Optimized structural and mechanical properties of borophosphate glass.

A series of phosphate glasses composed of (65-x)P 2 O 5 –15BaO–5Al 2 O 3 –5ZnO–10Na 2 O-xB 2 O 3 (x = 0, 2, 4, 6, and 8 mol%) were successfully prepared using the melt-quenching method. The effects of the addition of boron trioxide (B 2 O 3) on the physical, structural, and mechanical properties of the glasses were investigated. As the added content of B 2 O 3 increased from 0 to 6 mol%, the glass exhibited increased density and transition temperature, and decreased molar volume, indicating optimization of the glass stability. Raman spectroscopy revealed that the introduction of B 2 O 3 transformed the glass from a chain structure to a three-dimensional network structure, which enhanced the chemical stability of the glass by the cross-linking of long phosphate chains with boron ions. Regarding the mechanical properties, when the boron content was 6 mol%, the flexural strength of the glass was 41% higher than that of the undoped boron, while the Vickers hardness and Knoop hardness values increased by 20.58% and 7.05%, respectively, and the fracture toughness was slightly decreased. In general, improving the mechanical properties of phosphate glass is of great significance for increasing the applications of this glass. [ABSTRACT FROM AUTHOR]