Effect of ZrO2 on crystallization behavior and mechanical property of Dy2O3–Al2O3–SiO2 glasses

Abstract

Effects of ZrO2 content on the crystallization kinetics, formation mechanism of voids and mechanical property of Dy2O3–Al2O3–SiO2 glass were studied. The crystallization method of DAS glasses transforms from surface crystallization into bulk crystallization with an increase in ZrO2 content from 0-3% to 6–9%. When ZrO2 content is 0–3%, the crystalline phases of DAS glass ceramics are Dy2Si2O7 and Al2O3, accompanied by formation of voids. When ZrO2 content is 6–9%, the DAS glass ceramics consist of Dy2Si2O7, Al2O3 and ZrO2. At the same time, no voids are found in the glass ceramics. Therefore, formation of voids during crystallization can be attributed to combined effect of the crystallization method and the density difference before and after crystallization. In addition, for glassy samples, the flexural strength increases from 80.4 MPa to 219.3 MPa with an increase in ZrO2 content from 0% to 9%. Moreover, crystallization further improves the mechanical properties of the DAS glass ceramics with bulk crystallization method.