A novel low-clay translucent whiteware based on anorthite

Abstract

This study was carried out to characterize the properties of a novel low-clay translucent whiteware suitable for daily use. The low-clay whiteware is produced from coarsely and finely milled prefired materials of the same composition plus a small amount of clay. It consists of anorthite (CaO center dot Al2O3 center dot 2SiO(2)) and mullite (3Al(2)O(3)center dot 2SiO(2)) crystalline phases and a glassy phase with high crystalline to glassy phase ratio. The development of needle shaped long mullite crystals that were forming three dimensional interlocking network had significant effect on the elimination of pyroplastic deformation during glaze firing. Typical flexural strength and fracture toughness values were similar to 110 MPa and similar to 1.85 MPam(1/2), respectively. The low-clay whiteware had relatively low (4.6 x 10(-6)/degrees C) thermal expansion coefficient which made possible to glaze the whiteware with a typical hard porcelain glaze. A continuous interface layer was produced between the whiteware and the glaze and no crack was present through layer because of expansion mismatch. (C) 2010 Elsevier Ltd. All rights reserved.