OPEN POROSITY AND STRENGTH CONTROLLING BY MEANS OF GRAIN COMPOSITION VARIATION FOR THE CERAMICS ON BASE OF FUSED-CAST CORUNDUM WITH PORCELAIN BINDER

Abstract

The tough porous ceramics samples on base of granular mixture of the fused-cast corundum with grain size of both 2‒3 and 0.5 mm (95 mass %) and porcelain binder (5 mass %) were investigated in the article. The granular mixture compositions have been prepared with various 2‒3 mm / 0,5 mm fraction ratios: 0/95, 35/60, 45/50, 50/45 and 95/0. The samples were compacted under the pressure 25, 50 and 100 MPa and fired at 1350 and 1450 °C. The sintered samples had ultimate bending strength between 19 and 143 MPa, and the open porosity between 17 and 26 %. The results are explained by the creation of a scaffold and the regions external to the scaffold in the half-finished material. The porous penetrable ceramics can be usable as ceramic filters and ceramic membrane supports.