Gd元素添加对铸态AS41合金组织和性能的影响

Effect of Gd Element Addition on Microstructure and Mechanical Properties of As-Cast AS41 Alloy

为研究Gd元素对Mg-4Al-1Si合金组织与拉伸性能的影响,制备了Mg-4Al-1Si-x Gd(x=0,1,2)合金。利用OM、SEM、XRD、万能电子试验机等分析了合金的显微组织、相组成,测试了拉伸性能。结果表明:第二相尺寸和分布在加入Gd元素后得到显著改善,Gd与合金中Si结合形成新的Si3Gd5相,Mg2Si相由大尺寸鱼骨状变成短小杆状,少量Mg17Al12以颗粒状均匀分布。与Mg-4Al-1Si合金相比,添加Gd元素有效提高了合金的抗拉强度和伸长率。Gd含量为1wt.%时,合金的综合力学性能最佳,其中抗拉强度达到119.7MPa,屈服强度为62.3 MPa,伸长率达到5.5%。

In the experiment, Mg-4Al-1Si-xGd(x=0, 1, 2) alloys were fabricated to study the effect of Gd element on the microstructure and tensile properties of Mg-4 Al-1 Si alloy. By means of OM, SEM, XRD and universal the electronic testing machine, the microstructure and phase constituents were analyzed, the tensile properties were tested. The results show that the addition of Gd element improves the size and distribution of the second phase;Gd combines with Si in the alloy to form a new Si3 Gd5 phase;the fishbone-like large-sized Mg2 Si phase becomes short rods, and a small amount of Mg17 Al12 phase uniformly distribute in the granular form. Compared with the Mg-4 Al-1 Si alloy, the addition of Gd element improves the tensile strength and elongation of the alloy. When the Gd content is 1 wt.%, the alloy has the good combination of the mechanical properties,, among which the tensile and yield strengths as well as the elongation reach 119.7 MPa, 62.3 MPa and 5.5%, respectively.