An Experimental Research on Surface Roughness of Fine-Grained Graphite Machined by Micro End Mills

  • Hua Qiu Kyushu Sangyo University
  • Akio Kubo Kyushu Sangyo University


This paper presents an experimental research on surface roughness of fine-grained graphite machined by micro milling. POCO EDM-3 and POCO EDM-AF5 fine-grained graphite were adopted as workpiece material. A full groove milling was performed respectively using a tungsten carbide end mill with or without diamond-coating dedicated to graphite cutting. EDM-AF5, which has a smaller grain size than EDM-3, showed better property for surface roughness. The diamond-coated tool demonstrated more excellent abilities for micro milling than the uncoated tool, achieving more beautiful machining surface under higher cutting speed and feed rate condition. The influence degree of the grain size and the cutting parameters including cutting speed, feed rate and cutting depth on surface roughness was analyzed by using ANOVA method. The analysis results proved that the feed rate and the grain size have the most significant influence and the cutting depth only has a minor effect on the surface roughness, while the cutting speed is not an influence factor. Regression equations to predict the surface roughness value from related factors were derived with the regression analysis. Through additional verification experiments, the effectiveness of these equations was also confirmed.


Y. Takeuchi, “Micromilling”, Journal of the Japan Society for Precision Engineering, Vol.68, No.2, pp.167-170, 2002(In Japanese).

T. Masuzawa, “Micro-EDM”, Journal of the Japan Society for Precision Engineering, Vol.68, No.2, pp.180-184, 2002(In Japanese).

K. H. Ho and S.T. Newman, "State of the art electrical discharge machining (EDM)”, International Journal of Machine Tools and Manufacture, Vol.43, No.13, pp.1287-1300, 2003. DOI: 10.1016/S0890-6955(03)00162-7

N. M. Abbas, D. G. Solomon and M. F. Bahari, “A review on current research trends in electrical discharge machining (EDM)”, International Journal of Machine Tools and Manufacture, Vol.47, No.7-8, pp.1214-1228, 2007. DOI: 10.1016/j.ijmachtools.2006.08.026

S. Saito and H. Itami, “Advanced die and mold manufacturing technology by utilizations of new types of graphite materials”, Machines and Tools, Separate volume of May 2009 issue, pp.8-15, 2009(In Japanese).

F. Klocke, A. Klink, D. Veselovac, D. K. Aspinwall, A. L. Soo, M. Schmidt, J. Schilp, G. Levy and J.-P. Kruth, “Turbomachinery component manufacture by application of electrochemical, electro-physical and photonic processes”, CIRP Annals-Manufacturing Technology, Vol.63, No.2, pp.703- 726, 2014. DOI: 10.1016/j.cirp.2014.05.004

J. Mercer, “Graphite vs. copper”, EDM Technical Manual, Poco Graphite, Inc. 2014.

I. Ayesta, B. lzquierdo, J. A. Sa ́nchez, J. M. Ramos, S. Plaza, I. Pombo, N. Ortega, H. Bravo, R. Fradejas and I. Za- makona, “Influence of EDM parameters on slot machining in C1023 aeronautical Alloy”, Procedia CIRP, Vol.6, pp.129- 134, 2013. DOI: 10.1016/j.procir.2013.03.059

E. Uhlmann and D. C. Domingos, “Development and optimization of the die-sinking EDM-technology for machining the nickel-based alloy MAR-M247 for turbine components”, Procedia CIRP, Vol.6, pp.180-185, 2013. DOI: 10.1016/j.procir.2013.03.102

F. Klocke, M. Holsten, D. Welling, A. Klink and R. Perez, “Influence of Threshold Based Process Control on Sinking EDM of a High Aspect Ratio Geometry in a Gamma Titanium Aluminide”, Procedia CIRP, Vol.35, pp.73-78, 2015. DOI: 10.1016/j.procir.2015.08.083

A. Torres, I. Puertas and C. J. Luis, “EDM machinability and surface roughness analysis of INCONEL 600 using graphite electrodes”, The International Journal of Advanced Manufacturing Technology, Vol.84, pp.2671-2688, 2016. DOI: 10.1007/s00170-015-7880-x

M. Zeis, “Deformation of thin graphite electrodes with high aspect radio during sinking electrical discharge machining”, CIRP Annals-Manufacturing Technology, Vol.66, No.1, pp.185-188, 2017. DOI: 10.1016/j.cirp.2017.04.139

O. Flano, I. Ayesta, B. Izquierdo, J. A. Sanchea, Y. Zhao and M. Kunieda, “Improvement of EDM performance in high-aspect radio slot machining using multi-holed electrodes”, Precision Engineering, Vol.51, pp.223-231, 2018.DOI: 10.1016/j.precisioneng.2017.08.014

R.B.Schroeter,R.KratochvilandJ.O.Gomes, “High-speed finishing milling of industrial graphite electrodes”, Journal of Materials Processing Technology, Vol.179, No.1-3, pp.128-132, 2006. DOI:10.1016/j.jmatprotec.2006.03.076

L. Zhou, C. Y. Wang and Z. Qin, “Tool wear characteristics in high-speed milling of graphite using a coated carbide micro endmill”, Proceedings of the Institution of Mechanical Engineers Part B: Journal of Engineering Manufacture, Vol.223, No.3, pp.267-277, 2009. DOI: 10.1243/09544054JEM1326

M. Hashimoto, K. Kanda and T. Tsubokawa, “Reduction of diamond-coated cutting tool wear during graphite cutting”, Precision Engineering, Vol.51, pp.186-189, 2018. DOI: 10.1016/j.precisioneng.2017.08.009

C. Wang, “High-speed milling of graphite electrode with endmill of small diameter”, Chinese Journal of Mechanical Engineering, Vol.20, No.4, pp.27-31, 2007. DOI: 10.3901/CJME.2007.04.027

G. Mijusˇkovic ́, P. Krajnik and J. Kopacˇ, “Analysis of tool deflection in micro milling of graphite electrodes”, The International Journal of Advanced Manufacturing Technology, Vol.76, pp.209-217, 2015. DOI: 10.1007/s00170-013-5536- 2

Z. Wan, D. Yang, L. Lu, J. Wu and Y.Tang, “Mechanism of material removal during orthogonal cutting of graphite/polymer composites”, The International Journal of Advanced Manufacturing Technology, Vol.82, pp.1815- 1821, 2016. DOI: 10.1007/s00170-015-7458-7

Y.-K. Yang, M.-T. Chuang and S.-S. Lin, “Optimization of dry machining parameters for high-purity graphite in end milling process via design of experiments methods”, Journal of Materials Processing Technology, Vol.209, No.9, pp.4395-4400, 2009. DOI:10.1016/j.jmatprotec.2008.11.021

D. Huo, C. Lin and K. Dalgarno, “An experimental investigation on micro machining of fine-grained graphite”, The International Journal of Advanced Manufacturing Technology, Vol.72, pp.943-953, 2014. DOI: 10.1007/s00170-014-5730- x

O. S. Lo ́pez, A. R. Gonza ́lez and I. H. Castillo, “Statistical analysis of surface roughness of machined graphite by means of CNC milling”, Ingenieria e Investigacion, Vol.36, No.3, pp.89-94, 2016. DOI: 10.15446/ing.investig.v36n3.53603

Transforming the world through poco materials, Entegris,, access date: 2019.12.

JIS B4053:2013, “Classification and Application of Hard Cutting Materials for Metal Removal with Defined Cutting Edges-Designation of the Main Groups and Groups of Application”, Japanese Standards Association.

Y. Kita, “Data Analysis and SPSS 2: Development”, Hokuju Shuppan, Inc.p.175, 2006(In Japanese).

How to Cite
Qiu, H., & Kubo, A. (2020). An Experimental Research on Surface Roughness of Fine-Grained Graphite Machined by Micro End Mills. Journal of the Institute of Industrial Applications Engineers, 8(3), 95.