钛合金TC4不同介质放电加工蚀除机理研究  

Material Removal Mechanism of the Ti-6Al-4V EDM with Different Dielectrics

作　　者：王怀志[1] 刘志东[1] 田宗军[1] 王祥志[1] 陈文安[1] 

机构地区：[1]南京航空航天大学机电学院,江苏南京210016

出　　处：《电加工与模具》2012年第1期24-28,共5页Electromachining & Mould

基　　金：航空科学基金资助项目(20100343004)

摘　　要：为研究钛合金TC4在蒸馏水和火花油中放电加工时材料蚀除机理的差异,在相同条件下进行钛合金TC4放电加工试验,分别对放电波形、极性效应、表面微观形貌及加工表面主要成分等进行了对比分析。结果表明:蒸馏水的冷却性和流动性较好,可很好地进行极间冷却并进行消电离,放电能量较大时加工依然很稳定,大大提高了加工效率;相对而言,火花油的冷却性和流动性较差,且易析碳,频繁发生拉弧、二次放电和短路等现象,脉冲利用率低,加工效率较低。蒸馏水中工件表面产生的氧化钛熔点较火花油中形成的碳化钛低,更易于蚀除,因此蒸馏水中可获得更高的材料去除率。In this paper, the discharge waveform, surface topography, surface element composi- tion and the polarity effect, using distilled water and kerosene as dielectrics respectively, are studied to discover difference of material removal mechanism of TC4 EDM. The results show that the distilled water has outstanding fluidity and cooling performance which can promptly cool the discharge channel and deionize. When the discharge energy is large, the EDM status in distilled water can be stable as well, so the material removal rate can be improved greatly. The fluidity and cooling performance of kerosene is bad and the EDM in kerosene exists carbon deposition, which can lead to frequent arc discharge, secondary discharge and short circuit in the TCA EDM, reducing the pulse utilization rate, so the material removal rate is low. The TiO formed in distilled water on the TC4 workpiece surface has lower melting temperature than TiC formed in the kerosene, needing less energy to remove, so the TCA EDM in distilled has higher material removal rate.

关 键 词：TC4 电火花加工 材料蚀除 

分 类 号：TG661[金属学及工艺—金属切削加工及机床]