针对航空航天高强韧性难加工材料TC4钛合金在磨削加工中存在磨削温度高而导致工件表面烧伤的问题,提出利用热管换热技术冷却磨削弧区的新方法。分析了环形热管砂轮在加工中对磨削弧区的强化换热原理,并设计制作出能够用于磨削加工的环形热管砂轮,同时实现了对砂轮基体内环形管腔的密封、抽真空、精确注液与机械式真空封口。最后,在相同磨削工艺条件下,使用环形热管砂轮和无热管砂轮进行TC4钛合金缓进给深切磨削对比试验,验证了环形热管砂轮对磨削弧区温度的控制效果。试验结果表明:设计制作的环形热管砂轮在TC4钛合金高效磨削过程中可以有效降低磨削温度,避免工件表面出现烧伤。
Workpiece burnout is one of the distressing problems to be solved for the difficult-to-machine material TC4 titanium alloy due to the high grinding temperature caused by excessive grinding heat accumulation in the grinding zone.A new method of cooling the grinding zone by means of heat pipe technology is proposed in this paper.The heat transfer principle of an annular heat pipe grinding wheel(HPGW)was illustrated in the grinding process and an annular HPGW was designed and developed for high efficiency grinding of titanium alloy TC4.The manufacture was performed of annular heat pipe in the wheel consisting of three processes of vacuum pumping,working fluid filling and mechanical sealing.Finally,grinding experiments with different wheels(HPGW and non-HPGW) were carried out to verify the effect of enhancing heat transfer in the grinding zone under the same grinding condition for titanium alloy TC4.The results show that using the HPGW can effectively reduce the grinding temperature and prevent burnout in the grinding process.