Dissipated energy and fretting damage in CoCrAlY-MoS2 coatings

This paper describes fretting wear behaviour of low friction CoCrAlY–MoS2 coatings on titanium alloy substrates in terms of dissipated energy and friction coefficient. Experimental characterisation was achieved by measuring the friction coefficient vs fretting cycles, or slid distance. Test results were analysed using exponential evolution functions for fretting damage. Dissipated energy was derived, and predicted and measured values compared. Quantitative evaluation of the fretting damage was performed by measuring substrate area emerged. Results show that the friction coefficient evolution rate of CoCrAlY–MoS2 coating correlates well with the damaged area fraction and the accumulated dissipated energy.