Abstract:SiC_p/5210 Al metal matrix composites with a high volume fraction (50%) of SiC particles were fabricated by squeeze casting method. The effect of particle size on the mechanical properties of the composites was studied. The results show that with the decreasing of particle size, the bending strength of the composites increases, while the fracture toughness of the composites decreases. The bending strength and fracture toughness of 10 μm SiC_p/5210 Al metal matrix composite are 825 MPa, 10.0 MPa∙m^1/2, and the fracture toughness of 63 μm SiC_p/5210 Al metal matrix composite reaches 12.8 MPa·m^1/2. The main fracture mechanism changes from particle crack to particle/matrix interface de-bonding with the decreasing of particle size.

Key words: metal matrix composite; SiC_p/5210 composite; squeeze casting; mechanical properties