碳化钨涂层高温摩擦磨损行为

Friction and Wear Behaviors of WC Coatings at High Temperature

采用爆炸喷涂技术制备了碳化钨涂层，利用HT-1000高温摩擦磨损试验机研究了碳化钨涂层高温下摩擦磨损性能，通过扫描电子显微镜和x射线衍射分析了涂层磨损表面形貌、元素分布和相结构．结果表明：碳化钨涂层由雪花片状颗粒堆叠而成，如山地状，结合紧密．定温条件下，摩擦因数随着试验温度升高而减小，试验温度为550℃时，摩擦因数最小；磨损量随着温度升高而增大，550℃时，磨损量由于配副材料的转移出现了负增加．温度低于350℃时，磨损表面具有撕裂、轻微黏着和磨粒磨损痕迹；在550℃时，磨损表面发生了剥落、严重黏着和氧化磨损．连续升温条件下，温度低于300℃时，摩擦因数较小，在350～550℃范围内，摩擦因数波动较大；磨损表面以剥层、黏着和氧化磨损为主．

The WC coatings were prepared by the detonation gun spray technique. Their tribological properties at high temperature were investigated on a HT - 1000 high temperature friction/wear tester. The worn surface and element distribution were analyzed by scanning electronic microscope（SEM）. The phase structure was analyzed by X-ray diffraction. The results show that the WC coatings, heaped by the snowflake-like particles, are of the mountain ground shape. The bonding interface is very tight. Under definite temperature, the friction coefficient gradually minishes with the temperature increase, and the minimum is achieved at 550 ℃. The wear mass loss increases as the temperature increases, with minus addition appearing at 550 ℃ because of the material transfer. The worn surface shows laceration, slight adhesive wear and abrasive wear below 350 ℃. However, the wear mechanism is the combination of desquamation, severe adhesive wear and oxidization wear at 550 ℃. With the continuous temperature increase, the friction coefficient is balanced and lessens below 300℃, which is larger and shows bigger fluctuation within the temperature range from 350℃ to 550℃. The worn surface shows desquamation, adhesive wear and oxidation wear.