Tribological Properties of Mo-N Hard Coatings on Ti6A14V by Double Glow Discharge Technique

Mo-N hard coatings on Ti6AI4V were formed using double glow discharge technique. The fundamental coating properties, such as the phase, hardness and elastic modulus were investigated. The tribological performances of the coatings in dry wear condition were studied by means of ball-on-disc wear machine. The experimental results showed that the thickness of the Mo-N hard coating was about 10 μm. The coating was single fcc γ-Mo2N phase with (200) preferred orientation. The hardness and the elastic modulus of the coating was 13.80 GPa and 261.65 GPa respectively. The surface treatment enhanced the hardness and elastic modulus of the surface of Ti6AI4V base greatly. With GCr15 slider ball, the friction coefficient of the Mo-N hard coating was in the range of 0.56-0.65 at the steady state. Though the coating did not show friction reducing effect, it improved the wear resistance of Ti6AI4V greatly.