Oxidization of diamond grits in diamond/borosilicate glass composites

Abstract

The oxidation reaction mechanism of diamond grits in diamond/borosilicate glass composites was studied. The composites were sintered at different conditions and the samples were analyzed through TG–DSC, XRD and Raman. The results showed no chemical reaction occurred when borosilicate glass was sintered below 1000 ℃. But when sintering diamond/borosilicate glass composites at temperatures above 814 ℃, there appeared volume expansion and bending strength decreasing. The volume expansion is 10% and the bending strength is 39.0 MPa when the composites are sintered at 780 ℃. Through thermodynamic analysis, XDR analysis and Raman analysis, it is found that when the sintering temperature is lower than 908.4 ℃, the diamond is oxidized by the free oxygen other than the oxides in the glass.

Keywords

• borosilicate glass
• diamond
• oxidation reaction mechanism