Etude tribologique des revêtements en couches minces sur les pièces soumises aux frottements et à l’usure

Abstract

This work is a tribological study that tend to give technical solution of the oil and gas valves that suffer from surface failures; through coatings and thin films using different processes: thermal spraying, Plasma Immersion Ion Implantation (PIII) nitriding and Physical Vapour Deposition (PVD). Thermal spraying and post spray vacuum annealing give massive coatings with high hardness (13.9 GPa) and corrosion resistance (0.069 mpy). PIII nitriding increase the hardness of the coating surface (16.4 GPa) and the W-Ti-N thin film deposited by PVD improve the tribological behaviour of the obtained multilayer system (hardness of 22.3 GPa, friction coefficient of 0.14 and a wear rate of 7.55∙10-8 mm3/N∙m).