Abstract
SiC powders with five different particle sizes were sintered without any additives at temperatures from 1600 to 1800℃ by using a spark plasma sintering (SPS) apparatus. The relative density, bending strength and microstructure were evaluated to investigate the effects of particle size on the properties of SiC compacts. Density analysis results showed that fine 0.34 SiC powders are favorite for sintering higher relative density SiC compact. Bending strength analysis results showed that with decreasing the particle size the bending strength of sintered compacts increased obviously. Composition analysis indicated that the carbon composition at grain boundary was higher than that at matrix for the compacts sintered with 2.4 and 30μm SiC powders. It might suggest that carbon segregation at grain boundaries might favorite the combination of the SiC particles though no extra carbon was added to the starting powders.
