Optimization of SiCp Surface and Interface Structure of SiCp/A390 Composites

SiCp/A390 (SiC particle reinforced Al matrix) composites before and after SiC particles surface modification were manufactured respectively by powder metallurgy, and the mass fraction of SiCp is 20%. The surface morphology of SiCp and the interface morphology of SiC/Al and SiC/Si of composites were characterized by TEM. The chemical state of interface material of SiCp/A390 composites was tested by XPS. The effect of surface modification of SiCp on interface structure of composites and thermodynamic principle of mechanism of interface formation of SiCp/A390 were researched. The results show that SiCp morphology was changed though surface optimization treatment, the dense SiO2 oxide layer on the surface of SiCp was formed when SiC particles were roasted at 1000 degrees C, which thickness membrane is about 50 nm. Before SiC particles surface modification, the interface of SiC/Al of composites is clear, clean interface, and discovered a small amount of amorphous layer interface of SiC/Al. While, after SiC optimization, the interface of SiC/Al of composites is an amorphous layer between two phases, and there is no Al4C3 in SiCp/A390 composites. Surface modification treatment of SiCp can increase chemical reaction degree of the interface of composites, and effectively improve the interface bonding of SiC and Al.