Analysis of Mechanisms Affecting the Tool in Pulsed Electrochemical Machining

Abstract

Electrochemical machining (ECM) is an important technology in machining difficult-to-cut materials. The contactless nature of ECM and anodic dissolution of the workpiece propound no tool ablation. Nevertheless, in a few studies, tool damages, namely the formation of pits and geometrical changes, have been observed, which is the investigative goal of this work. This study considers three hypotheses to investigate tool changes during pulsed electrochemical machining (PECM) which are hydrogen embrittlement, cavitation erosion, and cathodic corrosion. A systematic study of monitoring possible tool (1.4112 martensitic stainless steel) changes during ECM and PECM in aqueous NaNO3 electrolyte is performed. Experimental results of this study show that hydrogen embrittlement and cavitation erosion are not the reason for causing changes in the tool. Cathodic corrosion might be the reason for the changes in the tool in this study; however, more investigation is needed. The approach in this study is investigating the microstructure of the tool regarding different aspects before and after ECM and PECM, as the microstructure stores information regarding phenomena occurring during any process.