Effects Of Additives On The Microstructure And Properties Of Mullite/Corundum Kiln Furniture

High temperature Mullite/Corundum kiln furniture was produced by mullite and corundum. The material have high using temperature(>1350℃), high temperature strength, chemical stability and good compatibility with product. It is deemed to be one of the most widely used high -temperature kiln materials. It is specially used to product mild magnet (ferrite) and electronic isolated ceramic. But the thermal shock resistance of this kiln furniture is low. Increasing the thermal shock resistance often result in high temperature strength decreasing. There exists a conflict between thermal shock resistance and high temperature strength of kiln furniture. In present work, we attempt to change the microstructure and properties of mullite-corundum kiln furniture by introducing additives and hope that thermal shock resistance and high temperature strength of kiln furniture were improved simultaneously.Effects of the content and particle size of zircon, the content and particle size of ATM and TiO2 content on the microstructure and properties of mullite-corundum kiln furniture were investigated. The main conclusions as fellows:1. The microstructure and properties of mullite-corundum kiln furniture can be adjusted by the addition of zircon. The thermal shock resistance and high temperature flexural properties can be greatly increased when the amount and particle size of zircon are suitable. When the sintering temperature is 1550℃, the kiln furniture's thermal shock resistance was significantly increased. When the sintering temperature is 1650℃, the high-temperature bending strength was increased remarkably. The zircon powder with smaller particle size can be introduced to improve thermal shock resistance of the specimen. The zircon powder with larger particle size is good to improve the room temperature strength and high temperature strength of samples.2. The thermal shock resistance and high temperature flexural properties can be greatly increased when the amount and particle size of ATM are suitable. When the sintering temperature is 1550℃, the kiln furniture's thermal shock resistance is increased and when the sintering temperature is 1650℃, the high-temperature flexual strength increased obviously.3. Titanium dioxide particles can improve the performance of the samples, but the effect is not obvious.4. The addition of micro silica in the matrix of samples can significantly improve the thermal shock resistance and high temperature strength of samples.