WEAR FRETTING BEHAVIOR OF THICK HA ANODIZING ALUMINA LAYER

Abstract

It is common to coat a substrate, or provide surface treatment to engineering materials with good mechanical proprieties and resistance against corrosion but poor tribological proprieties as aluminium alloys. The surface control at a rudimentary level is reached through a simple parameter such as the roughness R_a. In the present paper, very thick alumina layers were carried out by hard anodisation (HA) in order to determine the wear friction behavior with a plansphere contact (Al-Al₂0₃/steel) configuration. Profile hardness shows heterogeneous proprieties through layer thickness. All wear fretting tests were carried out at room temperature under Gross slip régime. The mean friction coefficient varies around the value 1.1 and the evolution of the diameter against cumulated energy shown a net increase. The observations by optical microscopy and SEM of the fretting scars at the contact indicate an adhesion wear phenomena. In addition the heterogeneity in hardness creates a high stress in the thick layer and represents the principal cause of the superficial plastic deformation and formation of surface cracks.R_a

http://dx.doi.org/10.5755/j01.mech.17.4.578