Influence of grain size and cobalt content on machinability of tungsten carbide with diamond-coated tools
Markus DIEGEL, Markus MEURER, Thomas BERGS
Abstract. Tungsten carbide is an important material for manufacturing cutting tools, molds and dies due to its combination of high hardness and high resistance to mechanical loads and wear. The primary restriction associated with utilizing this material pertains to the time-consuming and costly machining process, which is attributed to its low machinability. As an alternative to conventional electro discharge machining, milling with diamond-coated carbide tools has shown promising results. Due to a lack of knowledge about the interactions between the tungsten carbide to be machined, the tool and the process parameters, the economic advantages of the milling process are currently not fully utilized. In application of the cutting tools, a self-sharpening effect due to flaking of the coating on the rake face occurs, which results in improved cutting conditions. The present study addressed the prevailing knowledge cap regarding the interaction between material composition, parameter selection and tool design. Tungsten carbides with different compositions were machined in orthogonal cutting tests. In the investigations, increasing grain size and cobalt content caused a reduced thermomechanical process load and therefore delayed a favorable self-sharpening effect.
Keywords
Orthogonal Cutting, Tungsten Carbide, Diamond Coating, Coating Flaking
Published online 5/7/2025, 10 pages
Copyright © 2025 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA
Citation: Markus DIEGEL, Markus MEURER, Thomas BERGS, Influence of grain size and cobalt content on machinability of tungsten carbide with diamond-coated tools, Materials Research Proceedings, Vol. 54, pp 1826-1835, 2025
DOI: https://doi.org/10.21741/9781644903599-196
The article was published as article 196 of the book Material Forming
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
References
[1] W. Böhlke, Hartmetall – ein moderner Hochleistungswerkstoff, in: Materialwissenschaften und Werkstofftechnik, no. 33, 2002, pp. 575–580. https://doi.org/10.1002/1521-4052(200210)3 3:103.0.CO;2-1
[2] F. Klocke, Fertigungsverfahren 1, Berlin, Heidelberg: Springer, 2018. https://doi.org/10.1007/978-3-662-54207-1
[3] A. S. Pshenishnyuk and J. B. Hawkyard, Critical forming force in rotary forging and the application of tungsten carbide dies, In: International Journal of Mechanical Sciences, vol. 31, no. 6, 1989, pp. 471–476. https://doi.org/10.1016/0020-7403(89)90081-7
[4] M. P. Jahan, M. Rahman, and Y. S. Wong, A review on the conventional and micro-electrodischarge machining of tungsten carbide, In: International Journal of Machine Tools and Manufacture, vol. 51, no. 12, 2011, pp. 837–858. https://doi.org/10.1016/j.ijmachtools.2011.08.016
[5] K. Liu, X. P. Li, M. Rahman, and X. D. Liu, CBN tool wear in ductile cutting of tungsten carbide, In: Wear, vol. 255, 7-12, 2003, pp. 1344–1351. https://doi.org/10.1016/S0043-1648(03)00061-9
[6] R. Kuppuswamy and N. Mkhize, Near Ductile Regime Machining of Tungsten Carbide insert through Control of Cutting Speed Parameter While Using a Poly-Crystalline Diamond Tool, In: Procedia Manufacturing, vol. 8, 2017, pp. 549–556. https://doi.org/10.1016/j.promfg.2017.02.070
[7] W. Hintze, S. Steinbach, C. Susemihl, and F. Kähler, HPC-milling of WC-Co cemented carbides with PCD, In: International Journal of Refractory Metals and Hard Materials, vol. 72, 2018, pp. 126–134. https://doi.org/10.1016/j.ijrmhm.2017.12.019
[8] M. Ottersbach, Belastungsspezifische Werkzeug- und Prozessauslegung für die Schlichtfräsbearbeitung von Hartmetall, Aachen: Apprimus Verlag, 2018.
[9] M. Okada, R. Suzuki, A. Kondo, H. Watanabe, T. Miura, and M. Otsu, Evaluation of finished surface of cemented carbide by direct cutting using diamond-coated carbide end mill, In: Procedia CIRP, vol. 77, 2018, pp. 114–117. https://doi.org/10.1016/j.procir.2018.08.234
[10] M. Okada, R. Suzuki, H. Watanabe, M. Otsu, and T. Miura, Cutting Characteristics of Direct Milling of Cemented Tungsten Carbides Using Diamond-Coated Carbide End Mills with Untreated and Treated Cutting Edge, In: IJAT, vol. 13, no. 1, 2019, pp. 58–66. https://doi.org/10.20965/ijat.2019.p0058
[11] M. Okada et al., Surface quality of cemented tungsten carbide finished by direct cutting using diamond-coated carbide end mill, In: Journal of Manufacturing Processes, vol. 61, 2021, pp. 83–99. https://doi.org/10.1016/j.jmapro.2020.11.004
[12] L. Yin, A. C. Spowage, K. Ramesh, H. Huang, J. P. Pickering, and E. Vancoille, Influence of microstructure on ultraprecision grinding of cemented carbides, In: International Journal of Machine Tools and Manufacture, vol. 44, no. 5, 2004, pp. 533–543. https://doi.org/10.1016/j.ijmachtools.2003.10.022
[13] M. Diegel, M. Meurer, and T. Bergs, Improved cutting of tungsten carbide after flaking of diamond coating, In: Procedia CIRP, 2024 (published soon).
[14] T. G. Bifano, T. A. Dow, and R. O. Scattergood, Ductile-Regime Grinding: A New Technology for Machining Brittle Materials, In: Journal of Engineering for Industry, vol. 113, no. 2, 1991, pp. 184–189. https://doi.org/10.1115/1.2899676
