ClassificationMaterials of Engineering Show/Hide Page Index « Previous Next » Basic Classification of Engineering Materials Basically Engineering Materials Can be classified into two categories1. Metals 2. Non-Metals Metals Metals are polycrystalline bodies which are having number of differentially oriented fine crystals. Normally major metals are in solid states at normal temperature. However, some metals such as mercury are also in liquid state at normal temperature. All metals are having high thermal & electrical conductivity. All metals are having positive temperature coefficient of resistance. Means resistance of metals increase with increase of temperature. Examples of metals – Silver, Copper, Gold, Aluminum, Iron, Zinc, Lead, Tin etc. Metals can be further divided into two groups1. Ferrous Metals – All ferrous metals are having iron as common element. All ferrous materials are having very high permeability which makes these materials suitable for construction of core of electrical machines. Examples: Cast Iron, Wrought Iron, Steel, Silicon Steel, High Speed Steel, Spring Steel etc. 2. Non-Ferrous Metals- All non-ferrous metals are having very low permeability. Example: Silver, Copper, Gold, Aluminum etc. Non-Metals Non-Metal materials are non-crystalline in nature. These exists in amorphic or mesomorphic forms. These are in both solid & gases forms at normal temperature. Normally all non-metals are Lustre Metals possess metallic Generally do not posses lustre lustre (Except graphite Other classification of engineering materials: . Hardness Generally hard Hardness is generally v 7. Density High density Low density 5. 2. Valance electrons are free to Valence electrons are ti move with in metals which makes them good conductor bound with nucleus whi free to move. Rubber.bad conductor of heat & electricity. Leathers. Malleability Malleable Non malleable 8. Brittleness Generally non brittle in nature Brittleness varies mater material 10. Difference between Metals and Non Metals Sl. No. electrons & conductivity Generally metals are slid Non-Metals All Non-metals are havi amorphic & mesomorph structure State varies material to Some are gas state and normal temperature in solid state at normal temperature. As these non-metals are having very high resistivity which makes them suitable for insulation purpose in electrical machines. This mak of heat & electricity bad conductor of heat & 4. Asbestos etc. Ductility Ductile Non ductile 9. 1. Property Metals Structure All metals are having crystalline structure State Valance 3. Strength High strength Low strength 6. Examples: Plastics. Super Alloys etc. Example: Steels. garnet. low temperature coefficient of resistance. Organic Materials: All organic material are having carbon as a common element. To overcome this draw back alloys are used. Gunmetal. Alloys are the composition of two or more metals or metal & non-metals together. PVC. hydrogen & other non-metallic substances. Chemical & Thermal properties. These ceramic materials are now extensively used in different engineering fields. These are made of inorganic compounds such as Oxides. Pure metals are having very low mechanical strength. Examples: Silica. Synthetic Rubbers etc. Organic Materials Metals & Alloys: Metals are polycrystalline bodies which are have number of differentially oriented fine crystals. Generally organic materials are having complex chemical bonding. Zno. cement. However. Brass. Bronze. which sometimes does not match with the mechanical strength required for certain applications. Normally major metals are in solid states at normal temperature. some metals such as mercury are also in liquid state at normal temperature. « Previous Next » Electrical Engineering Objective Questions MCQ Electrical Conductor Electrical Engineering Materials Classification of Electrical Engineering Materials Physical Properties of Materials Digital Sequential Switching Circuit .Engineering materials can also be classified as below1. SiC etc. Mgo. 2. Magnetic. Alloys are having good mechanical strength. Cds. In organic materials carbon is chemically combined with oxygen. Example: Plastics. Invar. Silicides and Carbides. Ceramic Materials: Ceramic materials are non-metallic solids. Electrical. concrete. Nitrides. Metals & Alloys Ceramic Materials 3. Ceramic materials possess exceptional Structural. glass. Mechanical Properties of Engineering Materials Latches and Flip Flops Chemical Properties of Materials Digital Encoder or Binary Encoder Electrical Properties of Engineering Materials Magnetic Properties of Engineering Materials Selection of Material for Engineering Application Bases of existence of properties in materials Factors Effecting the Resistivity of Electrical Materials Classification of Electrical Conducting Material Temperature Coefficient of Resistance Low Resistivity or High Conductivity of Conducting Material High Resistivity or Low Conductivity Conducting Material Materials used for Heating Elements Materials used for Precious Works Materials for Lamp Filaments Materials used for Rheostats Materials Used for Transmission Line Conductor .