Study of abrasive behavior for plasma electrolytic Oxidized Aluminum

Aluminum samples were coated by plasma electrolytic oxidation method to achieve 40µm of alumina oxide on their surface. Abrasive behavior with a rotating wheel-type apparatus has been examined with angular alumina and rounded silica abrasives as a function of test conditions, namely wheel-type rubber wheel or steel wheel and dry or wet environment conditions. Water tends to lubricate the contact between the particles and the sample, especially with small and/or rounded particles and thus the wear rate is reduced. With larger particles, the presence of water still affects wear, in that two-body abrasion may be favored, cutting enhanced and particle embedment reduced. The steel wheel tends to produce more fragmentation of abrasives, but in the wet environment, this is reduced as the lubricated contact with the sample results in lower stresses in the particles. The role of water has been shown to be significant in both the rubber and steel wheel tests and affects particle motion and particle fragmentation depending on particle type, shape and size and thus has a strong effect on wear rates and mechanisms observed. The conditions employed in a test used to simulate service conditions must be carefully chosen so as to mimic the latter conditions as closely as possible and the wet or dry environment is a significant parameter that must be considered.