Experimental and Numerical Investigations of Reducing Stray Corrosion and Improving Surface Smooth in Macro Electrolyte Jet Machining Titanium Alloys

Abstract

Recently, macro electrolyte jet machining has attracted considerable research attention because it is flexible and suitable for processing aerospace parts with complex profiles. However, in this process stray corrosion occurs easily at the edges of the grooves, affecting the machining localization. In the machining of titanium alloys, serious stray corrosion on the surface outside of the machining area occurs because titanium alloys are particularly sensitive to changes in the flow field and the electric field. Here, a method is proposed to reduce stray corrosion on the workpiece surface outside of the machining area during machining of titanium alloy. This method is shown to reduce the negative influence of the reflected electrolyte on the non-machined area near the machined groove edge and to improve the machining localization by restricting the jet direction and flow range of the reflected electrolyte. Based on an investigation of the slope of the tool end face and the distribution of the electrolyte gas–liquid phase, the end face of the tool was designed to slope downward. This reduced the electrolyte flow resistance and improved the electric intensity, which helped produce a smoother surface. Experiments show that the macro sinking and milling method not only removed electrolyte from the lateral edge of the groove, reducing stray corrosion and improving machining localization, but also rapidly removed electrolytic products in the machining area, improving surface quality. Brilliant silvery grooves were obtained using a tool with an appropriate downward slope angle along with the sinking and milling method.