Al_xCrFeNiMn高熵合金的组织和性能

Microstructure and properties of Al_xCrFeNiMn high entropy alloys

采用水冷铜坩埚悬浮熔炼与铜模吸铸相结合的方法制备了直径为3mm的AlxCrFeNiMn(x=0、0.25、0.5、0.75)系高熵合金,通过X射线衍射、光学显微镜、扫描电镜、室温压缩试验、硬度测试等探索了不同铝含量、热处理温度和时间对AlxCrFeNiMn系高熵合金微观组织及力学性能的影响。结果表明,铸态AlxCrFeNiMn(x=0、0.25、0.5、0.75)系合金的塑性变形基本相近,保持在34%左右,且铸态Al0.75CrFeNiMn高熵合金的显微硬度、规定塑性延伸强度与抗压强度分别为524.15HV0.3、765.86MPa与3236.69MPa;不同温度和时间的热处理结果表明:Al0.5CrFeNiMn具有更为细小且分布均匀的等轴晶,获得硬度最大值729.37HV0.3,并保持较大的塑性变形(30.33%),具有优良的力学性能。

Five-element high entropy alloys AlxCrFeNiMn(x=0,0.25,0.5,0.75)with diameter of 3 mm were prepared by a combined method of water cold copper crucible levitation melting and copper mould suction casting.The effects of different Al content,heat treatment temperature and time on the microstructure and mechanical properties of AlxCrFeNiMn series high-entropy alloys were investigated by X-ray diffraction,optical microscopy,scanning electron microscopy,room temperature compression and hardness test.The results show that plastic deformation of as-cast AlxCrFeNiMn(x=0,0.25,0.5,0.75)alloys is almost the same,which remains at about 34%;and the microhardness,specified plastic elongation strength and compressive strength of as-cast Al0.75CrFeNiMn high-entropy alloy are 524.15 HV0.3,765.86 MPa and 3236.69 MPa,respectively.The results of heat treatment at different temperatures and time show that the Al0.5CrFeNiMn alloy after heat treatment has a microstructure of finer equiaxed grains with uniform distribution,reaches the maximum hardness value of 729.37 HV0.3,maintains a large plastic deformation(30.33%),and has excellent mechanical properties.