Effect of alloying elements on mechanical properties of the SiC/Al biconnected composites

SiC_3D/ZL201A biconnected composite was prepared with vacuum pressure infiltration. The effect of alloying elements on its microstructure and mechanical properties was studied by means of scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The results show that the aggregation of elements such as Cu and Mg at the interface of SiC_3D/ZL201A exists, and the microstructure at the interface is improved. The alloying elements lead to the higher compressive strength and lower bending strength of SiC_3D/ZL201A than those of SiC_3D/pure aluminum. The failure of SiC_3D/ZL201A is interfacial fracture, i.e., SiC skeleton performs brittle fracture and the aluminum alloy matrix shows ductile tearing fracture. The alloying elements improve the mechanical properties of the composite by passivating the cracks, changing the direction of crack propagation and bridging.