Abstract
Using Mg-α SiAlON powder synthesized by carbothermal reduction-nitridation, fabrication of Mg-α SiAlON ceramics was attempted through gas pressure sintering method. The effects of firing temperatures and sintering aids on the density and phases of sintered bodies were investigated. As a result, in the case of no addition of sintering aid, phase transformation to β-SiAlON was enhanced with elevating temperatures. Furthermore, it was found that dense Mg-α SiAlON sintered body could be obtained by addition of α-Si3N4, whereas β-SiAlON, SiC, 15R and AlN, which existed in as-synthesized powders, completely diminished after high temperature firing. The dense Mg-α SiAlON ceramics composed of fine and uniform grains could be obtained with 5wt% α-Si3N4 additive through firing at the temperature of 1950°C for 2 hours.
