3D multiphysics model for the simulation of electrochemical machining of stainless steel (SS316)

In electrochemical machining (ECM)—a method that uses anodic dissolution to remove metal—it is extremely difficult to predict material removal and resulting surface finish due to the complex interaction between the numerous parameters available in the machining conditions. In this paper, it is argued that a 3D coupled multiphysics finite element model is a suitable way to further develop the ability to model the ECM process. This builds on the work of previous researchers and further claims that the overpotential available at the surface of the workpiece is a crucial factor in ensuring satisfactory results. As a validation example, a real-world problem for polishing via ECM of SS316 pipes is modelled and compared to empirical tests. Various physical and chemical effects, including those due to electrodynamics, fluid dynamic, and thermal and electrochemical phenomena, were incorporated in the 3D geometric model of the proposed tool, workpiece, and electrolyte. Predictions were made for current density, conductivity, fluid velocity, temperature, and crucially, with estimates of the deviations in overpotential. Results revealed a good agreement between simulation and experiment and these were sufficient not only to solve the immediate real problem presented but also to ensure that future additions to the technique could in the longer term lead to a better means of understanding a most useful manufacturing process.