TC4合金在不同环境介质中的磨损行为及磨损机制研究

Wear Behavior and Mechanism of TC4 Alloy in Different Environmental Media

采用MPX-2000型销盘式摩擦磨损试验机,研究了TC4合金在空气、纯水和模拟海水环境下与GCr15轴承钢对磨时的磨损行为和磨损机制,评价不同环境介质对TC4合金耐磨性的影响。结果表明:TC4合金在模拟海水中的磨损率始终最高,明显高于其在纯水和空气中的磨损率,且在模拟海水中磨损时TC4合金腐蚀速度大大加快,可见腐蚀和磨损之间存在明显的相互促进作用。TC4合金在模拟海水中形成的润滑膜可以明显降低摩擦系数,因而不同工况下模拟海水中的摩擦系数始终较低,纯水中的摩擦系数略高于海水,而空气中的摩擦系数在0.50及0.75 m·s-1,1.02 MPa时明显高于纯水和海水,在0.75 m·s-1,2.55 MPa时反而略低于纯水和模拟海水。TC4合金在空气中的磨损机制为氧化磨损并伴有一定程度的磨粒磨损和粘着磨损;在纯水中的磨损机制为磨粒磨损;而在模拟海水中则为疲劳磨损和磨粒磨损混合作用机制。

Sliding wear tests were performed for TC4 alloys against GCrl5 steel in atmosphere, pure water, and simulated seawater on a pin-on-disk wear tester （ MPX-2000 type）. The wear behaviors and the mechanisms of TC4 alloy were investigated and the effect of different environmental media on wear resistance of TC4 alloy was evaluated. The results showed that the wear rate of TC4 alloy in simulated seawater was obviously higher than that in pure water and atmosphere. Additionally, when worn in simulated seawater, the corrosion speed of TCA alloy was accelerated, which demonstrated that the wear and the corrosion mutually reinforced. The lubrication surface film formed in simulated seawater could reduce the friction coefficient effectively. Thus, TC4 alloy had relatively low friction coefficients in simulated seawater in various conditions. While the friction coefficients of TC4 alloy in pure water were slightly higher than those in simulated seawater. The friction coefficients in atmosphere were obviously higher than those in simulated seawater and pure water at 0.50 m.s-1 as well as 0.75 m·s-1 and 1.02 MPa, but slightly lower than those in simulated seawater and pure water at 0.75 m·s -1 and 2.55 MPa. The wear mechanism of TC4 alloy in atmosphere was oxidative wear accompanied with some degree of abrasive and adhesive wear. The wear in pure water was typical abrasive wear, whereas in simulated seawater, the wear mechanism changed into the combination of abrasive wear and fatigue wear.