Effect of physical tempering on the mechanical properties of aluminosilicate glass

Research on factors that influence the physical tempering of glass is important for further exploration of the toughening mechanism and the development of new toughened glasses. In this study, the glass properties, viz., the elastic modulus and linear thermal expansion coefficient of aluminosilicate glass, were found to have a positive linear relationship with tempered strength. When the linear thermal expansion coefficient was (50 +/- 2) x 10(-7)/K, the average bending strength of the tempered aluminosilicate glass with a high elastic modulus increased from 88 to 305 MPa, which was 2.5 times higher than that of the annealed glass. When the elastic modulus was (85 +/- 1) GPa, from 73 MPa to 272 MPa, the average bending strength of the tempered glass with a high linear thermal expansion coefficient increased to 2.7 times that of the annealed glass. By optimising the tempering process of the glass specimen with an elastic modulus of 85 GPa and linear thermal expansion coefficient of 48.2 x 10(-7)/K, the average bending strength was improved by a maximum of 1.5 times. Moreover, a positive linear relationship was found between the surface compressive stress and tempered strength.