对立方氮化硼(CBN)磨粒和聚酰亚胺(PI)树脂进行热压固化成型和后续热处理,制备了M树脂/CBN砂轮,用热重一差示扫描量热分析仪、红外光谱仪、扫描电子显微镜、磨削试验设备及力学性能试验机等研究了PI树脂的固化反应机理、PI树脂/CBN砂轮的制备工艺及磨削性能。结果表明:试验所用PI树脂的固化反应存在线型与体型聚合两个固化反应放热峰,峰值分别在140℃与235℃;PI树脂/CBN砂轮能够精密磨削淬火45钢,磨削后表面粗糙度达到O.19μm,磨削比为775,在相同磨削条件下比酚醛树脂/CBN砂轮的耐用性更佳。
A polyimide resin (PI) bonded cubic boron nitride (CBN) abrasive grain grinding wheel was prepared by hot-pressing curing and forming and subsequent thermal treatment. The PI resin curing mechanism, the manufacturing process and grinding performance of the PI resin/CBN wheel were investigated by differential scanning calorimeter and thermogravimetry analysis, infrared spectroscopy, scanning electron microscopy, mechanical property test and grinding experiments. Results show that there were two exothermic peaks of 140 ℃ and gas ℃corresponding to chain and a cross-linking polymerization reaction, respectively in the PI resin curing process. Surface roughness of 0. 19/,m and grinding ratio of 775 were obtained when the PI resin bonded CBN wheel grinded the hardened steel 45. The PI resin bonded CBN wheel exhibited better durability than the phenolic resin bonded CBN grinding wheel under the same grinding condition.