EFFECT OF NANO-SiC ADDITION ON THE PROPERTIES OF Si3N4 (SHS)/SiC (NANO) COMPOSITES

摘要

Powder mixtures of Self-propagating Combustion Synthesis β-SiC and Si3N4 with low a phase (α,β = 60:40) were liquid-phase sintered using AlN-Y2O3-La2O3 as sintering additives. The effects of β-SiC content changed from 5% to 30% on the microstructure and the mechanical properties of the composites were studied. The result showed that the densities of the samples with SiC content from 10 to 25 wt% all reached ～99% TD. Of them the sample with SiC content of 10% is the optimum, otherwise that of 30% is the worst. The weight loss and the shrinkage of the samples decreased with increasing SiC content. The morphology of the samples and the distribution of SiC in the composite were studied by using SEM, EDX and XRD. The influence of SiC content on the microstructure and the mechanical properties of specimens were discussed.