The effect of different dielectrics on material removal rate, surface roughness and white layer thickness in EDM process


  • Shukry H. Aghdeab Production Engineering and Metallurgy Department, University of Technology, Baghdad
  • Haneen L. Aldulaimy
  • Haneen L. Aldulaimy





Electrical Discharge Machining, Material Removal Rate, Surface Roughness, White Layer Thickness, Pulse-On-Time.


The electrical discharge machining (EDM) is a highly non-traditional manufacture method in which material exclusion happens because of repeated electrical discharges at small periods in the presence of a dielectric medium. It is adopted in numerous processes involving the industry of dies and molds, surface alloying, surface texturing of steel rolls, manufacture of aero engine parts and manufacture of the metallic prosthesis. In EDM, the key output factors are the material removal rate (MRR), the surface roughness (SR) and white layer thickness (WLT). The operational fluid has an imperative function in machining and effecting the MRR, SR, WLT and the properties of the machined surface. This study aims to investigate the influence of using different dielectric such as vegetable oil, transformer oil and gas oil to obtain the maximum MRR with lower surface roughness and minimum whit layer thickness in EDM for stainless steel 316L specimens with a copper electrode. The result shows that the vegetable oil can be used as a dielectric in EDM, it gives extreme MRR while the relative SR is lower and higher WLT when compared to transformer oil and gas oil. Analysis of variance results indicated that the current and pulse-on-time are the most important factors that effect on MRR, SR and WLT. The MRR in vegetable oil and transformer oil produced 66% and 61% higher MRR, respectively, than gas oil. Additionally, vegetable oil and transformer oil resulted in 38% and 13% lower SR than gas oil, while vegetable oil and transformer oil resulted 28% and 14% higher in WLT than gas oil.






[1] Kunieda M, Lauwers B, Rajurkar KP, Schumacher BM (2005)Advancing EDM through fundamental insight into the process.CIRP Annals-Manufacturing Technology 54(2):64–87.

[2] K.H Ho and S.T. Newman, "State of the art electrical discharge machining (EDM)," Int. J. Machine Tools Manufac., vol. 43, pp. 1287-1300, 2003.

[3] Mahdavinejad, R.A., Mahdavinejad, A., 2005. ED Machining of WC-Co. Journal of Materials Processing Technology 162-163, pp.637-643.

[4] Krar SF, Check AF (1997) Electrical discharge machining, Technology of Machine Tools. Glencoe/McGraw-Hill, New York.

[5] Soo Hiong Lee, Xianoping Li. 2003. Study of the surface integrity of the machined workpiece in the EDM of Tungsten Carbide" Journal of Materials processing Technology 139, pp. 315-321

[6] Yonghong Liu, et al. "Investigation on the influence of the dielectrics on the material removal characteristics of EDM." Journal of Materials Processing Technology 214.5 (2014): 1052-1061.

[7] Wang, Xiangzhi, et al. "Research on the influence of dielectric characteristics on the EDM of titanium alloy." The International Journal of Advanced Manufacturing Technology 72.5-8 (2014): 979-987.â€

[8] Sadagopan, P., and B. Mouliprasanth. "Investigation on the influence of different types of dielectrics in electrical discharge machining." The International Journal of Advanced Manufacturing Technology 92.1-4 (2017): 277-291.â€

[9] Pandey H, Dhakar K, Dvivedi A, Kumar P (2016) parametric investigation and optimization of near-dry electrical discharge machining. Journal of Scientific & Industrial Research 74:508–51.

[10] Niamat, M., Sarfraz, S., Aziz, H., Jahanzaib, M., Shehab, E., Ahmad, W., & Hussain, S. (2017). Effect of Different Dielectrics on Material Removal Rate, Electrode Wear Rate and Microstructures in EDM. Procedia CIRP, 60, 2-7.†

[11] Sultan T, Kumar A, Gupta RD. Material Removal Rate, Electrode Wear Rate, and Surface Roughness Evaluation in Die Sinking EDM with Hollow.

[12] Muthuramalingam T, Mohan B. Influence of discharge current pulse on machinability in EDM. Mater Manuf Process 2013; 28(4): 375-380.

[13] Lin YC et al. Machining characteristics and optimization of machining parameters of SKH 57 high-speed steel using electric-discharge machining based on the Taguchi method. Mater Manuf process 2006; 21(8): 922-929.

[14] B. Ekmekic: Metall. Mater. Trans. B Process Metall. Mater. Process Sic., 2009, vol. 40, pp. 70-81.

[15] Zhang, Yanzhen, et al. "Influence of dielectric type on porosity formation on electrical discharge machined surfaces." Metallurgical and Materials Transactions B 43.4 (2012): 946-953.†

[16] Nguyen, Minh Dang, Mustafizur Rahman, and Yoke San Wong. "An experimental study on micro-EDM in low-resistivity deionized water using short voltage pulses." The International Journal of Advanced Manufacturing Technology 58.5-8 (2012): 533-544.â€

[17] Chakraborty, S., V.Dey, and S. K. Ghosh. "A review on the use of dielectric fluids and their effects in electrical discharge machining characteristics." Precision Engineering 40(2016):1-6.†

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