Mterials & manufacture 2 - Essay Example

Metal matrix composites have been receiving significant attention in recent years, particularly in the area of processing techniques. In many instances the properties of a reinforced metal have been shown to provide a performance advantage over monolithic metal, but the high cost of producing the composite has prohibited widespread commercial use. Of the many potential metal matrix systems, aluminum alloy matrix composites have been the object of much research, primarily due to the light weight, low cost, and ease of fabrication of aluminum.

Within the class of Aluminum alloy matrix composites there exist two distinct material systems, namely (i) discontinuously reinforced composites, with the reinforcement taking the form of a particle, a platelet, a whisker, or a chopped fiber, and (ii) continuously reinforced composites, with the reinforcement being a unidirectional or a multidirectional array of continuous fibers. Discontinuously reinforced aluminum alloys have been fabricated by various means, including solidstate processes, such as powder metallurgy techniques (blending of metal and ceramic powders followed by hot pressing) [2], and liquid-state processes, such as compocasting (blending ceramic powder and molten aluminium, agitating and casting) and pressurized liquid-metal infiltration.

During this practice work, we had study a Metal Matrix Composite (MMC). This MMC contains 10% of Aluminium oxide or Alumina (reinforcement) and 90% of Aluminium alloy matrix (2618A). The aim of MMC is to improve the properties of this material. Indeed, Aluminium is ductile and Alumina (Al203) is stiff and strong. When we combine these two materials we obtain a composite with better properties. The aim of this laboratory it’s to compare the “green” density with the sintered density. Moreover, we can see the different structures, between “green” and sintered density, by an electron microscope available in the