Effect of cobalt on properties of vitrified bond and vitrified cubic boron nitride composites

Properties of vitrified bonds and vitrified cubic boron nitride (CBN) composites containing varying amounts of doped cobalt (Co) were comprehensively investigated. Their fluidity, refractoriness, coefficient of thermal expansion (CTE), porosity, cross-sectional morphology, and mechanical properties were characterized by various techniques. Furthermore, thermogravimetric/differential scanning calorimetry curves were obtained to investigate the role of Co content. Results showed that the CTE of vitrified bond increased due to the presence of Co. Moreover, the glass transition temperature of vitrified bond was also reduced by adding Co. In the presence of appropriate amount of Co (10.8 wt%) in vitrified bond, its fluidity and refractoriness were slightly increased, and bending strength of vitrified bond and vitrified CBN composites was enhanced. Vitrified bond and vitrified CBN composites with optimal content of added Co exhibited cross-sectional structure with uniform pore size and homogeneous pore distribution.