Effect of Li<sub>2</sub>O, K<sub>2</sub>O and ZnO on Vitrified Bond Composites for CBN Grinding Wheels

To investigate the effect of Li 2 O, K 2 O and ZnO on SiO 2 -Al 2 O 3 -B 2 O 3 -Na 2 O vitrified bond for CBN grinding wheels, the refractoriness and fluidity of specimens with different additions were studied. The bending strength was measured by three-point bending tester and the microstructures were observed by super Depth-of-Field microscope. The results show that Li 2 O, K 2 O and ZnO can reduce the refractoriness and increase the high-temperature fluidity. Li 2 O and K 2 O make a contribution to improving the bending strength; however ZnO is harmful to specimens’ mechanical property. Additionally, the fluidity is important to control the number of gas bubbles in specimen according to the microstructure analysis.