Microstructure and Properties of Gradient SiC_P/Al Composites

SiC_P/Al composites with SiC content gradient were prepared by liquid hot pressing after layered powder loading, and its microstructure and properties were studied. The results show that the SiC particles were evenly distributed in each layer of the gradient SiC_P/Al composites, the interface of each layer of the gradient SiC_P/Al composites was clear and straight, the interface bonding was good. In the process of simultaneous densification of each layer mixture under pressure, the liquid aluminum alloy in the top layer penetrated into the transition layer, and the liquid aluminum in the transition layer also penetrated into the bottom layer, resulted in the increase of SiC content in the transition layer. Finally, the thermal expansion coefficient of the gradient SiC_P/Al composites increases from 21.0×10^-6 ℃^-1 of the top layer to 8.0×10^-6 ℃^-1 of the bottom layer. The flexural strength of the gradient SiC_P/Al composites increase with the increase of the volume fraction of SiC particles, and the increase between the bottom layer and the transition layer was small.