Sintering of Vitrified Bond CBN Grinding Tool

摘要

Cubic boron nitride(CBN) is a superhard materials with many advantages and many uses. Vitrified bond CBN grinding tool is a promising abrasive tool of high performance used for high speed, high efficiency, high precision grinding with lower grinding cost and less environment pollution. Sintering of vitrified bond CBN grinding tool was investigated in this paper. The results showed that practical sintering temperature of this tool was much lower than the initial oxidation temperature of CBN particle measured by comprehensive thermal analysis. The upper limit of sintering temperature should be determined by taking account of the thermal analyzing results, heating process of CBN and its change in strength and structure. Within the sintering temperature range of the vitrified bond, relatively higher sintering temperature was beneficial to the strength of bond bridge and the holding strength between bond and CBN abrasive particles. CBN tool sintered at relatively lower temperature tended to fracture through the bond bridge, while the one sintered at higher temperature tended to fracture along the boundary between CBN abrasive grain and vitrified bond.