Synthesis of NiWP coated diamonds particles with enhanced mechanical and anti-corrosion property for diamond wires of the sawing process

Abstract In this study, NiWP ternary shell layer on diamond powder was synthesized by electroless deposition method. The characteristics of thin films with different deposition parameters such as bath compositions, temperature, and pH were studied. The composition of tungsten in NiWP thin films could be varied by the concentration of sodium tungstate, and it was saturated as ~24 wt%. With the decrease of phosphorous content, crystal structure was changed from amorphous to polycrystalline by the addition of sodium tungstate in the electrolyte. The incorporation of tungsten into NiP films could improve the hardness and the corrosion resistivity, which is critical for utilizing the diamond powders as a sawing applications. From systematic investigations, the optimal electroless deposition of NiWP on the diamond powders was obtained at 70 °C with pH 9.