Sm对AZ80镁合金组织和力学性能的影响

Influence of Sm addition on microstructure and mechanical properties of AZ80 magnesium alloys

采用真空感应熔炼法制备了AZ80-xSm合金(x=0、0.6、1.0、1.5),研究了不同含量的Sm对AZ80镁合金合金组织和力学性能的影响。通过金相显微镜、扫描电镜、透射电镜、EDS、XRD观察和分析了合金的微观形貌和组织结构,测量了合金抗拉强度和伸长率。结果表明,合金中添加稀土元素Sm后晶粒明显细化;生成颗粒状析出相(Al3Sm),减少合金中β相(Mg l7Al l2)的数量,并使连续网状分布的β相断续,Al3Sm相对合金的强化效果明显优于β相,使AZ80镁合金的力学性能得到提高,其中AZ80-1.0Sm合金抗拉强度达到213 MPa,比原始合金提高了21.7%。

AZ80-xSm （x = 0, 0.6, 1.0, 1.5） series alloys were prepared by medium-frequency induction melting method. The influence of Sm addition on microstructure and properties of AZS0 alloys was investigated. The phases and microstrueture of the alloys were researched by optical microscope, SEM, TEM, EDS analysis and XRD. The mechanical properties such as tensile strength and elongation of the alloys were measured. The results show that the addition of Sm can obviously refine the mierostructure of the as-cast AZ80 alloy. A new granular precipitated phase （A13Sm） is found in the AZ80-xSm alloys, which reduces the amount of β phase and transforms the continuous net β phase into discontinuous distribution. AI3Sm phase is more effective than β phase for preeipitation strengthening of the AZ80 alloy, and therefore the mechanical properties of the AZ80 alloy are improved. The tensile strength of AZ80-1.0Sin is 213 MPa, which increases by 21.7% comparing with that of the parent alloy.