Slip Casting of a-Siafon/AlN/BN Powder Carbothermally Prepared by Boron-rich Slag-based Mixture

摘要

With boron-rich slag, silica fume, bauxite chalmette and carbon black as starting materials, a-sialon/AlN/BN powder was prepared by carbothermal reduction-nitridation. The powder was attrition milled to submicron size and suspended in water. The effects of yttrium oxide as a sintering aid, pH, and addition of defiocculant on the suspensions were studied. Optimum slip casting properties, i.e. lowest viscosity values, the highest absolute zeta potential values, the smallest floe size and sediment volume were found at pH=10 for the powder.