放电通道振荡特性分析及其蚀除机理的研究  

Analysis of the Plasma Oscillation and Erosion Mechanish in Electrical Discharge Channel

作　　者：倪杨[1] 郭常宁[1] 薛锐[1] 

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《电加工与模具》2009年第1期9-12,共4页Electromachining & Mould

摘　　要：从理论上对单脉冲放电通道的等离子体振荡特性进行了分析,发现其振荡频谱包含了金属晶格振动的本征频率。由此提出了受激原子共振的观点:在放电电流上升阶段,因放电通道中等离子体振荡频率可覆盖金属晶格振动频率,会使电极材料表面晶格原子产生共振或接近共振,加剧放电的热作用,使电极表面材料以"共振"形式去除;而在放电电流趋于平稳后,等离子体振荡频率则远远小于晶格振动频率,电极材料表面晶格原子不具备共振的必要条件,此时材料主要是以"碰撞"形式去除。从这个观点出发,说明了放电电流初始阶段和短脉冲加工是对电极消耗影响较大的原因。The plasma oscillation spectrum of electrical discharge channel is analyzed, and the eigenfrequency of metal crystal lattice vibration is discovered in the spectrum. The conception of atom resonance is put forward. At the preliminary stage （the rising current stage）, because the plasma oscillation spectrum includes the frequency of metal crystal lattice vibration, the plasma resonates, or nearly resonates in the atoms on electrode surface and intensifies the heat action generated by electrical discharge, which means the atoms on electrode surface could be emitted easily, and this model of material remove is defined as ＂resonance remove＂. At the stable stage, the plasma frequency is far below the frequency of metal crystal lattice vibration. Prerequisite for the atom resonance on electrode surface doesn＇t exist, so the material is mainly removed by collision. From this point of view, the discovery explains the early stage and a short pulse has a strong influence on electrode wear.

关 键 词：电火花加工 放电通道 等离子体振荡 原子共振 

分 类 号：TG661[金属学及工艺—金属切削加工及机床]