Enhanced mechanical properties in Al/diamond composites by Si addition

Diamond particles reinforced aluminum–silicon matrix composites, abbreviated as Al(Si)/diamond composites, were fabricated by squeeze casting. The effect of Si content on the microstructure and mechanical properties of the composites were investigated. The mechanical properties are found to increase monotonically with Si content increasing up to 7.0 wt%. The Al-7.0 wt% Si/diamond composite exhibits tensile strength of 78 MPa, bending strength of 230 MPa, and compressive strength of 426 MPa. Al–Si eutectic phases are shown to connect with Al matrix and diamond particles tightly, which is responsible for the enhancement of mechanical properties in the Al(Si)/diamond composites.