Effect of Main Material Ratio on Properties of SiC-Al2O3 Porous Ceramics via Polymeric Replication Method

摘要

In order to fabricate porous ceramics with good properties and proper production cost,SiC-Al2O3 porous ceramics were prepared at 1 450 ℃ for 2 h from the powders of commercial silicon carbide and white fused corun-dum via a polymeric replication method.Effects of the mass ratio of SiC powder to white fused corundum powder (1 ∶ 3,1 ∶ 1 and 3 ∶ 1) on the appearance,phase composition,sintering properties and thermal shock resistance were investigated.The research results indicate that the as-prepared SiC-Al2O3 porous ceramics have uniform pores,and their linear shrinkage ratio,apparent porosity and bulk density reach 4.70％,67.17％ and 0.83 g · cm-3,respectively.The thermal shock cycles from 1 400 ℃ to room temperature reach 23 including 15 cycles in air cooling condition and then 8 cycles in water cooling condition.Their main phases are α-Al2O3 and Al6Si2O13 as well as a small amount of SiC and free SiO2.The as-prepared porous ceramic with the ratio of m (SiC) ∶ m (Al2O3) =1 ∶ 1 possesses prior comprehensive properties.