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 mu m and 93 mu m) 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 mu m) exhibited higher hardness than that reinforced with coarser TiC (0.8-5.6 mu m) particles. However, the detachment of carbide particles from wear surfaces of the composite reinforced with TiC particles (0.6-3.5 mu m) results in the deterioration of its wear resistance. (C) 2011 Elsevier Ltd. All rights reserved.