钛合金Ti6Al4V表面Mo-N改性层的摩擦性能研究

Friction and Wear Behavior of Mo-N Diffusion Layer on Ti6Al4V Alloy Surface

采用钼-氮离子共渗与离子渗钼后再氮化2种工艺,在钛合金Ti6Al4V表面形成均匀致密的钼氮合金渗层。实验结果表明,2种工艺形成的表面合金层表面硬度都有大幅度提高,其中渗钼后氮化的硬度Hk0.1为16810MPa,钼-氮共渗Hk0.1为18040MPa。渗钼后氮化合金层主要为MoN相,而钼-氮共渗合金层主要为Mo2N相。干摩擦条件下,球盘磨损试验表明,渗钼后氮化工艺更好地改进了钛合金Ti6Al4V耐磨性,降低比磨损率3个数量级。

Tow kinds of Mo-N alloyed Iayers were fabricated on the surface of Ti6Al4V alloy by Xu-Tec process. One process was Mo-diffusing with nitriding simultaneously,and the other is nitriding after Mo-diffusing. This paper investigated their friction and wear behaviors against a polished 2100 steel counterbody ball under ball-on-disc test condition.It has been found that both the two Mo-N diffusion layers have excellent wear-resistant hehavior in sliding hut their friction coefficient increases slightly.The war rate for Mo-diffusing with simullaneous nitriding 400 times less than Ti6Al4V and 1080 times less for nitriding after Mo-diffusing.