Pretreatment Effect on the Properties of Electroless Nano - Crystalline Nickel ‎Phosphorous Coating

The influence of mechanical ‎polishing pre-treatments on steel ‎substrates is investigated in terms ‎of microstructure, deposition rate, ‎adhesion, mechanical and ‎corrosion properties of electroless ‎Ni-P nanocoating with 9-10% wt. ‎of P content. XRD analysis of Ni-P ‎coatings demonstrated the ‎nanocrystalline structure of ‎coating with the grain size of 39 ‎nm. Results showed that ‎pretreatment of substrate can ‎affect the microstructure and ‎modularity of coatings. Coatings ‎with homogeneous surface profile ‎and lower nodule boundaries had ‎higher corrosion resistance. The ‎roughness of the substrate had a ‎direct influence on the surface ‎roughness of the substrate which ‎had a direct influence on the ‎surface roughness of the applied ‎coating.‎