Design of Completely Inserted and Feeding Electrode for Female Screw in Electrochemical Finishing

Abstract

This study discusses electrochemical finishing of female screw using different types of completely inserted electrodes as well as feeding electrodes for die material. In the experiment, four types of design electrode are completely inserted and put through both continuous and pulse direct current and another four types of electrode are used with the application of continuous direct current and axial electrode feed. The controlled factors include the chemical composition and the concentration of the electrolyte, the electrolyte temperature, the flow rate of electrolyte, rotational speed of the electrode, current density, and current rating. The parameters are electrolytic time, die material, pulse period, feed rate of the electrode, and electrode geometry. For inserted electrodes, an electrode with thin plate provides more sufficient discharge space, which is advantageous for polishing. The electrode of single plate performs better than the double plate. Pulse direct current can promote the effect of electrochemical finishing, but the machining time is longer and the cost is raised. For feeding electrodes, an electrode of one side borer tip and thinner heavy section performs the best polishing effect in the current investigation. The electrochemical finishing after screw cutting just needs quite short time to make the surface of female screw smoothing and bright.