深小孔电解加工中工具电极端面氧化行为研究

管状电极深小孔电解加工中电极端面的氧化膜层是引起电极短路的主要原因。采用扫描电镜(SEM)分析了工具电极端面在单向正脉冲和正负脉冲加工后的形貌和成分,在此基础上对氧化膜层的形成机制进行了分析。研究表明:采用单向正脉冲加工时管状电极端面形成连续疏松的氧化膜层,其成分主要是C 和Si 的氧化物;工具电极的吸附作用是形成氧化膜层的主要原因;采用适当比例的正负脉冲加工可有效抑制氧化膜层的形成,对已形成氧化膜层具有去除作用,显著提高深小孔电解加工的稳定性。

Research on Oxidation Behavior of End Face of Tool Electrode in Electrochemical Machining of Small Deep Hole

In the deep hole electrochemical machining of tubular electrode, the main reason of short circuit is oxidation film layer on the end face of electrode. The morphology and composition of the tool electrode end face processed by unidirectional pulse and bidirectional pulse are analyzed using scanning electron microscopy (SEM),and the formation mechanism of oxide film layer is also analyzed. The results show that the continuous loose oxidation film layer is formed on the end face of tubular electrode by using unidirectional pulse, its compositions are mainly the oxides of C and Si,the main reason of forming oxide film layer is the adsorption effect of tool electrode,using the right proportion of positive and negative pulse can inhibit the forming of oxidation film and the formed oxidation film layer could be removed efficiently, and the stability of electrochemical machining deep holes can be improved apparently.