CoCrFeNiCuTix高熵合金的微观组织与耐腐蚀性能研究

采用真空热压烧结法制备了CoCrFeNiCuTi_x (x为摩尔比, x=0.25, 0.50, 0.75, 1.00)六元高熵合金, 研究了Ti含量对该高熵合金微观组织和耐腐蚀性的影响。利用金相显微镜、X射线衍射仪、扫描电子显微镜、HVS-1000B型数显显微硬度计和电化学工作站等设备测试和分析了CoCrFeNiCuTi_x高熵合金的组织结构和耐腐蚀性能。结果表明: 不同Ti含量(摩尔分数)的CoCrFeNiCuTi_x高熵合金, 物相都为面心立方结构, 组织主要为树枝晶; 随着Ti摩尔分数的增加, 高熵合金树枝晶组织减少, 硬度先增加后减小, x=0.50时, 合金的硬度值最大, 为HV 755;CoCrFeNiCuTi_x高熵合金的自腐蚀电位都正于45#钢, 耐腐蚀性先增强后减弱, x=0.50时, 其耐腐蚀性最优。

Study on microstructure and corrosion resistance of CoCrFeNiCuTi_x high-entropy alloy

The CoCrFeNiCuTix(x = 0.25, 0.50, 0.75, 1.00 by molar) high-entropy alloys(HEAs) were prepared by vacuum hot-pressing sintering in this paper. The effects of Ti contents on the microstructure and corrosion resistance of the CoCrFeNiCuTix HEAs were investigated and analyzed by optical microscope(OM), X-ray diffractometer(XRD), scanning electron microscope(SEM), HVS-1000 B digital microhardness tester, and electrochemical workstation. The results show that the CoCrFeNiCuTix HEAs with different Ti contents by molar have the face-centeredcubic phase structure with the dendritic crystal microstructures. With the increase of Ti content, the dendritic structure declines in numbers, and the hardness of CoCrFeNiCuTix HEAs increases first and then decreases;the microhardness of the prepared HEAs reaches the maximum up to HV 755 at x = 0.5. The self-corrosion potential of the prepared HEAs is positive to that of 45# steel;with the increase of Ti content by molar, the self-corrosion potential of the prepared HEAs increases first and then decrease, and the best corrosion resistance is obtained at x = 0.5.