目的 研究 Al3CoCrCu1/2FeMoNiTi 高熵合金涂层的退火时效硬化及其强化机理。 方法 使用激光熔覆设备，在 40Cr 钢上制备了 Al3CoCrCu1/2FeMoNiTi 高熵合金涂层，对涂层进行了退火处理。使用X 射线衍射仪、扫描电子显微镜和显微硬度计对涂层进行了分析。结果 涂覆态涂层为 BCC 单相结构，经 300 ℃和 500 ℃退火，涂层仍然为 BCC 单相；700 ℃退火后，涂层析出了 NiTi 金属间化合物相；900 ℃退火后，涂层由 FCC 相及 NiTi 金属间化合物组成。涂覆态和经 300~700 ℃退火的涂层为胞粒状，经900 ℃退火后，涂层为板条状。经 300 ℃退火，涂层硬度下降， 但超过 300 ℃退火，硬度比涂覆态的高。700 ℃退火合金硬度达到最大值 924HV。退火温度升到 900 ℃后，硬度比 700 ℃退火的低。 NiTi 析出相促进了硬度提高，位错强化机制能较好解释该高熵合金的固溶强化现象。结论 Al3CoCrCu1/2FeMoNiTi合金涂层具有明显的时效硬化效应， 700 ℃退火可获得最佳的时效硬化效果。

Objective To investigate the annealing age hardening of Al3CoCrCu1/2FeMoNiTi high-entropy alloy coating and strengthening mechanism. Methods Al3CoCrCu1/2FeMoNiTi high-entropy alloy coating was deposited on 40Cr steel with laser cladding equipment, and then was annealed. X-ray diffractometer, scanning electron microscope and microhardness tester were employed to analyze microstructure and hardness. Results The original coating was of BCC single-phase structure. After annealing at 300 ℃ and 500 ℃, the coating was still of BCC structure. The coating annealed at 700 ℃ precipitated NiTi intermetallic compound phase. When the annealing temperature was 900 ℃, the coating was composed of FCC phase and NiTi. The coating SEM morphology that was annealed at 0~700 ℃ was granular. After annealing at 900 ℃, the morphology was like lath. The coating annealed at 300 ℃ had a lower hardness than that of non-annealed. The hardness increased when the annealing temperature was more than 300 ℃. It reached the highest about 924HV at 700 ℃. It then became lower at 900 ℃. NiTi phase precipitating improved the alloy hardness. Solid solution strengthening of high-entropy alloys could be explained by dislocation strengthening mechanism. Conclusion Al3CoCrCu1/2FeMoNiTi high-entropy alloy coating obviously shows age hardening effect. The alloy coating has the best hardness after annealing at 700 ℃.