Workability analysis on Aluminium based composites and Aluminium alloys

Abstract

Aluminium alloys have been used in advanced applications because of their combination of high strength, low density, durability, machinability and cost. These properties make it a very attractive compared to other materials. Among the aluminium alloys, Al-5Si, Al-4Mg and RR58 are commonly put in to use such as constructing aircrafts, wheels, roofing materials, sports goods etc. Aluminium in its pure form and as alloy has been reinforced with silicon carbide particulate and commonly exist in various applications. In the field of metal matrix composites(MMCs), particle reinforced matrix materials have been considered to be a viable alternative for steel in automobile, machine building and aircraft industries due to its higher stiffness ratio, improved wear resistance, superior fracture toughness etc., Aluminium MMCs with silicon carbide (SiCp) and aluminium Oxide (Al2O3) as reinforcement have significant advantage over conventional materials. The inclusion of hard particles in the ductile matrix materials by and large, improves the mechanical and metallurgical properties, but ductility decreases to a lesser extent. These MMCs are fabricated by employing several techniques such as powder metallurgy(P/M), liquid metallurgy and squeezing-casting. Among the various techniques, powder metallurgy method is widely adopted in industries since it provides many technical and economical benefits over conventional manufacturing processes. However, P/M products generally are susceptible by the inherent residual porosity which deteriorates the mechanical andmetallurgical properties. The sequence of P/M process comprises of blending powders with or without lubricant, compaction, ejection, sintering etc. Compaction was successfully carried out in the designed and fabricated tooling so as to prepare aluminium based metal matrix composites and aluminium alloys by powder metallurgy route.