Lec3-Stir casting& Squeeze casting.ppt

April 2, 2018 | Author: guru prasad | Category: Casting, Composite Material, Fiberglass, Materials Science, Industries


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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 .
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