Method for controlling the area of the electrolyte outlets in the flow field simulation and experimental verification of electrochemical machining

Abstract

Electrochemical machining (ECM) is regarded as a promising and cost-effective manufacturing method for difficult-to-cut materials with complex shapes and structures. Many methods have been successfully developed for the flow field state of machining gaps, which is a key factor affecting machining performance in ECM engineering practice. However, little attention has been given to the area of the electrolyte outlets. This study attempts to present a method for controlling the area of the electrolyte outlets in the flow field simulation and experimental verification of electrochemical machining. The simulation results indicate that the convergent outlet mode can effectively enhance the turbulent effect of the fluid in the inter-electrode gap, especially in the near-wall region, and improve the mass transfer effect of electrolyte. Meanwhile, the simulation results also showed that better material removal rate (MRR) and surface roughness can be obtained when the convergent degree is about 50–70% combined with the effects of bubble volume compression and flow velocity reduction. The experimental results confirmed that the convergent outlet mode can obtain better MRR and surface roughness. Energy-dispersive X-ray spectroscopy results of machined specimens showed that oxides with strong adhesion on the specimen’s surface were effectively eliminated due to stronger turbulence effect under convergent outlet conditions. This should be considered as the main reason for improving machining performance by changing the electrolyte outlet area. These conclusions can provide some useful assistance for ECM engineering practice.