Reduction of pores and wear rate in electrical discharge coating by using hBN nano powder

An attempt is made to reduce the porosity in electrical discharge coating of Cu+M oS2 powder by the application of hBN nanopowder in a green compact tool. In the present study, the mild steel surface is modified by depositing layer of coating made of copper, molybdenum disulfide, and hexagonal boron nitride powder with the help of electrical discharge coating (EDC) process. Die Sink electrical discharge machine is being used in reverse polarity to deposit a coating layer above substrate surface. The layer is deposited with the help of green compact electrode made of Cu/M oS2/hBN powder, which is made inside the hot mounting press machine at specific parameters. The thickness of the layer has been controlled by varying machine parameters such as peak current and powder mixing ratio. Further, morphology and tribological properties of Cu/M oS2/hBN is compared with Cu/M oS2 coating. FESEM image shows the morphology of the coating layer with negligible number of pores with mixing ratio of Cu/M oS2/hBN:40/30/30 at peak current of 7 A and 50% duty factor. X- ray diffraction test depicts the evidence of Cu, MoS2, BN compounds. M oreover, the dry sliding wear test reveales improvement in tribological behavior of parent material after coating.