Gd对Mg-6Al-1Nd合金高温蠕变行为与力学性能的影响  

Effect of Gd on high temperature creep behavior and mechanical properties of Mg-6Al-1Nd alloy

作　　者：王武孝[1] 王娜[1] 秦子禾 刘健[1] 秦少勇 WANG Wu-xiao;WANG Na;QIN Zi-he;LIU Jian;QIN Shao-yong(School of Material Science and Engineering,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048

出　　处：《材料热处理学报》2020年第9期67-75,共9页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51771146);陕西省自然科学基础研究计划项目(2019JM-180)。

摘　　要：采用光学显微镜(OM),X射线衍射分析(XRD),扫描电镜(SEM)和力学性能测试等方法研究了Gd添加对Mg-6Al-1Nd合金显微组织、高温压缩蠕变行为(150℃、90 MPa)以及高温拉伸力学性能(150℃)的影响。结果表明:在Mg-6Al-1Nd合金中加入稀土元素Gd后,Mg-6Al-1Nd-xGd合金的物相组成为α-Mg相、β-Mg17Al12相以及金属间化合物Al2Nd和Al2Gd相,组织中的β-Mg17Al12相由连续网状分布逐渐变得不连续;当Gd添加量为1.5%时,合金的蠕变量及稳态蠕变速率分别为1.95%和1.946×10^-8,较Mg-6Al-1Nd合金的3.25%和3.209×10^-8分别降低了40%和39.3%,合金的高温压缩蠕变性能大幅提高;当Gd添加量为0.5%时,合金在室温及高温下具有最大的抗拉强度,分别为183.13 MPa和181.45 MPa,较Mg-6Al-1Nd合金的130.54 MPa和114.11 MPa分别提高了40.3%和59%。The effects of Gd addition on microstructure,high-temperature compressive creep behavior(150℃,90 MPa),and high-temperature tensile mechanical properties(150℃)of Mg-6 Al-1 Nd alloy were studied by means of optical microscope(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),and mechanical property test.The results show that after adding rare earth element Gd to the Mg-6 Al-1 Nd alloy,the phase composition of the Mg-6 Al-1 Nd-xGd alloy is composed ofα-Mg phase,β-Mg17Al12 phase and metal compounds Al2Nd and Al2Gd phases,and theβ-Mg17Al12 phase gradually becomes discontinuous from continuous network distribution.When the addition of Gd is 1.5%,the creep and the steady-state creep rate of the alloy are 1.95%and 1.946×10^-8,respectively,which are 40%and 39.3%lower than that of the Mg-6 Al-1 Nd alloy,respectively,and the high-temperature compression creep performance of the alloy is greatly improved.When the addition of Gd is 0.5%,the alloy has the largest tensile strength at room temperature and high temperature,which is 183.13 MPa and 181.45 MPa,respectively,which is 40.3%and 59%higher than that of the Mg-6 Al-1 Nd alloy,respectively.

关 键 词：Mg-6Al-1Nd合金 GD 金属间化合物 高温蠕变 抗拉强度 

分 类 号：TG146.2[一般工业技术—材料科学与工程]