Properties of Al-based Matrix and Diamond Composites Fabricated by Semi-solid Metal Processing

In this paper, semi-solid metal (SSM) processing was first applied to fabricate Al-based matrix and diamond composites. A kind of Al-Cu alloy with an adequate solidification range was chosen. Samples of Al-Cu alloys were fabricated by rheocasting with different processing parameters. Specimens of Al-based matrix and diamond composites were fabricated by rheocasting and hot press sintering technology respectively. Microstructures, transverse rupture strength (TRS), hardness and wear resistance were studied. Experimental results revealed that the TRS of the Al-based matrix and diamond composites fabricated by rheocasting increased by 157% and 115% respectively compared to the ones fabricated by hot press sintering technology. The fracture surfaces of the rheocasting specimens exhibited ductile cup and cone behavior as well as strong bonding between the matrix and diamond grits.