Microstructure and Wear Properties of Aluminum Metal Matrix Composite (Al6061-B4C) Fabricated by Stir Casting Process

Abstract

Mechanical properties of Al6061-B4C composites fabricated by stir casting method, even though over 120 µm B4C reinforcement was used, was evaluated. The big reinforcement also could exert an impact on mechanical properties such as hardness and wear resistance. The presence of the harder particles dispersed in Al6061 increased hardness, which would in turn affect wear performance. The high hardness reduced the contact area between the sample and ball and thus, leaded to the reduced coefficient of friction (COF) and wear loss. The Al6061-12 wt.% B4C composite showed the best wear resistance, resulting in the narrowest and shallowest scar. The higher hardness of the Al6061-12 wt.% B4C composite changed wear mechanism changed from adhesive to abrasive wear so that the best wear resistance could be achieved.