Microstructure and properties of tin-cobalt nanocomposite coatings reinforced by titanium dioxide nanoparticles

Sn?Co binary alloy coatings are widely used as substitutes for chromium coatings in many aspects of modern industry. In this research, TiO2 nanoparticles were incorporated into the matrix of Sn?Co coatings aiming to enhance coating performance. The microstructure, mechanical properties and corrosion resistance of Sn?Co?TiO2 coatings were investigated systematically. The results found that the content of TiO2 nanoparticles imposed significant effects on the microstructure and properties of Sn?Co TiO2 coatings. Comparing with Sn?Co film, Sn?Co?1 g l(?1) TiO2 coating has an increased microhardness of ?409 HV. Also, the corresponding wear resistance and corrosion behavior of coatings were enhanced as well. The strengthening mechanism could be attributed to the structural evolution of coatings along with the addition of TiO2 nanoparticles. The relationships among TiO2 nanoparticles concentration, microstructure and properties were discussed in detail.