Minerals and Materials Characterization and Engineering, 11 (2012), 695-703. 13. Xiaochun Li, Yong Yang, David Weiss ―Theoretical and experimental study on ultrasonic dispersion of nanoparticles for strengthening cast Aluminum Alloy A356‖ Journal of Metallurgical Science and Technology Vol. 26-2 - Ed. 2008. 14. Rabindra Behera, S.Das, D.Chatterjee, G. Sutradhar ―Forge ability and Machinability of Stir Cast Aluminum Alloy Metal Matrix Composite‖ Journal of Minerals & Materials Characterization & Engineering, Vol. 10, No.10, pp.923-939(2011). 15. Yasumasa Chino, Mamoru Mabuchi, Hajime Iwasaki,Atsushi Yamamoto and Harushige Tsubakino ‖ Tensile Properties and Blow Forming of 5083 Aluminum Alloy Recycled by Solid- State Recycling‖ Materials Transactions, Vol. 45, No. 8 pp. 2509 to 2515(2004). 16. Soheyl Soleymani, Amir Abdollah-zadeh, Sima Ahmad Alidokht― Improvement in Tribological Properties of Surface Layer of an Al Alloy by Friction Stir Processing‖ Journal of Surface Engineered Materials and Advanced Technology, 1, 95-100(2011). DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 86 17. Suleiman Bolaji Hassan , Victor Sunday Aigbodion ―Experimental correlation between varying silicon carbide and hardness values in heat-treated Al–Si–Fe/SiC particulate composites ‖ Journal of Materials Science and Engineering A 454–455 , 342–348(2006). 18. A.K. Chaubeya, S. Scudinoa, N.K. Mukhopadhyay, M. Samadi Khoshkhoo, B.K. Mishra, J. Eckert ― Effect of particle dispersion on the mechanical behavior of Al-based metal matrix composites reinforced with nanocrystalline Al–Ca intermetallics‖ Journal of Alloys and Compounds 536S , S134– S137(2012). 19. Ali Mazahery, Mohsen Ostad Shabani ―Nano-sized silicon carbide reinforced commercial casting aluminum alloy matrix: Experimental and novel modeling evaluation‖ Journal of Powder Technology 217 (2012) 558–565(2012). 20. A R YAZDIPOUR1, A SHAFIEI M and H JAMSHIDI AVAL ―An investigation of the microstructures and properties of metal inert gas and friction stir welds in aluminum alloy 5083‖ Journal of Sadhana Vol. 36, Part 4, pp. 505–514c Indian Academy of Sciences(2011). 21. GU Wan-li ―Bulk AVSiC nanocomposite prepared by ball milling and hot pressing method‖ Journal of Trans. Nonferrous Met. SOC. china 16~398-s401 (2011). 22. S.M. Zebarjad, S.A.Sajjadi, E.Z.Vahid Karimi ―Influence of Nanosized Silicon Carbide on Dimensional Stability of Al-SiC Nanocomposite‖ Journal of Hindawi Publishing Corporation Research. Letters in Materials Science Volume, Article ID 835746, 4 pages doi:10.1155/2008/835746 (2008). 23. R. Palanivel1, P.Koshy Mathews ―THE TENSILE BEHAVIOUR OF FRICTION- STIRWELDED DISSIMILAR ALUMINIUM ALLOYS‖ Journal of MTAEC9, 45(6)623(2011). 24. Rajesh Purohit and Rakesh Sagar ―CASTING OF Al-SiC p COMPOSITES AND TESTING OF PROPERTIES―. DEVELOPMENT AND ANALYSIS OF AUTOMOTIVE GEAR USING ALUMINIUM MATRIX COMPOSITES 87 25. S.O. Adeosun1,S.A.Balogun, O.S. Sanni and W.A.Ayoola ―IMPROVING THE STRENGTH AND DUCTILITY OF WROUGHT ALUMINUM THROUGH PARTICLE ADDITION‖ Journal of Materials Science and Technology (MS&T) (2009).