热力耦合下TC4合金微动磨损行为影响的研究

为了研究TC4合金在300℃和500℃下的微动磨损行为，利用扫描电子显微镜和激光共聚焦显微镜分别表征表面磨痕形貌、磨损体积和磨痕轮廓，探究两种温度中TC4合金不同接触载荷作用下的微动磨损机制。结果表明： 磨损体积与接触载荷呈现正相关的关系，而摩擦系数和磨损率则呈现负相关的关系。两种温度下的无润滑微动摩擦磨损过程中，小载荷作用时磨损形式表现为氧化磨损和磨粒磨损；大载荷作用时磨损形式为氧化磨损和黏着磨损。与300℃相比，500℃时合金接触表面塑性变形严重，摩擦系数小，氧化磨损加剧，疲劳裂纹扩展严重。TC4合金高温环境中微动磨损机制为黏着磨损、磨粒磨损、氧化磨损和疲劳磨损，其中氧化磨损在TC4合金高温微动磨损中占据主导地位。

Effect of thermal mechanical coupling on fretting wear behavior of TC4 alloy

Fretting wear behavior of TC4 alloy was studied under various contact loads at 300℃ and 500℃. Surface wear track morphology, wear volume and wear track profile were characterized by scanning electron microscope and laser confocal microscope to explore the fretting wear mechanism of TC4 alloy under different contact loads in the two temperatures. The results showed that the wear volume and the contact load present a positive correlation, while the friction coefficient and the wear rate present a negative correlation. In the process of lubrication fretting wear at two temperatures, the form of wear is oxidative wear and abrasive wear under the small load and oxidative wear and adhesive wear under the large load. Compared with 300℃, the surface exhibits larger plastic deformation, less friction coefficient, more intensifying oxidative wear and more extending fatigue cracks at 500℃. The fretting wear mechanism of TC4 alloy in high temperature environment involves adhesive wear, abrasive wear, oxidative wear and fatigue wear, in which the dominant function is oxidative wear.