Abstract:

A new method called forming by spark-induced controllable combustion and EDM finishing was proposed. It could gain the purpose of efficient removal rate and lower relative electrode wear rate, where the high-pressure oxygen was reacted with the melting metal, and pushed the products out from working region. In addition, the normal EDM which was carried out in oxygen off stage was finishing the surface to insure the accuracy and surface quality. The experiments were carried out by four methods: EDM in kerosene, EDM in water, continuous combustion and intermittent combustion. The results show that the material removal rate of intermittent combustion is increased 4.28 times than that of EDM in kerosene, and relative electrode wear rate is reduced 72%. This paper analyzed the machining mechanism of intermittent combustion by machining wave form, and also analyzed the processing characteristics of intermittent combustion by electrode couple surface micro-morphology and composition.

Key words: electrical discharge machining(EDM), controllable combustion, intermittent oxygen, finishing

摘要：

提出一种新加工方法——放电诱导可控烧蚀及电火花修整成形加工（简称间歇烧蚀加工）。利用极间金属材料在高压氧气间歇通入阶段产生剧烈烧蚀并将蚀除产物吹离加工区域这一特性来实现材料的高效蚀除及较低电极相对损耗率的目的，且在氧气关闭阶段进行常规电火花加工以对表面进行修整，保证了加工表面精度及质量。与火花油、水中传统加工和持续烧蚀加工的试验对比表明：在相同电参数下，间歇烧蚀加工的材料去除率较传统火花油中的电火花加工提高了4.28倍，相对电极损耗率降低了72%。通过放电波形分析了间歇烧蚀的加工机理，并基于电极对的表面微观形貌和成分分析对其加工特点进行了研究。

关键词: 电火花加工, 可控烧蚀, 间歇氧气, 修整