Machining and Surface Characteristics of AISI 304L After Electric Discharge Machining for Copper and Graphite Electrodes in Different Dielectric Liquids

S. Anjum, M. Shah, N. A. Anjum, S. Mehmood, W. Anwar

Abstract


In Electric Discharge Machining (EDM), the thermal energy used for material erosion depends on the intensity of electric sparks, the thermal conductivities of electrode material and the dielectric liquid. In this paper, the effect of EDM on AISI 304L steel is studied using copper and graphite electrodes and distilled water and kerosene oil as dielectric liquids. Material Removal Rates (MRR), Tool Wear Rates (TWR) and surface conditions are calculated for four different combinations with the two electrode materials and the two dielectric liquids. These investigations are carried out at different pulse currents. Machined surfaces are evaluated by morphological studies, energy dispersive spectrographs (EDS) and white layer thickness using Scanning Electron Microscopy (SEM). It is found that a transfer of carbon takes place from the kerosene oil and the graphite electrodes into the machined surface which alters the metallurgical characteristics, depending on the electrical and thermal conductivities of the electrode material and the dielectric liquid.


Keywords


electric discharge machine; material removal rate; electrode wear rate; white layer

Full Text:

PDF

References


K. H. Ho, 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

S. Mehmood, M. Shah, R. A. Pasha, S. Khushnood, A. Sultan, "Influence of electric discharge machining on fatigue limit of high strength aluminum alloy under finish machining", Journal of the Chinese Institute of Engineers, Vol. 40, No. 2, pp. 118-125, 2017

S. Mehmood, R. A. Pasha, A. Sultan, "Effect of electric discharge machining on material removal rate and white layer composition", Mehran University Research Journal of Engineering & Technology Vol. 36, No. 1, pp. 45-54, 2015

C. H. Che Haron, J. A. Ghani, Y. Burhanuddin, Y. K. Seong, C. Y. Swee, "Copper and graphite electrodes performance in electrical-discharge machining of XW42 tool steel", Journal of Materials Processing Technology, Vol. 201, No. 1-3, pp. 570-573, 2008

Y. H. Jeong, B. K. Min, "Geometry prediction of EDM-drilled holes and tool electrode shapes of micro-EDM process using simulation", International Journal of Machine Tools and Manufacture, Vol. 47, No. 12–13, pp. 1817-1826, 2007

M. Sohani, V. Gaitonde, B. Siddeswarappa, A. Deshpande, "Investigations into the effect of tool shapes with size factor consideration in sink electrical discharge machining (EDM) process", The International Journal of Advanced Manufacturing Technology, Vol. 45, No. 11-12, pp. 1131-1145, 2009

N. Pellicer, J. Ciurana, T. Ozel, "Influence of process parameters and electrode geometry on feature micro-accuracy in electro discharge machining of tool steel", Materials and Manufacturing processes, Vol. 24, No. 12, pp. 1282-1289, 2009

A. G. Jaharah, C. G. Liang, S. Z. Wahid, M. N. Ab Rahman, C. H. Che Hassan, "Performance of copper electrode in electical discharge machining (EDM) of aisi h13 harden steel", International Journal of Mechanical and Materials Engineering Vol. 3, No. 1, pp. 25-29, 2008

B. Bhattacharyya, S. Gangopadhyay, B. R. Sarkar, "Modelling and analysis of EDMED job surface integrity", Journal of Materials Processing Technology, Vol. 189, No. 1-3, pp. 169-177, 2007

A. A. Khan, "Electrode wear and material removal rate during EDM of aluminum and mild steel using copper and brass electrodes", The International Journal of Advanced Manufacturing Technology, Vol. 39, No. 5-6, pp. 482-487, 2007

F. L. Amorim, W. L. Weingaertner, "The behavior of graphite and copper electrodes on the finish die-sinking electrical discharge machining (EDM) of AISI P20 tool steel", Journal of the Brazilian Society of Mechanical Sciences and Engineering, Vol. 29, No. 4, pp. 366-371, 2007

S. Chakraborty, V. Dey, S. K. Ghosh, "A review on the use of dielectric fluids and their effects in electrical discharge machining characteristics", Precision Engineering Vol. 40, pp.1-6, 2015

Y. Zhang, Y. Liu, R. Ji, B. Cai, "Study of the recast layer of a surface machined by sinking electrical discharge machining using water-in-oil emulsion as dielectric", Applied Surface Science, Vol. 257, No. 14, pp. 5989-5997, 2011

B. Ekmekci, O. Elkoca, A. Erman Tekkaya, A. Erden, "Residual stress state and hardness depth in electric discharge machining: de-ionized water as dielectric liquid", Machining Science and Technology, Vol. 9, No. 1, pp. 39-61, 2005

S. Mehmood, A. Sultan, N. A. Anjum, W. Anwar, Z. Butt, "Determination of residual stress distribution in high strength aluminum alloy after EDM", Advances in Science and Technology Research, Vol. 11, No. 1, pp. 29-35, 2017

F. N. Leão, I. R. Pashby, "A review on the use of environmentally-friendly dielectric fluids in electrical discharge machining", Journal of Materials Processing Technology, Vol. 149, No. 1-3, pp. 341-346, 2004

S. Chen, B. Yan, F. Huang, "Influence of kerosene and distilled water as dielectrics on the electric discharge machining characteristics of Ti–6A1–4V", Journal of Materials Processing Technology, Vol. 87, No. 1, pp. 107-111, 1999

P. Sharma, S. Singh, D. R. Mishra, "Electrical discharge machining of AISI 329 stainless steel using copper and brass rotary tubular electrode", Procedia Materials Science, Vol. 5, pp. 1771-1780, 2014

B. Ekmekci, "Residual stresses and white layer in electric discharge machining (EDM)", Applied Surface Science, Vol. 253, No. 23, pp. 9234-9240, 2007

A Descoeudres, Characterization of electrical discharge machining plasmas, Fedral Institute of Technology, Lausanne, Switzerland, 2006




eISSN: 1792-8036     pISSN: 2241-4487