A combined friction energy and tribo-oxidation formulation to describe the high temperature fretting wear response of a cobalt-based alloy

Abstract

Abstract A cobalt-based superalloy (HS25) versus alumina contact was subjected to gross slip fretting using a cross-cylinders configuration and various tribological conditions. The present study focuses on the modelling of different wear mechanisms which mainly depend on the operating temperature. Wear below a threshold temperature (150\u202f°C) is severe whereas a protective oxide layer is formed above the temperature transition. At low temperature, the wear process was found to be controlled by a continuous action of the oxidation of the surface and the abrasion of the latter. Wear mechanism was also showed to be strongly dependent on temperature, sliding amplitude and frequency [1] . An energetic wear law was developed to formalize the oxidative-abrasive wear mechanism displaying a good correlation with experiments. Above the threshold temperature, the oxidative-abrasive phenomenon is not operating anymore and a protective glaze layer is formed at the interface. A tribo-sintering approach is proposed to predict the glaze layer formation for various tribological parameters. Moreover, the glaze layer protective effect was taken into consideration in the wear formulation by considering that only the friction energy dissipated before the glaze layer creation needs to be integrated. The proposed formulation showed a very good prediction of wear volumes from ambient to high temperature (600\u202f°C).