Electrical discharge coating using WS2 and Cu powder mixture for solid lubrication and enhanced tribological performance

In the present study, solid-lubricating surfaces were produced through electrical discharge process using green compact electrodes prepared from tungsten disulphide (WS2) and copper (Cu) powder mixture. The effect of experimental parameters such as duty factor, peak current, and powder mixture ratio was investigated on wear behavior and surface integrity of coating. The FESEM images indicated fewer pores with powder mixture ratio WS2:Cu/60:40, peak current 7A and duty factor 50%. The XRD profile of coating showed the various peaks of W, WS2, Cu and Cu2S. Micro-hardness of the solid-lubricating coating reduced from 180HV (workpiece) to a minimum value of 44.11HV (coating). Further, Pin-On-Disc wear test showed significant reduction in wear from 95.75 mu m (parent surface) to the least value of 6.71 mu m (coated surface).