Development of Al-Al2o3 nanocomposites by stir casting followed by hot forging and heat treatment and testing of their properties

Abstract

In recent years, the reinforcement materials used in aluminum matrix composites are aluminum oxide, silicon carbide, titanium carbide and tungsten carbide in nano and micron size. The secondary processing of particle reinforced composites offers substantial benefits such as vanishing of defects, improvement in distribution of particles and thereby enhances their properties. In this study the properties of the hot forged and heat-treated nanocomposites were evaluated and compared with as cast and cast & heat-treated nanocomposites. Al6061-Al2O3 nanocomposites fabricated by varying the weight percentage of Al2O3 with 0, 2.5, 3.0, 3.5 and 4.0 in Al6061 alloy. After Casting, Al6061-Al2O3 composites were subjected to hot forging and heat treatment. Aluminum matrix nanocomposites were subjected to various tests to study their physical and mechanical properties. FESEM, EDAX and microhardness test of the developed composite have been carried out. The results revealed that among all the Cast, Heat treated and Hot Forged-Heat treated nanocomposites, the composites reinforced with 3.5 wt% Hot Forged-Heat treated composites have shown excellent micro structural homogeneity with uniform distribution of particles. It has been observed that mechanical properties like tensile strength, impact strength and Compressive strength, of hot forged-heat treated composites reinforced with 3.5 wt% possessed maximum values. Further, increase in wt.% resulted in decrease in properties due to clustering and non-uniform distribution of nanoparticles at 4 wt%.