机械合金化联合真空热压烧结工艺制备CoCrFeNi高熵合金的力学性能和耐腐蚀性能

采用机械合金化和真空热压烧结工艺制备了CoCrFeNi高熵合金。采用X射线衍射仪、扫描电子显微镜、电感耦合等离子体发射光谱和光学显微镜对产物的相结构和微观结构进行了表征，并采用万能试验机、维氏硬度计和电化学工作站对其力学性能和耐腐蚀性能进行了研究。结果表明：与电化学还原联合热压烧结工艺以及电弧熔炼法制备的CoCrFeNi高熵合金性能相比，机械合金化联合真空热压烧结工艺制备的CoCrFeNi高熵合金具有良好的抗拉伸强度和断裂伸长率，其合金硬度是电弧熔炼法制备合金的2倍，在0.5 mol/L H₂SO₄、1 mol/L KOH和3.5%（质量分数）NaCl水溶液中，该合金具有与304不锈钢及电化学还原联合热压烧结工艺或电弧熔炼法制备的合金相当的耐腐蚀性能。

Mechanical Properties and Corrosion Resistance Behavior of CoCrFeNi High-Entropy Alloy Prepared by Mechanical Alloying Coupled with Vacuum Hot Pressing Sintering

CoCrFeNi high-entropy alloy (HEA) was fabricated by mechanical alloying (MA) and vacuum hot pressing sintering (VHPS). The phase and microstructure of alloys were characterized by X-ray diffraction, scanning electron microscope, inductively coupled plasma-optical emission spectrometer, and optical microscope. The mechanical properties and corrosion resistance were investigated by universal tensile machine, Vickers hardness tester, and electrochemical workstation. Results show that CoCrFeNi HEA prepared by MA-VHPS exhibits excellent ultimate tensile strength and elongation, compared with those prepared by the arc-melting method and the combined method of the electrochemical reduction (FFC) with VHPS. The hardness of CoCrFeNi HEA prepared by MA-VHPS is twice larger than that prepared by arc-melting. The CoCrFeNi HEA prepared by MA-VHPS displays corrosion resistance in 0.5 mol/L H₂SO₄, 1 mol/L KOH, and 3.5wt% NaCl solutions, comparable to that of the 304 stainless steel and CoCrFeNi HEAs prepared by FFC-VHPS or arc-melting.