Surface Modification of AISI 304 Stainless Steel by Electrical Discharge Coating Using Powder Suspension Method

Abstract

Electro Discharge Machining (EDM) is an extensively used non-traditional material removal process to machine complicated geometrical parts and extremely hard materials that are otherwise very challenging to machine by conventional machining processes. A very special aspect of this process apart from machining is surface modification by depositing material from tool electrode to workpiece. The present study examines the method of depositing TiC and (TiC+TiB2) on AISI 304 stainless steel substrate by suspending titanium and boron carbide powders in dielectric fluid. Reverse polarity mode (tool positive and workpiece negative) was employed by using copper as tool electrode. The effect of parameters, peak current (Ip), pulse on time (Ton), voltage (V) and duty factor (Tau) during the process on surface roughness, micro hardness and wear rate has been studied. Micro structure of the surface was examined using scanning electron microscopy (SEM) and compounds present on the surface were evaluated by X-Ray diffraction (XRD) technique.