TC4合金等离子钼基合金化改性层摩擦磨损性能研究

Study on Wear Properties of Mo-based Plasma Alloying Layer on Ti6Al4V

利用双层辉光等离子渗金属技术在Ti6Al4V(TC4)上制备钼基改性层以提高材料的摩擦磨损性能。对改性层的组织结构元素分布和显微硬度进行了测试,并采用球-盘滑动磨损试验机对渗层进行摩擦磨损性能测试。结果表明:Ti6Al4V合金表面经过渗Mo、W-Mo及W-Mo-N共渗都可以形成致密、均匀的表面合金改性层;通过三种表面改性后,钛合金的表面硬度都有不同程度提高,其中W-Mo-N共渗表面硬度提高最大,达1504 HV。在较短滑动距离内,渗钼改性层摩擦系数最小,W-Mo-N共渗次之,W-Mo共渗最大。随着摩擦的深入,渗钼改性层摩擦系数很快升高,超过W-Mo改性层。渗钼改性层磨损表现为磨粒磨损和粘着磨损,W-Mo和W-Mo-N共渗都降低了材料的粘着现象,W-Mo-N共渗最为显著。

Molybdenum alloying layer and compound layer of W-Mo,W-Mo-N was fabricated on the surface of Ti6Al4V by double glow plasma surface alloying technique.The microstructure distribution and microhardness of compound layer was measured.The wear properties of compound layer were measured by ball-plate slipping wear machine.The results show that the microstructure Ti6Al4V after molybdenum alloying,W-Mo and W-Mo-N alloying is satisfactory.The surface hardness of Ti6Al4V improves at different extent after different treatments,and the microhardness in alloying layer decreases along the depth.The surface hardness of W-Mo-N alloying layer is highest,about 1504 HV,but the hardness of W-Mo-N and molybdenum alloying layer reduces rapidly.In short slip distance,the molybdenum-modified layer gains the smallest friction coefficient among the there alloying layers.As the friction going,the friction coefficient of molybdenum-modified layer increases quickly,even higher than W-Mo alloying layer.Molybdenum-modified layer appears as abrasive wear and adhesive wear.W-Mo and W-Mo-N alloying reduces adherent phenomenon,especially the W-Mo-N alloying.