Preparation and Characterization of Ni-diamond Composite Coatings Using Sedimentation Co-deposition Technique Alternative to Conventional Electrodeposition Technique

Abstract

Composite coatings are the techniques involving co-deposition of inert particles with metal/alloy in order to promote the hardness, wear and corrosion resistance of the coatings. Micro crystalline Ni based composite coatings were prepared by conventional electrodeposition method from a Watt's-type electrolyte containing different contents of diamond particles. A modified electro-deposition method called sedimentation co-deposition (SCD) was also used to deposit Ni-diamond composite coatings having more diamond particles in the Ni matrix. Results show that Ni-diamond composite coating prepared by the SCD method contains quite high content of diamond (67-97%) as evidenced by EDS analysis. In contrary the traditional electrodeposition method shows low content of diamond (≈10-20%). The wear and corrosion resistance of the SCD Ni-diamond coating are markedly decreased in comparison to the conventionally electrodeposited coatings.