目的 通过退火来提高等离子熔覆FeCoCrNiAl高熵合金涂层的耐磨性。方法 通过等离子熔覆技术在45号钢基体上制备了FeCoCrNiAl高熵合金涂层，并分别在500、800、1200 ℃温度下退火2 h。退火前后的涂层由XRD、能谱仪、扫描电镜、三维形貌仪、摩擦磨损试验机、硬度仪对其组织形貌及力学性能进行测试与表征。结果 退火前的FeCoCrNiAl熔覆涂层由BCC相和大量非稳态FCC相构成。经500 ℃退火后，涂层形成了单一BCC相;经800 ℃退火后，涂层中的BCC相开始转变并析出均匀分布的FCC相。以上两个涂层的硬度均处于较高水平，但受FCC相的影响，经400 ℃摩擦磨损30 min后，800 ℃退火后的涂层的耐磨性开始降低。而1200 ℃退火后，涂层中析出了大量棒状和不规则形状的富Fe-Cr相，导致其硬度和耐磨性显著降低，涂层的磨损更严重。结论 未退火的涂层和经500 ℃退火后的涂层的磨损机制主要为磨粒磨损，经800 ℃退火后的涂层属于磨粒磨损和粘着磨损机制，而1200 ℃退火后的涂层主要是疲劳磨损、磨粒磨损和粘着磨损。

This paper aims to improvethe abrasive resistance of a plasma cladded FeCoCrNiAl high entropy alloy coating by annealing. The FeCoCrNiAl high entropy alloy coatings were prepared on a 45# steel substrate by plasma cladding technology. The cladded coatings were followed by annealing for 2 hours at 500 ℃, 800 ℃, and 1200 ℃, respectively. The microstructures and mechanical properties of both unannealed and annealed coatings were characterized through XRD, EDS, SEM, 3D morphometry, friction and wear tester, and Vikers hardness tester. It is proposed that the cladded FeCoCrNiAl coating before annealing consists of the BCC phase and plenty of unstable FCC phase. The single BCC phase was formed in the coating after annealing at 500 ℃, however, the BCC phase began to transform and a uniformly distributed FCC phase was precipitated when the annealing temperature reaches 800 ℃. The coatings annealed from these two temperatures both have a high level of hardness. However, the wear performance of the coating annealed from800 ℃ after friction and wear at 400 ℃ for 30 min is relatively poor, which is mainly attributed to the precipitation of the FCC phase. Furthermore, plenty of clavate and irregularly shaped Fe-Cr rich phases precipitate in the FeCoCrNiAl coating after annealing from 1200 ℃, resulting in a remarkable reduction of the hardness and more serious of wear of the coating. Further study suggests that the wear mechanism of FeCoCrNiAl coatings before annealing and after annealing from 500 ℃ is abrasive wear, the one annealed from 800 ℃ belongs to abrasive wear and adhesive wear, and the one annealed from 1200 ℃ has a combined mechanism of fatigue wear, abrasive wear and adhesive wear.