A comparative study on abrasive wear behavior of semisolid–liquid processed Al–Si matrix reinforced with coated B₄C reinforcement

Abstract

A comparative study on abrasive wear behavior of the sol–gel coated B₄C particulate reinforced aluminum metal matrix composite has been carried out in the present investigation. In general, composites offer superior wear resistance as compared to the alloy irrespective of applied load and B₄C particles volume fraction. This is primarily due to the presence of the hard dispersoid which protects the matrix from severe contact with the counter surfaces, and thus results in less wear, lower coefficient friction and temperature rise in composite as compared to that in the alloy. The wear sliding test disclosed that the weight loss of the coated B₄C reinforced composites decreases with increasing volume fraction of B₄C particulates. The wear rate in all the samples increases marginally with applied load prior to reaching the critical load. It is ascribed to the increase in fracture of reinforcement, the penetration of hard asperities of the counter surface into the softer pin surface and micro cracking tendency of the subsurface. After the critical load there is a transition from smooth linear increase wear rate to sudden increase in wear rate. This is attributed to the significantly higher frictional heating and thus the localized adhesion and softening of the surface with the counter surface.