Minimization of water absorption and pyroplastic deformation of wollastonite-containing alumina-strengthened porcelain

Abstract

The densification and pyroplastic deformation of alumina-strengthened porcelain were examined within a range of alumina and wollastonite contents. Both the alumina addition and anorthite crystallization not only prevent the liquid-phase sintering, which plays an important role in the densification of the porcelain during firing, but also suppress the pyroplastic deformation at high firing temperatures. The prevention of densification as well as the suppression of pyroplastic deformation is basically described by the change in the amount of liquid phase at firing. As a result, optimization between small water absorption and small pyroplastic deformation was found out in the relatively wide firing temperature range for porcelain with 30 mass% alumina addition and <10 mass% wollastonite addition. This study serves as a guide to achieve minimal water absorption and pyroplastic deformation in alumina-strengthened porcelain fired at temperatures from 1290 to 1380°C.

Keywords

• alumina-strengthened porcelain
• densification
• wollastonite
• anorthite
• pyroplastic deformation