关键词: MgAl₂O₄多孔陶瓷, 热处理温度, TiO₂, 显气孔率, 显微结构

Abstract: To solve the problem of property decline caused by the volume expansion during the preparation of porous MgAl₂O₄ ceramics by solid phase sintering method,porous MgAl₂O₄ ceramics were prepared via the dry pressing-solid phase reaction route using Al₂O₃ (d₅₀=1.1 μm) and MgO (d₅₀=1.5 μm) as the main raw materials and TiO₂ (d₅₀=1.5 μm) as the additive.Influences of hot treatment temperatures (1 300,1 350,1 400,1 450,and 1 500 ℃) and TiO₂ additions ( 0,0.5%,1.0%,1.5%,and 2.0%,by mass) on the linear change rate on heating,apparent porosity,bulk density,phase composition and microstructure of the porous MgAl₂O₄ ceramics were investigated.The experimental results show that:(1)as the hot treatment temperature increases,the densification of the porous ceramics increases,the bulk density increases but the apparent porosity decreases;(2)as the TiO₂ addition increases,the linear shrinkage rate on heating of the porous ceramics increases,the apparent porosity decreases remarkably,while the average grain size increases.

Key words: porous MgAl₂O₄ ceramics, hot treatment temperature, TiO₂, apparent porosity, microstructure