Characteristics of Al alloy surface after EDC with sintered Ti electrode and TiN powder additive

Electrical discharge coating (EDC) performs not only machining but also surface modification of workpiece by changing the polarity of the electrode and dielectric medium. As a candidate of metal bipolar plate in proton exchange membrane fuel cell application, machined Al alloy needs surface coating to overcome its poor corrosion resistance. The goal of this study was to investigate the coating characteristics of 6061-T6 aluminum (Al) alloy machined using titanium (Ti)-sintered electrodes in wet and dry EDC. The results show that in wet EDC using cathodic T-8 sintered electrode, both material removal rate (MRR) and tool wear rate (TWR) were kept reasonably low. Discharge current ( I p ) and pulse duration ( T on ) are the main determinants of the morphology of the EDCed Al alloy surface. The appropriate parameters for wet EDC are found to be 1 A