关键词: 堇青石, 多孔陶瓷, 烧结助剂, 氧化锆, 氧化镧

Abstract: To achieve the low temperature synthesis of cordierite,according to its theoretical ratio,porous cordierite ceramics were prepared using calcined kaolin (≤0.044 mm),sintered magnesia (≤0.074 mm) and silica micropowder (d₅₀=2.6 μm) as main raw materials,analytically pure zirconia and lanthana as sintering aids,and polyvinyl alcohol (PVA) solution as the binder,pressing to samples of 30 mm×30 mm at 60 MPa,drying and calcining.The effects of the extra additions of zirconia (0 and 8%,by mass) and lanthana (0,0.2%,0.4%,0.6% and 0.8%,by mass) and calcination temperatures (1 200,1 250 and 1 300 ℃) on the cold physical properties,phase composition and microstructure of the porous cordierite ceramics were studied.The results show that:(1)the sample fired at 1 300 ℃ and introduced with 8% zirconia and 0.6% lanthana shows good physical properties;(2)the co-doping of zirconia and lanthana can improve the mechanical properties of the sample while maintaining the apparent porosity,and promote the formation of cordierite;(3)the co-doping of zirconia and lanthana can reduce the synthesis temperature of cordierite and improve the comprehensive performance of the sample.

Key words: cordierite, porous ceramics, sintering aid, zirconia, lanthana