Properties of Micro-Arc Oxidation Coatings on 5052 Al Alloy Sealed by SiO2 Nanoparticles

Micro-arc oxidation (MAO) treatment can effectively improve the wear resistance, corrosion and mechanical strength of aluminum alloy substrates. Improving porous structure MAO film sealing pores is a significant research issue. In this study, 5052 was carried out in silicate electrolytes. The films were sealed with different concentrations SiO2 nanoparticles. effects nanoparticle content on films’ microstructure, properties, performance systematically investigated. When adding nanoparticles to electrolytes, particles deposited at micropores film, which could seal significantly its resistance. resistance properties optimal 5.0 g/L addition. Compared unsealed current density rate decreased from 1.24 × 10?9 A/cm2 1.47 10?5 mm/a 7.78 10?10 9.15 10?6 mm/a, respectively. Moreover, average friction coefficient 0.606, ~19.3% lower than that substrate 3.3% for film.