Influence of Surface Treatment of CBN Grits on the Properties of B-Si-Na Vitrified Abrasive Tools

摘要

In this paper, by using scanning electron microscopy (SEM) and element dispersive spectrum (EDS) together with three-point bending test, the influence of different surface treatment of cubic nitride boron (cBN) on the bonding of cBN with B-Si-Na vitrified bond had been studied. The results showed that cBN coated with corundum could greatly improve the specimen's bending strength and grinding properties. SEM analysis showed that the interface between cBN grits and vitrified bond was a perfect indention combination. On the other hand, when uncoated cBN was used in abrasive tool, the specimen's bending strength dropped down seriously. The reason was that many cavities produced at the interface between cBN grits and vitrified bond, decreasing the actual area of load, due to the corrosion reaction between cBN grits and vitrified bond components during sintering. EDS analysis also showed that corundum-coated cBN could form components gradient change from cBN grits to vitrified bond during sintering and made the abrasives bond vitrified substrate compatibly.