The microstructure and mechanical properties of Ni–Co–ZrO2 nanocomposite coatings

Abstract

Ni–Co–ZrO2 nanocomposite coatings have been electroplated on mild steel by adding ZrO2 nanoparticles into an Ni–Co plating solution. The microstructure and mechanical properties of nanocomposite coatings were systematically investigated. The results show that the microhardness of Ni–Co–ZrO2 nanocomposite coatings varied significantly with the quantity of ZrO2 nanoparticles. Ni–Co–10 g/L ZrO2 nanocomposite coating exhibited the optimum mechanical properties due to the dispersion strengthening effect. Addition of ZrO2 nanoparticles beyond 10 g/L led to particle agglomeration and caused a porous coating structure, resulting in a deterioration of coating mechanical properties.