Effect of TiO2 addition and high magnetic field sintering on properties of vitrified bond CBN composites

Vitrified bond CBN composites, with different amounts of TiO2 doping, were prepared by conventional sintering and high magnetic field sintering processes. Mechanical properties, cross-sectional morphology, refractoriness, fluidity and structural characterization have been carried out to understand the role of TiO2 addition and sintering conditions. Results show that TiO2 addition significantly affected bending strength, refractoriness and fluidity of vitrified bonds. In addition, high magnetic field sintering improved bending strength and the microstructure of vitrified bond CBN composites. Due to high magnetic field sintering, CBN grains were completely covered by vitrified bond and exhibited fewer pores. In addition, high magnetic field promoted the growth of specific grains, such as SiO2, whereas suppressed grain growth of other crystal phases, such as NaAlSi3O8.