Abstract A refractory high-entropy alloy (HEA) coating with a composition close to MoFeCrTiWAlNb3 was fabricated by laser cladding on M2 high-speed steel. The as-cladded coating is mainly constituted by body-centered-cubic (BCC) solid solution, MC carbide and C14-Laves phase, and exhibits typical lamellar eutectic. To explore its performance at elevated temperature, these samples were annealed at 950 °C for 6 h–10 h in addition to a 4 h annealing treatment in the temperature range of 750 °C–950 °C. The results show that when the coating is annealed at 750 °C, its microstructure remains basically unchanged, and the hardness can reach 635 HV0.2. However, the hardness drops sharply due to the dissolution of the eutectic Laves phase as the annealing temperature increases. Interestingly, after annealing at 950 °C for 6 h–10 h, the hardness rises as the number of precipitated Laves phase and σ phase increases. The hardness and volume loss of the coating annealed at 950 °C for 8 h are 639 HV0.2 and 0.74 mm3, respectively, indicating that the coating has excellent high temperature softening resistance.

中文翻译：

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激光熔覆难熔MoFeCrTiWAlNb3共晶高熵合金涂层的退火诱导组织和性能演变

摘要 通过激光熔覆在M2高速钢上制备了一种成分接近MoFeCrTiWAlNb3的难熔高熵合金(HEA)涂层。熔覆态涂层主要由体心立方(BCC)固溶体、MC碳化物和C14-Laves相构成，呈现典型的层状共晶。为了探索其在高温下的性能，除了在 750°C-950°C 的温度范围内进行 4 小时的退火处理外，这些样品还在 950°C 下退火 6 小时-10 小时。结果表明，涂​​层在750℃退火时，其显微组织基本保持不变，硬度可达635HV0.2。然而，随着退火温度的升高，由于共晶Laves相的溶解，硬度急剧下降。有趣的是，在 950 °C 下退火 6 h–10 h 后，硬度随着析出的 Laves 相和 σ 相的数量增加而增加。950 ℃退火8 h的涂层硬度和体积损失分别为639 HV0.2和0.74 mm3，表明涂层具有优异的耐高温软化性能。