Sliding wear behaviour of plasma electrolytic oxidation coating on pure aluminium

In previous studies sliding wear behaviour of plasma electrolytic coating on pure aluminium was investigated. The effects of treated times, current density, current frequency of plasma electrolytic oxidation on the surface microstructural, mechanical and sliding wear behaviour of the ceramic coatings are conducted. Further investigations are reported regarding the sliding wear behaviour and mechanical properties of this treatment in sliding wear tests against Al2O3 sand paper counter faces using a low frequency reciprocating sliding diameter of 10 mm at a load of 10 N. Scanning electron microscopy was employed to assist in the evaluation of the wear behaviour and failure mechanisms. It is shown that the ceramic coating, consisting primarily of micro-plasma sintering ceramic layer and micropores, provide improved wear resistance and enhanced load-bearing capacity for low-friction coating. The primary sliding wear mechanism observed is one of mild asperity deformation and polishing and, in extreme cases, localized delamination of the ceramic coating.