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.

• Periodical: Key Engineering Materials (Volume 329)
• Pages: 231-236
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.329.231
• Online since: January 2007
• Authors: Pai Shan Pa
• Keywords: Die Material, Electrochemical Finishing, Electrode Design, Feeding Electrode, Female Screw, Inserted Electrode

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3 workpiece electrolyte flow electrolyte flow electrode rotation s0. 03 0. 3 workpiece electrolyte flow electrolyte flow electrode rotation s0. 03 feeding direction (a) System Schematics (b) Configuration of Tool and Workpiece Fig. 1 Experimental Set-Up (� Requirement • Design Feature) Fig. 2 Development of Electrode Design (Wt %) Fe C Si Mn P S Cr Mo Al V Cu Ni AISI H13 (SKD61) 90. 70 0. 38 0. 96 0. 43 0. 29 0. 03 5. 31 1. 08 / 0. 82 / / AISI D2 (SKD11) 88. 65 1. 40 0. 40 0. 30 0. 02 0. 03 8. 20 0. 80 / 0. 20 / / AISI P21 (NAK80) 92. 06 0. 13 0. 60 1. 50 / / / 0. 25 1. 12 / 1. 24 3. 1 AISI 4340 (SNCM439) 96. 48 0. 39 0. 30 0. 90 0. 02 0. 03 0. 80 0. 25 / / 0. 03 2. 0 � Short-time Polishing • Completely Inserted Electrode • Feeding Electrode � Eliminating Secondary Overcut � Increasing Effective Current Density � Large Discharge Space • Plate Form Electrode • Borer Type Electrode � Increasing Discharging Mobility • Pulse Direct Current • Single-Plate • Single-Borer φ16 30 30 R8 30 4 φ16 30 R8 4 Type A Type B Type C Type D (a) Inserted Electrodes 16φ 8 16 4 φ 8 4 Type A Type B Type C Type D (b) Feeding Electrodes Fig. 3 Design of Electrode Fig. 4 Electrochemical finishing with different types of inserted electrode at 0. 02mm of radial depth (4l/min, continuous DC, 30A/cm 2 ) AISI 4340 AISI P21 AISI D2 AISI H13 0.

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DOI: 10.17816/kazmj70902-38627

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9 1 Ra (µm) type A type B type C type D Fig. 7 Electrochemical finishing with different types of feeding electrode (AISI H13, 4l/min, Continuous DC, 10A, 4mm/min).