关键词: MgO, 纳米氧化铝, 陶瓷过滤器, 室温压缩强度

Abstract: To improve their mechanical properties,MgO ceramic filters with porous skeleton structures were prepared by the organic foam impregnation method using microporous MgO powder as the raw material.The effects of the second-phase nano-alumina additions (0,3%,6%,9%,and 12%,by mass) and heat treatment temperatures (1 450,1 500,1 550,and 1 600 ℃) on the physical properties,phase composition,microstructure and mechanical properties of the ceramic filters were investigated.The results show that:the introduction of nano-alumina leads to the in-situ formation of magnesium aluminate spinel among the grains,which improves the grain bonding strength,reduces the apparent porosity,increases the bulk density and improves the cold compressive strength.However,when the nano-alumina addition exceeds 6%,excessive spinel among the grains hinders the direct bonding of MgO grains,thus reducing the cold compressive strength.The raise in the heat treatment temperature increases the solid solubility of Al₂O₃ in MgO,thereby promoting sintering,increasing the relative density,and enhancing the cold compressive strength.With the nano-alumina addition of 6% and heat treatment temperature of 1 600 ℃,the filter exhibits the maximum cold compressive strength of 1.42 MPa,the apparent porosity of 81.5%,and the bulk density of 0.66 g·cm^-3.

Key words: MgO, nano-alumina, ceramic filters, cold compressive strength