热处理对FeCrMnNiAl_(x)高熵合金组织及拉伸性能的影响

Effects of Heat Treatment on Microstructure and Tensile Properties of FeCrMnNiAl_(x)High-entropy Alloys

采用真空感应熔炼技术制备了FeCrMnNiAl_(x)(x=0,0.1)高熵合金,并对高熵合金进行热处理,采用X射线衍射仪、扫描电镜和万能拉伸试验机分别对合金进行物相组成、组织形貌以及拉伸性能的测试与表征。结果表明,FeCrMnNiAl_(x)(x=0,0.1)合金均为FCC+BCC的双相固溶体合金,Al原子以间隙原子的形式固溶到基体合金中;添加Al元素后,合金的枝晶状组织转变为孤岛状组织,并且在该处形成了微米级针状的第二相,经热处理后,第二相由微米级针状转变为纳米级颗粒状;Al的添加有效提升了高熵合金的强度,FeCrMnNiAl_(0.1)高熵合金经800℃热处理后,抗拉强度和屈服强度比铸态的分别提高31.7%和17.5%,合金仍具有约21.1%的伸长率,适当的热处理能够提高高熵合金综合力学性能。

The high-entropy alloy FeCrMnNiAl_(x)(x=0,0.1)was prepared by vacuum induction melting technology and then was heat treated.The phase composition,microstructure and tensile properties of the alloy were measured and characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and universal tensile testing machine,respectively.The results show that FeCrMnNiAl_(x)(x=0,0.1)alloys are all FCC+BCC two-phase solid solution alloys,and Al atoms are dissolved into the matrix alloy in the form of interstitial atoms.When Al is added,the dendritic structure of the alloy is transformed into an island structure,and the micron-size needle-like second phase is formed there.After heat treatment,the second phase is transformed from micron-size needle like to nanometer granular.The addition of Al effectively enhances the strength of the high-entropy alloy.After heat treatment at 800℃,the tensile strength and yield strength of FeCrMnNiAl_(0.1) high-entropy alloy are increased by 31.7%and 17.5%,respectively than that of as cast state,and the alloy still has about 21.1%elongation.Proper heat treatment can improve the comprehensive mechanical properties of high-entropy alloy.