粉末冶金法制备CrFeNiCuMoCo高熵合金的组织与性能

利用粉末冶金法制备CrFeNiCuMoCo高熵合金,用带有能谱的扫描电子显微镜(SEM/EDS)、X射线衍射仪、显微/维氏硬度计、电化学工作站、材料试验机等对CrFeNiCuMoCo高熵合金组织结构进行分析并测试其硬度、耐蚀性和压缩性能.结果表明:CrFeNiCuMoCo高熵合金组织形貌简单；物相主要由FCC和BCC两相组成,Mo元素和Cu元素在合金中存在偏析现象；合金的耐蚀性能优异,与304不锈钢相比,自腐蚀电流密度减小1个数量级;组元间原子半径的差异导致较大的晶格畸变,阻碍位错的运动,使得固溶强化效应增强；Mo元素起到细化晶粒作用,使该合金具有较高的硬度和抗压强度,合金硬度为485 HV,抗压强度约为1 385MPa;断裂类型为脆性解理断裂.

Microstructure and properties of CrFeNiCuMoCo high-entropy alloy prepared by powder metallurgy

The CrFeNiCuMoCo high-entropy alloy was prepared by powder metallurgy method.Using scanning electron microscopy with spectroscopy(SEM/EDS),X-ray diffraction,micro/vickers hardness tester,electrochemical workstation and material testing machine analyze the microstructure,phase composition,hardness,corrosion resistance,compression properties of the CrFeNiCuMoCo high-entropy alloy,respectively.The results show that the morphology of the CrFeNiCuMoCo high-entropy alloy is simple,the phase mainly composes of FCC and BCC;Mo and Cu are segregated in the alloy;the alloy shows excellent corrosion resistance,the corrosion current density decreases by an order of magnitude compared with 304 stainless steel;the difference in atom radius among components leads to larger lattice distortion,blocks the dislocation motion and enhances the solid solution strengthening effect.Since Mo elements can refine grains,the CrFeNiCuMoCo high-entropy alloy has high hardness of 485 HV and compressive strength of 1 385 MPa.The type of alloy fracture is brittle cleavage fracture.