激光熔覆CoCrFeNiSix高熵合金涂层的组织与性能

为了探究激光熔覆工艺对高熵合金组织和性能的影响，使用激光熔覆技术在Q235基材表面制备不同熔覆工艺下的高熵合金涂层. 利用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪等对高熵合金涂层进行显微组织形貌的观察及物相分析；利用显微硬度计、摩擦磨损试验机对涂层的硬度及耐磨性进行研究. 结果表明，宏观形貌上，扫描速度一定时，激光功率增大，涂层宽度增加，涂层表面更加平整； 激光功率一定时，扫描速度增加，熔覆层的宽度减小，相结构主要由体心立方(BCC)和面心立方(FCC)组成，扫描速度的增大或激光功率的降低，涂层中的晶粒变细小，且部分区域的胞状晶有向树枝晶生长的趋势，涂层硬度明显高于基材，最高可以达到553 HV，耐磨性要优于基体.

Alloy design strategies and future trends in high-entropy alloys

In order to investigate the effect of laser cladding process on the microstructure and properties of high entropy alloys, laser cladding technology is used to prepare high entropy alloy coatings on the surface of Q235 substrates under different cladding processes. The microstructure of the high-entropy alloy coating is observed and analyzed by optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometer, etc. The hardness and wear resistance of the coating are studied by micro hardness tester and friction wear tester. The results show that the coating width increases and the coating surface becomes flatter when the laser power increases for a certain scanning speed in macroscopic morphology. The width of the coating decreases when the scanning speed increases with a certain laser power. The phase structure is mainly composed of body-centered cubic (BCC) and face-centered cubic (FCC) structures. In microstructure, as the scanning speed increases or the laser power decreases, the grains in the coating become smaller and there is a tendency for the cellular crystals to grow into dendrite crystals in some areas. The hardness of the coating is significantly higher than that of the substrate, up to 553 HV; the wear resistance is better than that of the substrate.