HE Yongtao¹, XIAO Zhuohao¹, LI Xiuying¹, XIAO Xiaodong¹, YI Chenhao², KONG Lingbing¹

(1. Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China; 2. Jiangxi Guanyi Abrasives Co., Ltd., Fengxin 330700, Jiangxi, China)

Abstract: K₂O-Na₂O-CaO-B₂O₃-SiO₂ glass was prepared by traditional melt cooling method, effects of different B₂O₃ content on thermal expansion and bending strength of glass were investigated. The glass with optimum composition is used as bonding agent for corundum grinding wheel. The effects of different sintering temperatureand holding time of grinding wheel on  micro-structure, phasecomposition, bending strength and porosity of grinding wheel were studied. The results show that the bending strength of glass presents “abnormal boron phenomenon” with the increase of B₂O₃ content. When the content of B₂O₃ is 9wt.%, a glass with flexural strength of 119.51 MPa and thermal expansion coefficient matching that of corundum can be obtained. With the increasing of the sintering temperature and holding time of the grinding wheel, the bending strength of the grinding wheel increases first and then decreases. After holding for 4 hours at 1000 °C, the bending strength of the grinding wheel specimen reaches 100.96 MPa. XRD test shows that glass binder exists stably in amorphous state during grinding wheel sintering. SEM shows that the exfoliation of corundum abrasive particles is mainly due to the interface separation between abrasive and binder.
Key words: glass binder; B₂O₃; sintering process; corundum grinding wheel