稀土微合金化对Mg-9Li-1Zn合金组织性能的影响  

Microstructure and Mechanical Properties of Mg-9Li-1Zn Alloy with RE Elements Multi-micro Alloying

作　　者：王红亮 谢圣中[1] 林建国 Wang Hongliang;Xie Shengzhong;Lin Jianguo(Hunan Nonferrous Metals Vocational and Technical College;School of Materials Science and Engineering,Xiangtan University)

机构地区：[1]湖南有色金属职业技术学院,湖南株洲412000 [2]湘潭大学材料科学与工程学院,湖南株洲412000

出　　处：《特种铸造及有色合金》2021年第3期344-348,共5页Special Casting & Nonferrous Alloys

基　　金：湖南省教育厅科学研究资助项目(19C1376);湖南省自然科学基金资助项目(2018JJ5047)。

摘　　要：通过复合添加0.2%的Y+0.1%的Nd+0.05%的Gd(质量分数,下同)制备了轻质高强Mg-9Li-1Zn-RE合金(LZ91-RE),随后对其进行锻造和冷轧。采用OM、SEM、EDS、XRD、TEM对锻造态和冷轧态LZ91合金和LZ91-RE合金进行组织及物相分析,同时利用拉伸试验机进行力学性能测试。结果表明,LZ91合金组织由α-Mg和β-Li两相组成,添加多元稀土元素后LZ91合金中α相体积分数减少了26.5%,晶粒得到显著细化,同时原位析出了富Y、富Nd、Mg_(12)Nd及Mg_(3)RE稀土强化相,但存在局部偏聚现象;LZ91-RE合金经过大应变冷轧变形,稀土强化相被破碎细化且分布更加均匀。此外,与LZ91合金相比,锻造态的LZ91-RE合金抗拉强度比LZ91合金提高了13.9%。冷轧态的LZ91-RE合金的抗拉强度比LZ91合金提高了19%,而伸长率只下降了4.4%。The multiple trace rare earth elements RE(0.2%Y+0.1%Nd+0.05%Gd)(mass percentage)were added to prepare light and high-strength Mg-9Li-1Zn-RE alloy(LZ91-RE),which was subsequently forged and cold rolled.The microstructure and phase of the as-forged and as-rolled LZ91 alloy and LZ91-RE alloy were analyzed by means of OM,SEM,EDS,XRD,TEM.Meanwhile,the mechanical properties of the alloy prepared were tested by the tensile testing machine.The results reveal that the microstructure of LZ91 alloy consists of two phases ofα-Mg andβ-Li.After the addition of multiple rare earth elements,the volume fraction ofαphase in LZ91 alloy is reduced by 26.5%,and the grains are significantly refined.Y-rich,Nd-rich,Mg_(12)Nd and Mg_(3)RE rare earth strengthening phases are in-situ precipitated,however there exists a local segregation.After deformation of the LZ91-RE alloy by cold rolling with large strain,the rare earth strengthening phases in the alloy are broken and refined with more uniform distribution.In addition,compared with that of the LZ91 alloy,the tensile strength of the as-forged LZ91-RE alloy is increased by 13.9%.The tensile strength of the cold-rolled LZ91-RE alloy is increased by 19%,while the elongation is only reduced by 4.44%.

关 键 词：Mg-9Li-1Zn合金 稀土元素 显微组织 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]