Study on Sintering Properties of Al₂O₃-70 Natural Mullite by New Processes

Abstract

This paper explains sintering properties of Al2O3-70(referred to as the 70 green sample) natural mullite that was prepared by the process of homogenization, wet grinding, vacuum extrusion and high-temperature tunnel kiln sintering. The results show that 70 green sample's dehydroxylation temperature started in 528 °C; 70 green sample's sintering densification started in 1500 °C; 70 green sample had not completed sintering in the 1600 °C, and at this temperature, to prolong the holding time also won't realize densification. After sintering at 1600 °C, the sample's bulk density is 2.82. In this sample, the mullite phase was uniform distribution, density, low porosity and most are closed porosity.