Sinterability of ZrSiO4/α-Al2O3 mixed powders

The sinterability of ZrSiO4/α-Al2O3 mixed powders with three different compositions was investigated with respect to phase development during firing. The study reveals that the 65/35 sample (low-Al2O3) has good sinterability below the temperature of 1450 °C because it contains more easily sintered ZrSiO4/α-Al2O3 particle interfaces. With increasing temperature and the reaction proceeding, ZrSiO4/α-Al2O3 particle interfaces disappeared and the sinterability of samples was changed greatly by the phase developments. As a result, the 80/20 sample (high-Al2O3) became more sinterable at high temperatures. SEM observations show a smaller ZrO2 grain size in the 80/20 sample than in the 65/35 sample, because ZrO2 grain growth in the 80/20 sample involved longer diffusion paths.