Ti-6Al-4V合金热氧化涂层的高温磨损行为研究

Research on Elevated-temperature Wear Behavior of Thermal Oxidation Coating on Ti-6Al-4V Alloy

摘要:

通过热氧化/真空扩散处理在Ti-6Al-4V合金表面制备氧化涂层,采用高温磨损试验机对涂层在400 ℃空气中进行干滑动摩擦磨损试验,研究了涂层的高温磨损行为和机制。结果表明：Ti-6Al-4V合金经氧化/扩散后表面形成氧化物涂层,厚度达250 μm。相比于未处理的材料,氧化物涂层的磨损失重非常小,高温耐磨性显著提高。磨损表面均形成摩擦氧化物层,涂层的高耐磨性可归功于硬化的陶瓷涂层与具保护作用的摩擦层的共同作用。主要磨损机制为剥层磨损。

Abstract:

Ti-6Al-4V alloy was thermal oxidized and subsequently vacuum diffused to prepare an oxidation coating. Dry sliding wear tests of the coating were performed at 400 ℃ in air on a high-temperature wear tester. The elevated-temperature wear behaviors and mechanism of coating were studied. The results show that the oxidation coating with a thickness of 250 μm was produced on Ti-6Al-4V alloy. The wear losses of oxidation coating were extremely low, compared with uncoated materials, its elevated-temperature wear resistance was noticeably improved. Tribo-oxide layers were always found to form on worn surfaces. The high wear resistance of coating could be ascribed to the integrated function of the hardened ceramic coating and protective tribo-layer. The predominant wear mechanism was delamination wear during dry sliding.