Production and characterisation of silicon carbide particulate reinforced aluminium–copper alloy matrix composites by direct squeeze casting method

In this study, the effects of volume fraction of SiC on microstructure, hardness and tensile properties as well as density have been investigated in Al–4.5Cu–3Mg matrix alloy and its 5, 10, and 15 vol.% SiC particle reinforced composites. The results showed that squeeze casting resulted in refining microstructure, porosity and other casting defects such as shrinkage cavities were minimised due to pressure application during solidification. Hardness and tensile properties of matrix alloy were increased by squeeze casting. In composites, hardness increased with increasing volume fraction of SiC. Increasing volume fraction of particles caused to increase porosity and to decrease the elongation and reduction in area. Fracture surface analysis showed that, the failure in composites occurs in both the matrix and particles simultaneously. Furthermore, this indicated that there is a good bonding between matrix and SiC particles and the fracture initiation did not occur at matrix particle interface.