LAUSR

Abstract Surface treatments via plasma nitriding process have been applied on Co based alloys due to the surface enhancement on their tribological properties. Herein, the surface characteristics to apply a thin Ti coating on biocompatible CoCr ASTM F75–18 alloy samples post-plasma nitriding treatment to improve the mechanical and tribological properties were investigated. A single nanolayer Ti coating was deposited by thermal evaporation technique and posterior plasma nitriding process using three temperatures ranging from 450 °C to 550 °C, considering two processing time of 3 h and 5 h. The samples were characterized using metallographic techniques, energy dispersive spectroscopy, scanning electron microscopy, X-ray diffraction, atomic force microscopy, nanohardness tests under cyclic loads of 20 Hz, 50 Hz and 100 Hz using a load of 350 μN and roughness. Friction and wear characteristics were investigated on pin-on-disc tribometer under dry and lubricated sliding condition. The results showed that Ti coatings post-nitriding process have a beneficial effect on the friction and wear resistance of CoCr alloy depending on the elastic modulus and hardness as well as the contact stiffness under cyclic loads as function of increase the thermal process.