Effect of ZrO2 substitution for SiO2 on the structure and properties of high-alumina-silicate glasses

Abstract

High-alumina-silicate glasses with ZrO 2 substitution for SiO 2 were prepared by a conventional melt-quenching method to investigate the effects of ZrO 2 substitution on the structure, thermal properties, optical transmittance, microhardness, and chemical strengthening behavior of the SiO 2 –Al 2 O 3 –Na 2 O–K 2 O–MgO glass system. The results show that up to 4 mol% ZrO 2 substitution predominantly enhances the glass networks, while no obvious crystalline phase is detected by XRD. The ZrO 2 substitution could lead to a decrease in the fraction of low-polymerized Q 1 and Q 2 structural units and an increase in the fraction of highly polymerized Q 3 and Q 4 structural units, as well as an enhancement in structural compactness. The density, oxygen packing density, glass transition temperature ( T g ), and Vickers hardness of the glasses can be improved with the ZrO 2 substitution. Moreover, the measured optical transmittance of the investigated glasses is higher than 90% at 550 nm, and the surface compressive stress (CS) and Vickers hardness of the chemically strengthened glasses could reach 1030 MPa and 7.81 GPa respectively. The improved chemical strengthening and Vickers hardness are closely related to the enhanced network polymerization and structural compactness induced by the ZrO 2 substitution. The findings could provide a theoretical basis for designing and optimizing the composition and properties of chemically strengthened high-alumina-silicate glasses.