Ti6Al4V合金的磨损行为和磨损机制

Wear and Friction Characteristics of Ti6Al4V Alloy

采用销-盘式高温磨损试验机对Ti6Al4V合金在20～400℃进行干滑动摩擦磨损实验,研究了Ti6Al4V合金的磨损行为并探讨了其磨损机制。结果表明:25℃时,合金的磨损量随载荷的增加而逐渐升高;200℃时的磨损量略高于25℃,但当载荷高于200N时,磨损量急剧升高。当温度为400℃、载荷在50～100N时,磨损量降低且达到最低值,随后在100～200N之间磨损量略有升高,200N以后磨损量急剧升高。25℃和200℃下磨损机制主要为黏着磨损和磨粒磨损;400℃、载荷为100～200N时磨损机制为氧化轻微磨损。研究发现,磨损过程中形成机械混合层,当400℃,载荷为100～200N时机械混合层中出现氧化物Ti8O15和TiO2,这样硬的机械混合层具有显著地减磨作用。

The wear and friction characteristics of Ti6Al4V alloy were studied. The results show that the wear rate at 25℃ gradually increases with the increase of load. At 200℃, the wear rate under low loads is slightly higher than that at 25℃ , and the wear rate starts to increase rapidly above the load of 200N. At 400℃ , wear rate decreases under the load of 50 - 100N, slightly increases under the load of 100 -200N, and rapidly increases above 200N. The main wear mechanisms at 25℃ and 200℃ are adhesive wear and abrasive wear respectively. At 400℃ ,oxidative mild wear is prevailed under the load of 100 -200N. It is found that mechanic mixing layer is formed on worn surfaces. When the load of 100 -200N is applied at 400℃ , tribo-oxides appear on worn surfaces. In this case, the hard mechanic mixing layer possesses an obvious wear-reduced role.