Effect of Morphological and Microstructural Variations on the Properties of Electroless Nickel Boron Coatings

Electroless nickel boron (ENB) coatings have attracted widespread attention due to their high wear resistance and hardness. However, the effects of surface morphology and microstructure properties on the hardness, friction, and corrosion performance of ENB coatings are not fully known. Herein, ENB coatings with different surface morphologies and microstructures were produced using baths with various reducing agent (NaBH4) concentrations and characterized. According to the scanning electron microscopy examinations, the morphology and distribution of grains change dramatically subject to the NaBH4 ratio. For 1.0 wt% NaBH4, ENB coating has the smoothest surface and hydrophilic behavior. The coatings with low surface roughness exhibit a low coefficient of friction. The ENB containing 1.0 wt% NaBH4 has the highest corrosion resistance in the 3.5 wt% NaCl medium. In conclusion, adjusting the surface and morphological properties can enable ENB coatings in truck bed liners, trailers, farm equipment, etc.