Influence of heat treatment on the wear behavior of an Al-Cu-Mg-Sn MMC reinforced with TiB2

The need to reduce emissions has pushed the automotive industry toward the introduction of light-weight components, which has increased the interest in metal matrix composites (MMC) based on light alloys in applications where the strength-to-weight ratio, hardness and wear resistance are important. Age hardenable aluminum alloys reinforced with ceramic particles can meet these needs. This study analyses the influence of solution heat treatment and age hardening on the wear rate and friction coefficient of an Al-Cu-Mg-Sn alloy reinforced with TiB 2 under sliding contact conditions against spheres of Si 3 N 4 and AISI 52100 Steel. The experiments show that adhesion is the main wear mechanism, with abrasion as a significant secondary effect. The presence of TiB 2 particles in combination with the ageing treatment contribute to the reduction of both friction coefficient and wear when compared with the same aluminum alloy without ceramic particles. The results are explained as a function of the hardness increase and the tribological compatibility between the alloy and contacting spheres. On a microstructural level, the severe plastic deformation associated to sliding wear is clearly observed. Dissolution of intermetallic particles is complete in the tribolayer and grain refinement is much stronger than what is observed in single-phase alloys.