Surface Modification by EDM with Nickel Powder Mixed Fluid

Surface modification of aluminum bronze used for shell mold core metal was experimentally investigated by EDM with nickel powder mixed fluid, in order to form nickel layer on EDMed surface for higher wear resistance to shell sand abrasion. Experimental analyses made it clear that the resolidified layer contained nickel richly and the thickness of the layer became larger and uniform with an increase of nickel powder concentration in the machining fluid. The EDMed surface with nickel powder mixed fluid was harder and smoother than that with kerosine type fluid. Moreover, it showed higher wear resistance in sand abrasion test.