| Abstract |
This study examined the sintening parametrers on the microstructure and mechanical properties of vitrified bond diamond tools. The composites composed of borosilicate glass and diamond grits were sintered at 690¢J, 710 ¢J, 730¢J for 60 min, 90 min or 120 min, respectively. The thermal analysis, X-ray diffraction analysis, X-ray photoelectron spectroscopy, and Raman spectra were analyzed for the specimens to investigate the degree of degradation of the diamond crystal and chemical bonding between the diamond grits and the borosilicate glass. The shrinkage percentage, hardness, grinding ratio, and surface roughness against a cemented carbide work piece were examined along with microstructural analysis based on secondary electron images. XPS analysis showed that increasing the sintering temperature resulted in increase in the intensity of N-C and N¡ÝC , but decrease in N-B bonds. The bond hardness and shrinkage percentage closely maintained linear relationships with the isothermal holding time at a sintering temperature of 690¢J and 710¢J. In the range of the sintering temperature and isothermal holding time investigated in this study, sintering temperature had a greater influence on the wheel¡¦s grinding performance than isothermal holding time. The hardness of the bonds of composites sintered at 730¢J for 120 minutes had highest average hardness (mHV 611) than the other specimens. The grinding ratio test results indicated a lower grinding ratio for the 690-60 specimen, and the highest grinding ratio for the 710-90 specimen. A sintering temperature of 710 ¢XC and an isothermal hold of 90 min were found to be optimal in achieving an optimal combination of bond strength and grinding performance. |
