采用激光熔覆技术在H11钢表面制备厚度为150 μm的Al2CoCrCuFeNi高熵合金涂层, 研究了涂层的组织结构、显微硬度和耐磨性能。实验得到优化的多道搭接工艺参数为电流270 A、扫描速度3 mm/s、离焦量－14 mm、搭接率40%。在涂层中形成以微观组织为枝晶和枝晶间组织的简单固溶体。熔覆层上部组织由等轴晶粒组成, 而下部组织由柱状晶粒组成, 并且基体/涂层之间形成冶金结合。涂层的平均显微硬度比基体250 HV的硬度增加了70%; 涂层试样的磨损率只有基体的30%, 相比H11钢基体, 高熵合金熔覆层显微硬度和耐磨性都大大提高。

Preparation of Al2CoCrCuFeNi high-entropy alloy coating with thickness of 150μm on the surface of H11 steel by laser cladding technology was studied. The optimized multi-pass lap process parameters were obtained: the current was 270A; the scanning speed was 3mm·s-1; the defocus was fixed at-14mm; 40% track overlapping condition was used. The microstructure, microhardness and wear resistance of the coating were investigated. The results show that Simple solid solution phases were formed in the coating layer with a typical microstructure at the top of the cladding zone consists of equiaxed grains while that at the bottom consists of columnar grains, And metallurgical bonding is formed between the substrate/coating. The average microhardness of the coating layer shows 70% enhancement compared with that (HV 250) of the H11 substrate; The wear rate of the coated sample is 30% that of the H11 substrate. The coating layer exhibits great enhancement in microhardness and wear resistance compared with the H11 substrate.