钛合金TC4电火花诱导可控烧蚀高效磨削技术研究

 利用大部分金属尤其是难加工金属的可燃特性,开发一种针对难加工金属材料的新加工工艺——电火花(EDM)诱导可控烧蚀高效磨削技术。采用开槽导电砂轮进行磨削加工,首先利用导电区域与加工材料产生电火花诱导放电并通入助燃氧气,使材料表面产生电火花引燃烧蚀并软化,然后将已烧蚀和软化的材料磨除,对钛合金TC4进行烧蚀磨削试验,并与常规电火花磨削和机械磨削进行对比,分析了材料去除率(RMM)、表面质量和机床主轴电机功率变化等指标。结果表明,在试验条件下,烧蚀磨削在放电利用率提高的同时可获得表面粗糙度为0.59 μm的加工表面,与机械磨削的表面粗糙度值相近,而相同条件下电火花磨削的表面粗糙度为1.29 μm。由于烧蚀后产生了软化层,在切深小于软化层厚度的条件下,相对于电火花磨削和机械磨削状况,烧蚀磨削主轴电机功率相比空载时的增加值分别降低了95.2%和96.8%。此工艺方法可大大提高难加工材料的可磨削性能。

Study of TC4 Controllable Burned Efficient Grinding Induced by Electrical Discharge Machining

A new process of efficient grinding technology is proposed which is based on electrical discharge machining(EDM) induced controllable burning of the workpiece to be machined.This process utilizes the flammability of a metal,especially difficult-cutting metal,and uses a slotted conductive wheel to grind.First,an EDM induced discharge is generated between the wheel and the material.Then the gap is filled with combustion-supporting oxygen to induce the material to burn and soften,and the burned and soften layer is subsequently removed.Work on titanium alloy TC4 by burned grinding is compared with EDM grinding and mechanical grinding.The material removal rate(MRR),surface quality,spindle motor power change,etc.,are analyzed.The result shows that burned grinding can improve the discharge efficiency with an roughness of 0.59 μm,similar to that of mechanical grinding,while the roughness of EDM is 1.29 μm.Because there is a softened layer in burned grinding,when the cutting depth is less than the softened layer,the spindle motor power increase from the no-load condition of burned grinding is respectively 95.2% and 96.8% less as compared with EDM grinding and mechanical grinding.This technology may improve the grinding performance of difficult-cutting materials greatly.