Experimental Study on the surface modification by Electrical Discharge Process

The creation of modified layer on metals surfaces by the use of new methods is one of the methods in surface engineering which can improve the surface mechanical properties. Electrical discharge process is a new method that can form a modified layer on the metals surface. This paper aims to improve of pure aluminum surface properties through Electrical Discharge process with Monel 400 electrode. In order to design the experiments, pulse on time and pulse current were considered as input parameters. The SEM images indicated that the increase in pulse on time and pulse current can increase the thickness of modified layer. Based on the obtained results, the thickness of improved layer varied between 35 to 75 microns. The results of the EDX analysis indicated the diffusion of copper and nickel to the aluminum surface. Also, the results of microhardness testing of surface layer showed that after Electrical discharge process, the surface hardness has increased and the surface hardness as 35 Vickers has reached more than 400 Vickers.