The Performance of RBD Palm Oil Dielectric Fluid in Comparison with Kerosene in Electrical Discharge Machining (EDM) Process

Abstract

In machining industries, it is desirable to ensure that maximum material removal rate (MRR) can be obtained in order to meet industrial needs. The selection of dielectric fluid is considered as one of the factors that can affect electrical discharge machining (EDM) performance. However, the sustainability of EDM is questioned when the conventional dielectric used is harmful to the environment and people due to its toxic emission. One of the ways to maintain the sustainability of EDM is to use vegetable oil as dielectric fluid to overcome the concern as vegetable oil is known for its environmentally friendly and bio-degradability. This research was to study the effect of refined bleached and deodorized (RBD) palm oil on MRR and surface topography of AISI D2 steel, and then compared with kerosene at constant value of discharge current of 12 A, with pulse on and off time 150 and 50 µs, respectively. Besides, viscosity of the RBD palm oil and its relationship with the MRR after the continuous work also observed. Trials were carried out by cutting AISI D2 using copper electrode with 1.5 mm cutting depth and repeated for 50 trials in the same dielectric fluid, RBD palm oil. The samples of oil were taken alternately, and the viscosities of the oil were measured. The result shows the lowest and highest MRR was recorded at 6th trial which is 12.46 mm3/min and 10th trial which is 14.76 mm3/min. The lowest and highest value of viscosity is at 22nd trial which is 59.80 cSt and at 28th trial which is 64.80 cSt. Some trial has been conducted by using kerosene as the benchmark for this study. The selected workpieces were being taken for surface topography study by using Scanning Electron Microscope (SEM). The outcome of this research shows that the MRR values and viscosity is fluctuated. However, the values of RBD palm oil are higher compared to kerosene. The MRR values increases when the viscosities decrease and the surface topography become rougher at the end of trials.KeywordsElectrical discharge machining (EDM)Bio-degradable oilAISI D2 steelRBD palm oil