Alumina lightweight ceramics modified with plasma synthesized nanopowders

Abstract

The aim of this study is to clarify possibilities of using plasma synthesized Al 2O 3 and SiC nanopowders as additives in alumina lightweight ceramics prepared by slip casting. Each plasma synthesized nanopowder (PSNP) was incorporated in the material by a different method, because of their diverse influence on the properties of slip. Al 2O 3 PSNP was introduced in the matrix in form of aqueous suspension. SiC nanopowder was added directly to raw materials. Bending strength, bulk density, apparent porosity and thermal shock resistance were determined to evaluate the influence of these additives. The effect of Al 2O 3 PSNP addition on the properties of material depends on the initial sintering temperature. SiC particles during sintering oxidize into SiO 2 and then in the reaction with alumina form mullite. Addition of SiC considerably improves bending strength and thermal shock resistance.