Preparing Porous Diamond Tools Via Electrophoretic Deposition Of Diamond Powder On Foam Nickel Substrate

In this paper, porous diamond grinding tool was prepared via electrophoreticdeposition (EPD) of diamond micro-power and followed electroless plating Ni on a nickelfoam substrate. The influences of the EPD and the plating conditions on the diamondcoatings were investigated. The morphology of the coating was characterized by fieldemission microscope(FE-SEM). The bending strength and the wear resistance ratio of thesamples were measured.The EPD results show that diamond micro-powder was deposited on foam nickelanode at the electric fields of3~8V/cm. The weight increment of EPD layer increasedwith the field intensity and EPD time. However, when the field intensity was beyond6V/cm or the time was larger than20min, the EPD velocity did not increase any moreowing to electric field shielding. A uniform diamond layer on porous foam nickel substratewas obtained at6V/cm after depositing for20min. The FE-SEM photos reveal that the Nicoating obtained by electroless plating had a smooth surface and a bright appearance at thepH of8and the temperature of70℃.The volume ratio of diamond micro-power and Ni can be adjusted by controlling theconditions of the EPD and the electroless plating processes. The diamond micro-powercould be well hold on the substrate when the volume ratio of diamond micro-power and Niin coating was about1:1. Diamond micro-powder easily dropped from the substrate withlittle Ni coating, on the contrary, diamond particles can not protrude above the substratewith too thick Ni coating.The grinding tests show that the prepared diamond-Ni/foam nickel composite had agood grinding performance. It can be used as porous diamond grinding tool.