An experimental investigation of adhesive wear extension in fretting interface: Application of the contact oxygenation concept

This paper investigates the transition from abrasive to adhesive wear in gross-slip fretting assuming contact oxygenation concept which suggests that adhesion appears in the inner part of the interface if the di-oxygen partial pressure is below a threshold value. In the lateral sides, where di-oxygen molecules are sufficient, oxidation and abrasion prevail. To assess this phenomenon, 34NiCrMo16 flat-on-flat contacts are tested. Contact oxygenation is quantified using the "oxygen-distance, d(O)" parameter defined as the averaged width of the external abrasion corona. Confirming this concept, d(O) decreases with contact pressure and frequency but remains constant versus sliding amplitude, fretting cycles and contact area. d(O) evolution is formalized using a power law formulation which allowed predicting wear transitions for plain and macro-textured surfaces.