界面改性对SiC/Al双连通复合材料力学性能的影响

The novel co-continuous SiC/Al composites were prepared by a vacuum-infiltration technique. The effects of strain rates and surface oxidation modification of 3D-SiC preforms on the mechanical properties of co-continuous SiC/Al composites were investigated. The results show that the strain rate hardening effect of the co-continuous SiC/Al composites is obvious, and there is the maximum increment of 25% in compressive strength at strain rate from 10^-3 s^-1 to 10 s^-1. Furthermore, the compressive strength of the SiC_3D/Al composites are also improved by surface oxidation modification of SiC preforms, and the maximum increment is observed in the composite with 3D-SiC preform at 1200 ℃ for 6 h. Its compressive strength is about 10% higher than that of the SiC_3D/Al composite without surface oxidation modification at 10^-3 s^-1, which suggests that the surface oxidization modification for SiC preforms can play an important role in the fracture behaviours of the SiC_3D/Al composites due to the improvement of SiC/Al interfacial characteristics. But the three-point bending strengths of SiC_3D/Al composites are not sensitive to surface oxidization modification.