Combined effect of reinforcement and heat treatment on the two body abrasive wear of aluminum alloy and aluminum particle composites

An attempt has been made to study the two body abrasive wear behavior of LM13 alloy and LM13-15 wt.% SiC composite, in cast and heat-treated conditions, as a function of applied load. The wear constant (K) was calculated based on the wear rate data, which signifies the probability of formation of wear particles during abrasive wear process. It was observed that the wear constant decreases with load. In the case of cast alloy the value of wear constant was higher than that of the heat-treated alloy and composite. The wear surface and the subsurface were studied using scanning electron microscope (SEM). The wear surface and subsurface studies indicated that at low load regime (similar to1 N) the fragmentation of the wear surface is more by cracking, however, at high load regime plastic deformation is dominated. During the wear process, the cracks are mainly nucleated at the Al/Si and Al/SiC interfaces and joining the cracks forming the wear debris. Heat-treated alloy and composite showed better strength and hardness, resulted in less propensity for crack nucleation and showed enhancement in wear resistance. The subsurface studies showed plastic deformation and formation of mechanically mixed layer consisting of SiC particle, silicon and deformed Al. The subsurface deformation clearly depicts the propagation of cracks in longitudinal as well as in transverse directions in low load condition. However at high load, the SiC particles are seen embedded in the plastically deformed matrix. Pullout of SiC particles from the Al matrix was not observed. (C) 2004 Published by Elsevier B.V.