Mg-Gd-Y-Nd-Zr合金的微观组织和力学性能

Microstructures and Mechanical Properties of Mg-Gd-Y-Nd-Zr Alloy

利用光学金相显微镜、扫描电镜、X射线衍射和透射电镜等研究了名义成分为Mg-8.0Gd-2.5Y-0.5Nd-2.0Zr的合金的显微组织,测试了合金的力学性能。研究表明,Mg-8.0%Gd-2.5%Y-0.5%Nd-2.0%Zr合金的铸态组织主要由α-Mg基体和主要沿晶界分布的第二相Mg5Gd和Mg24Y5组成,固溶处理后,Mg5Gd和Mg24Y5相基本消失,再经时效处理后,合金达到较好的力学性能,其室温、250℃和300℃的抗拉强度分别为312.04 MPa,271.99 MPa和199.81 MPa,其对应的延伸率分别为:3.4%,7.0%和12.7%。

The microstructure of magnesium alloy whose nominal composition is Mg-8.0Gd-2.5Y-0.5Nd-2.0Zr was investigated by means of optical microscopy, scanning electron microscopy, X-ray texture analysis and transmission electron microscopy, and the mechanical properties were obtained. The results show that the as-cast microstructures of Mg-8.0%Gd-2.5%Y-0.5%Nd-2.0%Zr alloy consists of α-Mg matrix and lamellar second-phase (Mg5Gd and Mg24Y5 phase) which distributes around α-Mg matrix. The Mg5Gd and Mg24Y5 phase basically disappeared after solution treatment. Then by aging treatment, alloys reach a good mechanical property. The mechanical properties of studied alloy at room temperature, 250?C and 300?C reach 312.04 MPa, 271.99 MPa and 199.81 MPa;the corresponding elongations are 3.4%, 7.0% and 12.7%.