Microstructure and properties of Ni–B–TiO₂nano-composite coatings fabricated by electroless plating

Abstract

Ni–B coatings are used in automotive, aerospace, petrochemical, and electronic industries due to their high hardness, good wear and corrosion resistance. In this research, nano-composite Ni–B–TiO2 coatings are deposited on mild steel samples by electroless plating method. A systematic study of Ni–B–xTiO2 coatings with different TiO2 concentrations (x = 0–20 g L−1) has been conducted. The coatings are characterised using SEM, XRD, microhardness and wear testers. It is found that the incorporation of TiO2 nano-powder can significantly improve the mechanical properties of Ni–B coatings. The microstructure and mechanical properties of the electroless deposited Ni–B–TiO2 nano-composite coatings is strongly affected by the amount of TiO2 addition. The correlation of the TiO2 concentrations with the microstructure and properties of coatings are discussed.