Comparative processing-structure–property studies of Al–Cu matrix composites reinforced with TiC particulates

Effects of TiC content and size on the microstructure, density, hardness and wear resistance of Al–4 wt.% Cu matrix composites were investigated. Al–4 wt.% Cu matrix composites were fabricated using two main processing routes of powder metallurgy (PM) and casting. In the PM process, Al–4 wt.% Cu matrix alloy reinforced with 10 wt.% TiC particulates of two different average sizes (13 μm and 93 μm) were mechanically alloyed and sintered. In the second process, Al–4 wt.% Cu–xTiC (x = 5, 10, 15 and 20 vol.%) composites were fabricated using a flux-assisted casting. Both the wear resistance and the hardness of cast composites improved with TiC content. The sintered composite containing smaller TiC particles (0.6–3.5 μm) exhibited higher hardness than that reinforced with coarser TiC (0.8–5.6 μm) particles. However, the detachment of carbide particles from wear surfaces of the composite reinforced with TiC particles (0.6–3.5 μm) results in the deterioration of its wear resistance.