Volume 9 Issue 1 ( March 2022 )


Surface Integrity of RBD Palm Oil as a Bio Degradable Oil Based Dielectric Fluid on Sustainable Electrical Discharge Machining (EDM) of AISI D2 Steel

Aiman Supawi, Said Ahmad, Nurul Farahin Mohd Joharudin, Fazida Karim


In electrical discharge machining (EDM), material removal occurs through successive electrical discharges between an electrode and a workpiece in the presence of dielectric fluid. A proper selection of dielectric medium is an important consideration for EDM efficiency, as dielectric fluid plays a significant role in any EDM activity. The aim of this research is to discover the usability of Refined, Bleached and Deodorized (RBD) palm oil based dielectric fluid (cooking oil) on the EDM operation of AISI D2 steel using a copper electrode relative to conventional dielectric fluid in term of surface integrity which covers the analysis of a recast layers (RL ) and microharderness (MH) at deeper layer of the machined surface. Peak current, Ip 5A to 12A, and pulse duration, ton 50μs to 150μs were selected as the main parameters. The result shows the lowest and highest RL was recorded at Ip =6A and ton=50µs, which is 7.64μm and Ip =12A and ton =150µs which is 15.50μm for RBD palm oil. While the lowest and highest RL for kerosene is 10.60μm and 17.00μm at the same parameter as RBD palm oil, respectively. The thinness of RL in the EDM process produces better machining performance. The thickness RL for both dielectric fluids were increased with an increase of Ip and ton . The MH on the RL is much higher when compared to the base material. In the case of surface integrity, the bio-degradable dielectric fluid based on dielectric fluid, RBD palm oil, shows considerable potential for its success in AISI D2 steel EDM machining.

Keywords: rbd palm oil; electrical discharge machining; AISI D2 steel