挤压变形对Mg-2.5Nd-0.5Zn-0.5Zr合金微观组织和力学性能的影响  

Effect of extrusion on microstructure and mechanical properties of Mg-2.5Nd-0.5Zn-0.5Zr alloy

作　　者：马俊飞[1] 张文丛[1] 王松辉 杨建雷[1] 陈文振[1] 崔国荣[1] MA Jun-fei;ZHANG Wen-cong;WANG Song-hui;YANG Jian-lei;CHEN Wen-zhen;CUI Guo-rong(School of Materials Science and Engineering,Harbin Institute of Technology at Weihai,Weihai 264209,China)

机构地区：[1]哈尔滨工业大学(威海)材料科学与工程学院,山东威海264209

出　　处：《塑性工程学报》2022年第2期185-190,共6页Journal of Plasticity Engineering

基　　金：航天科学技术基金资助项目(JZJJX20190024);威海市科研创新基金资助项目(2019KYCXJJYB23);山东省重大创新工程(2019JZZY010364);国防基础科研计划(JCK2018603C017)。

摘　　要：采用扫描电镜、透射电镜、X射线衍射和拉伸试验等技术,研究了不同挤压比制备出的Mg-2.5Nd-0.5Zn-0.5Zr合金的微观组织和力学性能。结果表明,初始材料为近似等轴晶粒,平均晶粒尺寸约为23.8μm,沿晶界析出大量离异的共晶Mg;Nd相,在晶界处共晶相呈连续网状分布。挤压之后合金组织明显细化,E1(挤压比为7.65)和E2(挤压比为12.56)合金平均晶粒尺寸分别为8.1和6.3μm,力学性能显著提高,E1合金沿挤压方向的抗拉强度、屈服强度和伸长率分别为231 MPa、152 MPa和18.9%;E2合金沿挤压方向的抗拉强度、屈服强度和伸长率分别为257 MPa、213 MPa和22.4%。E2合金板材的各向异性指数与E1合金相比明显降低,结果表明增大挤压比可以有效缓解Mg-2.5Nd-0.5Zn-0.5Zr合金板材的各向异性。The microstructure and mechanical properties of Mg-2.5 Nd-0.5 Zn-0.5 Zr alloy prepared with different extrusion ratios were studied by means of scanning electron microscopy, transmission electron microscopy, X-ray diffraction and tensile test. The results show that the initial material is approximately equiaxed grain with average grain size of 23.8 μm. A large number of divorced eutectic Mg;Nd phases are precipitated along the grain boundary, and the eutectic phases present a continuous network distribution at the grain boundary. After extrusion, the microstructure is obviously refined, and the average grain sizes of E1(extrusion ratio of 7.65) and E2(extrusion ratio of 12.56) alloy are 8.1 and 6.3 μm, respectively.The mechanical properties are improved remarkably, and the tensile strength, yield strength and elongation of E1 alloy are 231 MPa, 152 MPa and 18.9%, respectively. The tensile strength, yield strength and elongation of E2 alloy are 257 MPa, 213 MPa and 22.4%, respectively. The anisotropy index of E2 alloy sheet is significantly lower than that of E1 alloy. The results show that the anisotropy of Mg-2.5 Nd-0.5 Zn-0.5 Zr alloy sheet can be effectively alleviated by increasing extrusion ratio.

关 键 词：Mg-2.5Nd-0.5Zn-0.5Zr合金 挤压 微观组织 力学性能 

分 类 号：TG306[金属学及工艺—金属压力加工]