UNIT-IIIMetal Matrix Composites Lecture-3 08/19/15 1 Various types of Metal matrix composites. diffusion bonding. Liquid state processing. In situ processes. Effect of reinforcements on properties Volume fraction – Rule of mixtures. solid state processing .Metal Matrix Composites Characteristics of MMCs.Powder metallurgy.stir casting. squeeze casting infiltration. applications of MMCs . Applications of polymer matrix composites . Spray lay-up processes. Filament winding. Pultrusion. Compression molding- Stir casting & squeeze casting SMC Reinforced reaction injection molding. Resin transfer molding.Polymer Matrix Composites Syllabus Processing of polymer matrix composites Liquid state processing- Hand lay-up. short fibers) is mixed with a molten matrix metal by means of mechanical stirring. in which a dispersed phase (ceramic particles. The liquid composite material is then cast by conventional casting methods and may also be processed by conventional Metal forming technologies. Stir Casting is a liquid state method of composite materials fabrication.Stir casting The simplest and the most cost effective method of liquid state fabrication is Stir Casting. . Stir Casting Process . Stir Casting is characterized by the following features: Content of dispersed phase is limited (usually not more than 30 vol%). Distribution of dispersed phase throughout the matrix is not perfectly homogeneous . .PROCESS Melting of matrix material in induction furnace in crucible. Running the stirrer with optimum seed for the mixing of matrix and reinforcements Pouring the mixed liquid into the preheated die Allow the mould to solidify. Removing the component into the die. Preheating of die and reinforcements. Pouring of Particles in to the crucible. Spray lay-up processes. Resin transfer molding. Applications of polymer matrix composites .Polymer Matrix Composites Syllabus Processing of polymer matrix composites Liquid state processing- Hand lay-up. Pultrusion. Filament winding. Compression molding- squeeze casting SMC Reinforced reaction injection molding. Squeeze Casting Infiltration method is similar to the Squeeze casting technique used for metal alloys casting. using a movable mold part (ram) for applying pressure on the molten metal and forcing it to penetrate into a performed dispersed phase.Squeeze Casting Infiltration Forcing the liquid metal into a fibrous preform Squeeze Casting Infiltration is a forced infiltration method of liquid phase fabrication of Metal Matrix Composites. placed into the lower fixed mold part. . Squeeze Casting Infiltration . Vertical and Horizontal shot sleeve . The method is used for manufacturing simple small parts (automotive engine pistons from aluminum alloy reinforced by alumina short fibers) . The part is removed from the mold by means of the ejector pin. The upper movable mold half (ram) moves downwards and forces the liquid metal to infiltrate the pre form. The infiltrated material solidifies under the pressure. fibers) is placed into the lower fixed mold half.Squeeze Casting steps A preform of dispersed phase (particles. A molten metal in a predetermined amount is poured into the lower mold half. . Features of SQZ and Applied Parts . Components . Components .