醇-水基料浆凝胶注模成形制备氧化铝多孔陶瓷

Porous alumina ceramics prepared by alcohol-water based gel casting process

以氧化铝粉为原料,乙醇–水为溶剂,采用凝胶注模成形工艺制备氧化铝多孔陶瓷,并研究溶剂中醇、水体积比对多孔陶瓷坯体和烧结体的收缩率、孔隙度、微观形貌及性能的影响。结果表明:多孔陶瓷的孔隙由溶剂挥发形成的"溶剂孔"和高聚物分解形成的"高聚物孔"两部分组成,孔隙呈三维贯通孔结构。当醇、水体积比由3:7增加至9:1时,制品线收缩率与抗弯强度逐渐减小,孔隙度和气体渗透通量逐渐增加。当醇、水体积比为7:3时,所制备的陶瓷具有优良的综合性能:孔隙率为76.91%,孔隙分布均匀,抗弯强度为13.08 MPa,气体渗透通量达到135.6 m3/(m2·h·kPa)。

Using high purity alumina powder as raw material, alcohol-water mixture as solvent, porous alumina ceramics were fabricated by alcohol-water based gel casting process. The effect of alcohol-water solvent ratio on the shrinking percentage, porosity, microstructure, properties of porous alumina green body and sintered ceramics were investigated. Both evaporation of solvent and decomposition of polymer contribute to the porous microstructure of the as-prepared green body and sintered ceramics, which features three dimensional inter-connected pores. With increasing the alcohol-water ratio from 3：7 to 9：1, the line shrinking percentage and flexural strength decrease, porosity and air permeability increase. When alcohol-water ratio is 7：3, optimal comprehensive performances, including uniformly distributed pores with porosity of 76.91%, flexural strength of 13.08 MPa and air permeability of 135.6 m3/（m2？h？kPa）, can be obtained.