基于实时监控的金属结合剂金刚石微粉砂轮电火花精密整形  

ELECTRO-DISCHARGE FINE TRUING OFMETAL-BONDED FINE GRAIN DIAMOND WHEEL BASED ON REAL-TIME MONITORING

作　　者：金卫东[1] 任成祖[1] 华瑾海 王太勇[1] 

机构地区：[1]天津大学先进陶瓷与加工技术教育部重点实验室

出　　处：《金刚石与磨料磨具工程》2004年第6期43-47,共5页Diamond & Abrasives Engineering

基　　金：天津市自然科学基金资助项目 (0 4 360 331 1 )

摘　　要：采用金属结合剂超微细粒度超硬磨料砂轮实现硬脆材料的ELID(ElectrolyticIn -processDressing在线电解修整 )精密与超精密磨削是一项加工新技术。金属结合剂砂轮具有很高的强度、硬度及良好的耐磨性 ,但修整困难。与普通磨削砂轮不同 ,金属结合剂金刚石微粉砂轮的修整分为整形和修锐两个阶段。本文开发了基于组态软件LabVIEW的数据采集系统 ,研究了基于实时监控的金属结合剂金刚石微粉砂轮电火花精密整形技术。结果表明砂轮旋转周期中的放电电流曲线是否呈现局部放电特征可以作为新设定电参数是否具有加工能力的判据。砂轮整形过程中的放电电流曲线是否达到平滑 ,即是否出现周圈放电现象可以作为其是否还具有整形能力的判据。对于圆跳小于 10 μm砂轮精密整形来说 ,仅靠观察火花状况实施进给难以避免空载、拉弧甚至短路现象。通过整形电流波形的实时监控不仅可以方便地获取有效加工电规准 ,而且很容易避免极间短路现象、鉴别非正常工作状态。金属结合剂微粉砂轮的整形精度和效率不仅与电规准有关 ,而且受到电极形状、工作液的绝缘性能及最小进给量值的影响。实验表明以电解液作为工作液、采用平面电极 ,选定合适的电规准 ,W 10微粉金刚石砂轮最终的整形精度可达到圆跳小于 2 μm、锥度误差在 1μm以内 ,ELID (Electrolytic In-process Dressing) precision grinding and super precision grinding of hard and brittle materials with metal-bonded fine grain superabrasive grinding wheels is a new machining technology. The metal-bonded grinding wheel has higher strength, hardness, and better wear-resisting property, but its truing is quite difficult. Different from general grinding wheels, dressing of metal-bonded diamond grinding wheel includes two steps:truing and sharpening. In this paper, a data acquisition system based on LabVIEW is designed and achieved,and electro-discharge (ED) fine truing of metal-bonded fine grain diamond wheel based on real-time monitoring is studied.The results show whether the character of partial electric-discharge occurs in the truing current curve can be a criterion for machining capability of the electro-discharge specification at its presetting. And during ED truing of the wheels, an electrical parameter will have no longer truing ability when the truing current curve becomes smoother, namely there is electro-discharge phenomena on the whole circumference of wheel at the time. For fine truing of metal-bonded fine grain super abrasive grinding wheels with final truing accuracy less than 10μm, it is quite difficult to avoid in good time no-load,arc discharge and short circuit phenomena only by observing discharge spark.But real-time monitoring of the ED truing current not only makes obtaining efficient impulse current specification to be easy,but also is good for avoiding short circuit and identifying incorrect machining state. The truing accuracy and truing efficiency of metal-bonded fine grain diamond wheels depend on not only the discharge specification but also the electrode shape, insulating performance of the working fluid and the minimal feed quantity value. The experimental results show that with electrolyte as working fluid, flat plate electrode and proper truing specification, the final run-out of W10 grinding wheel by ED fine truing is less than 2μm, and the taper error within 1

关 键 词：金属结合剂金刚石砂轮 电火花精密整形 实时监控 有效整形电流 

分 类 号：TQ164[化学工程—高温制品工业] TG74[金属学及工艺—刀具与模具]