Prevention of Material Deterioration in ECM of Sintered Carbide with Iron Ions
Akihiro Goto*,†, Atsushi Nakata*, Sicong Wang*, and Nagao Saito**
*Department of Mechanical Engineering, Shizuoka Institute of Science and Technology
2200-2 Toyosawa, Fukuroi, Shizuoka 437-8555, Japan
**S.N. Engineering Laboratory, Aichi, Japan
This study focuses on electrochemical machining as a method of processing sintered carbide at high speeds. Previous studies have suggested the possibility of using electrochemical machining to achieve high-speed machining of sintered carbide. However, there has been strong resistance in industry against bringing sintered carbide into contact with a conductive liquid. This is because the material quality of sintered carbide is degraded by the elution of Co when it is brought into contact with a conductive liquid.
In previous reports, the authors have shown that it is possible to control two modes of Co elution occurring during electrochemical machining: the elution from sintered carbide when it comes into contact with an electrolyte, and the selective elution of Co due to difference in the speeds of WC dissolution and elution of Co when sintered carbide is connected to an electrical source for processing. It was shown that it is possible to control the elution Co in sintered carbide when it comes into contact with an electrolyte by adding Co ions to the electrolyte to increase the concentration of Co ion, and that it is possible to prevent the excessive elution of Co by using a bipolar electrical source for machining. Although we showed that it is possible to carry out electrochemical machining of sintered carbide without degrading its quality, adding of large amounts of Co ions to the electrolyte entails a high cost. In this report, therefore, we describe the addition of Fe ions instead of Co ions to perform electrochemical machining of sintered carbide without quality degradation.
-  S. Maeda, N. Saito, and Y. Haishi, “Principle and Characteristics of Electro-Chemical Machining, Mitsubishi Electric Techinical Repot (Mitsubishi Denki Giho),” Vol.41, No.10, pp. 1267-1279, 1967 (in Japanese).
-  H. Kurafuji, “Electrochemical machining,” The J. of the Institute of Electrical Engineers of Japan, Vol.85-5, No.920, pp. 743-747, 1965 (in Japanese).
-  T. Masuzawa and M. Kimura, “Electrochemical surface finishing of tungsten carbide alloy,” Annals of the CIRP, Vol.40, No.1, pp. 199-202, 1991.
-  B. Walther, J. Schilm, A. Michaelis, and M. M. Lohrengel, “Electrochemical dissolution of hard metal alloys,” Electrochimica Acta, Vol.52, pp. 7732-7737, 2007.
-  N. Shibuya, Y. Ito, and W. Natsu, “Electrochemical machining of tungsten carbide alloy micro-pin with NaNO3 solution,” Int. J. of Precision Engineering and Manufacturing, Vol.13, Issue 11, pp. 2075-2078, 2012.
-  S .H. Choi, B. H. Kim, H. S. Shin, and C. N. Chu, “Analysis of the electrochemical behaviors of WC-Co alloy for micro ECM,” J. of Materials Proc. Technology, Vol.213, pp. 621-630, 2013.
-  K. Mizugai, N. Shibuya, and M. Kunieda, “Study on Electrolyte Jet Machining of Cemented Carbide,” Int. J. of Electrical Machining (IJEM), No.18, pp. 23-28, 2013.
-  T. Koyanoa and M. Kunieda, “Ultra-short pulse ECM using electrostatic induction feeding method,” Procedia CIRP, Vol.6, pp. 390-394, 2013.
-  W. Natsu and D. Kurahata, “Influence of ECM pulse conditions on WC alloy micro-pin fabrication,” Procedia CIRP, Vol.6, pp. 401-406, 2013.
-  N. Schubert, M. Schneider, and A. Michaelis, “Electrochemical Machining of cemented carbides,” Int. J. of Refractory Metals and Hard Materials, Vol.47, pp. 54-60, 2014.
-  V. A. Mogilnikov, M. Ya. Chmir, Y. S. Timofeev, and V. S. Poluyanov, “Diamond-ECM grinding of sintered hard alloys of WC-Ni,” Procedia CIRP, Vol.42, pp. 143-148.
-  K. Miyoshi and M. Kunieda, “Fabrication of micro rods of cemented carbide by electrolyte jet turning,” Procedia CIRP, Vol.42, pp. 373-378, 2016.
-  A. N. Zaitsev, A. L. Belogarsky, I. L. Agafonov, N. Z. Gimaev, R. R. Unchutdinov, V. N. Kusenko, and R. A. Alimbekov, “Performing Holes of Small Diameter in Steel Foil Using Method of Multi-Electrode Precise Electrochemical Machining,” Proc. of ISEM, Vol.12, pp. 555-564, 1998.
-  R. Schuster, V. Kirchner, P. Allongue, and G. Ertl, “Electrochemical Micromachining, Science,” Vol.289, No.5476, pp. 98-101, 2000.
-  A. D. Silva and H. Altena, “Accuracy Improvements in ECM by Prediction and Control of the Localisation Effects,” Int. J. of Electrical Machining (IJEM), Vol.7, pp. 25-30, 2002.
-  E. Uhlmann, U. Doll, R. Foerster, R. Nase, and R. Schikofsky, “High Precision Manufacturing Using PEM,” Proc. of ISEM, Vol.13, pp. 261-268, 2001.
-  K. P. Rajurkar, D. Zhu, J. A. McGeough, J. Kozak, and A. D. Silva, “New Developments in Eletro-Chemical machining,” Annals of the CIRP, Vol.48, No.2, pp. 567-579, 1999.
-  Y. Sakai, A. Goto, K. Nakamura, and S. Sato, “Corrosion Problem and Prevention Technology in Wire Electrical Discharge Machining,” Int. J.of Electrical Machining (IJEM), No.11, pp. 35-38, 2006.
-  A. M. Humani and H. E. Exner, “Electrochemical behaviour of tungsten-carbide hardmetals,” Materials Science and Engineering, Vol.A209, pp. 180-191, 1996.
-  B. Schnydera, C. S. Sittiga, and R. Kötz, “Investigation of the electrochemical behaviour of WC–Co hardmetal with electrochemical and surface analytical methods,” Proc. of the 22nd European Conf. on Surface Science, pp. 1240-1245, 2004.
-  A. Goto, T. Moroi, . Uematsu, N. Saito, N. Mohri, and T. Yuzawa, “Electrochemical Machining of Sintered Carbide (1st Report) – Prevention of Excessive Co Elution –,” J. of the Japan Society of Electrical Machining Engineers, Vol.46, No.113, pp. 117-124, 2015 (in Japanese).
-  A. Goto, A. Nakata, and N. Saito, “Study on Electrochemical Machining of Sintered Carbide,” Procedia CIRP, Vol.42, pp. 402-406, 2016.
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