| Popis: |
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 (R_L) and microharderness (MH) at deeper layer of the machined surface. Peak current, I_p 5A to 12A, and pulse duration, ton 50μs to 150μs were selected as the main parameters. The result shows the lowest and highest R_L was recorded at I_p=6A and ton=50μs, which is 7.64μm and I_p=12A and ton=150μs which is 15.50μm for RBD palm oil. While the lowest and highest R_L for kerosene is 10.60μm and 17.00μm at the same parameter as RBD palm oil, respectively. The thinness of R_L in the EDM process produces better machining performance. The thickness R_L for both dielectric fluids were increased with an increase of I_p and ton. The MH on the R_L 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. |
