Abstract
Electrochemical machining (ECM) is characterized amongst other things, by extremely high current densities and a high dissolution rate of material. Due to the extreme current densities under ECM conditions, tungsten carbide forms adherent, supersaturated, viscous films of polytungstates close to the interface. This film is permanently dissolved by electrolyte flow and is reproduced at the electrode surface. The dissolution proceeds in an active state up to 30 A cm−2. An additional layer is formed at higher current densities which means that there is a passive state and the presence of high-field oxide films with thicknesses around 10 nm. The complex interaction between current, field strength, and oxide thickness yields a constant resistance to the oxide film. The formation of an oxide film is also indicated by the onset of oxygen evolution which consumes about 20% of anodic charge. The interaction of ionic currents (oxide formation and dissolution) and electronic currents (oxygen evolution) is small due to completely different conduction mechanisms.
Similar content being viewed by others
References
Bannard J (1977) Electrochemical machining. J Appl Electrochem 7(1):1–29. https://doi.org/10.1007/BF00615526
Datta M (1993) Anodic dissolution of metals at high rates. IBM J Res Dev 37(2):207–226. https://doi.org/10.1147/rd.372.0207
McGeough J (1974) Priciples of electrochemical machining. Chapman and Hall, London
Schneider M, Lohrengel MM (2017) Electrochemical machining. In: Breitkopf C, Swider-Lyons K (eds) Springer-Handbook of Electrochemical Energy. Springer, Dordrecht, pp 941–971
Landolt D (1972) Flow channel cell apparatus for high rate electrolysis studies. Rev Sci Instrum 43(4):592–595. https://doi.org/10.1063/1.1685699
Lohrengel MM, Rosenkranz C, Klüppel I, Moehring A, Bettermann H, van Bossche BD, Deconinck J (2004) Electrochim Acta 49(17-18):2863–2870. https://doi.org/10.1016/j.electacta.2004.01.068
Schneider M, Schroth S, Schubert N, Michaelis A (2012) In-situ investigation of the surface-topography during anodic dissolution of copper under near-ECM conditions. Mater Corros 63(2):96–104. https://doi.org/10.1002/maco.201005716
Bockris JOM, Khan SUM (1993) Surface electrochemistry—a molecular level approach. Plenum Press, New York. https://doi.org/10.1007/978-1-4615-3040-4
Rosenkranz C, Lohrengel MM, Schultze JW (2005) The surface structure during pulsed ECM of iron in NaNO3. Electrochim Acta 50(10):2009–2016. https://doi.org/10.1016/j.electacta.2004.09.010
Glarum SH, Marshall JH (1985) J Electrochem Soc 132:2872–2885
Matlosz M, Magaino S, Landolt D (1994) J Electrochem Soc 141:410–418
Datta M, Mathieu HJ, Landolt D (1979) Anodic film studies on nickel under high rate transpassive dissolution conditions. Electrochim Acta 24(8):843–850. https://doi.org/10.1016/0013-4686(79)87007-3
Datta M, Landolt D (1975) J Electrochem Soc 122:1466–1472
Datta M, Mathieu HJ, Landolt D (1984) J Electrochem Soc 131:2484–2489
Datta M, Landolt D (1980) On the role of mass transport in high rate dissolution of iron and nickel in ECM electrolytes—I. Chloride solutions. Electrochim Acta 25(10):1255–1262. https://doi.org/10.1016/0013-4686(80)87130-1
Datta M, Landolt D (1980) On the role of mass transport in high rate dissolution of iron and nickel in ECM electrolytes—II. Chlorate and nitrate solutions. Electrochim Acta 25(10):1263–1271. https://doi.org/10.1016/0013-4686(80)87131-3
Datta M, Landolt D (1981) Electrochemical machining under pulsed current conditions. Electrochim Acta 26(7):899–907. https://doi.org/10.1016/0013-4686(81)85053-0
Lohrengel MM (2005) Pulsed electrochemical machining of iron in nano3: fundamentals and new aspects. Mater Manuf Process 20(1):1–9. https://doi.org/10.1081/AMP-200041591
Moehring A (2004) Entwicklung einer elektrochemischen Durchflusszelle zur Untersuchung des Elektrochemischen Senkens (ECM, Electrochemical Machining). Dissertaion thesis, Heinrich-Heine-Universität, Düsseldorf
Rataj K, Hammer C, Walther B, Lohrengel MM (2013) Quantified oxygen evolution at microelectrodes. Electrochim Acta 90:12–16. https://doi.org/10.1016/j.electacta.2012.12.009
Aladjem A, Brandon DG, Yahalom J (1970) Electron-beam crystallization of anodic oxide films. Electrochim Acta 15(5):663–671. https://doi.org/10.1016/0013-4686(70)90029-0
Ammar IA, Salim R (1971) Anodic behaviour of tungsten—I. Oxidation kinetics in acid media. Corros Sci 11(8):591–609. https://doi.org/10.1016/S0010-938X(71)80056-2
Ammar IA, Salim R (1972) Anodic polarization of tungsten in neutral and alkaline solutions under conditions of anode film growth. Werkst Korros 23(3):161–167. https://doi.org/10.1002/maco.19720230302
Di Quarto F, Di Paola A, Sunseri C (1980) J Electrochem Soc 127:1016–1021
Vermilyea DA (1963) Journal of The Electrochem Society 110:345
Arora MR, Kelly R (1977) J Electrochem Soc 124:1493–1499
Khalil N, Leach JS (1986) The anodic oxidation of valve metals—I. Determination of ionic transport numbers by α-spectrometry. Electrochim Acta 31(10):1279–1285. https://doi.org/10.1016/0013-4686(86)80148-7
Rataj KP (2013) Elektrochemische Charakterisierung technisch relevanter anodischer Oxidschichten bei niedrigen und höchsten Stromdichten. dissertation thesis, Heinrich-Heine-Universität Düsseldorf
Walther B, Schilm J, Michaelis A, Lohrengel MM (2007) Electrochemical dissolution of hard metal alloys. Electrochim Acta 52(27):7732–7737. https://doi.org/10.1016/j.electacta.2006.12.038
Lohrengel MM (1993) Mat Sci Eng R11:243–294
Schultze JW, Vetter KJ (1973) The influence of the tunnel probability on the anodic oxygen evolution and other redox reactions at oxide covered platinum electrodes. Electrochim Acta 18(11):889–896. https://doi.org/10.1016/0013-4686(73)85043-1
Schultze JW (1970) Potentiostatische Messungen zur Sauerstoffentwicklung und Oxidschichtbildung an Platinelektroden. Z Phys Chem 73(1_3):29–47. https://doi.org/10.1524/zpch.1970.73.1_3.029
Schneider M, Schroth S, Richter S, Hohn S, Schubert N, Michaelis A (2011) In-situ investigation of the interplay between microstructure and anodic copper dissolution under near-ECM conditions—Part 1: the active state. Electrochim Acta 56(22):7628–7636. https://doi.org/10.1016/j.electacta.2011.06.075
Landolt D (2007) Corrosion and surface chemistry of metals. EPFL Press Lausanne: 59–61 and 89–91
Chung-Cherng L, Pouyan S (1993) Role of screw axes in dissolution of willemite. Geochim Cosmochim Acta 57(8):1649–1655. https://doi.org/10.1016/0016-7037(93)90104-5
Acknowledgements
The authors gratefully thank the German Research Foundation (DFG) for their financial support (LO 319/16-2, MI 509/16-2, and SCHN 745/11-2).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Schubert, N., Schneider, M., Michaelis, A. et al. Electrochemical machining of tungsten carbide. J Solid State Electrochem 22, 859–868 (2018). https://doi.org/10.1007/s10008-017-3823-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10008-017-3823-9