Investigation of multi-phase intermetallic matrix composites (IMC) based on Al–Mo–Zr–Co system

The processing, microstructures and mechanical properties of intermetallic alloy based on Al–Mo–Zr–Co (AMZC) and its composites reinforced with micro-sized TiC, partially stabilized zirconia (PSZ)-ZrO2 or SiC particulates were investigated. The results showed that the alloy system exhibits multi-phase microstructures, composed of several aluminides including ZrAl2, Al5Co2, Al9Co2, AlMo3, Al8Mo3 and Zr2Al. The AMZC/SiC composite showed poor mechanical properties, due to the existence of residual porosity and weak interfacial bonding. In contrast, the other two composites exhibited superiority in both flexural strength and fracture toughness at room temperature than the Al–Mo–Zr–Co-based multi-phase alloy. Homogeneous distribution of ceramic particles and perfect interfacial bonding accounted for the improvement of strength. The addition of TiC or ZrO2 particle into the matrix alloy produced remarkable toughening effect.