稀土元素Y对Mg-Nd-Zn-Zr合金组织和高温力学性能的影响  

Effect of Y on Microstructure and High Temperature Mechanical Properties of Mg-Nd-Zn-Zr Alloys

作　　者：刘娟[1] 夏长清[1] 张志高[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《矿冶工程》2008年第4期94-97,共4页Mining and Metallurgical Engineering

摘　　要：制备了Mg-5.0Y-3.0Nd-0.5Zn-0.5Zr和Mg-3.0Nd-0.5Zn-0.5Zr2种合金,研究了Y元素和Nd元素对合金组织和高温力学性能的影响。通过XRD分析了合金的物相组成进行了定性分析。稀土元素Nd在Mg-Nd-Zn-Zr合金中以Mg12Nd相存在于铸态组织晶界,Nd、Y在Mg-Y-Nd-Zn-Zr中以Mg41Nd5和Mg24Y5相存在于铸态组织晶界。这些相均具有很好的耐热性,是主要的强化相。研究结果表明,Y对合金铸态组织有明显细化作用。合金挤压轧制后经过T6处理后进行高温拉伸,与Mg-3.0Nd-0.5Zn-0.5Zr相比,加Y的Mg-5.0Y-3.0Nd-0.5Zn-0.5Zr合金的抗拉强度和延伸率明显提高。300℃的抗拉强度达到了168.5MPa,延伸率为28.8%。Two alloys of Mg-5.0Y-3.0Nd-0.5Zn-0.5Zr and Mg-3.0Nd-0.5Zn-0.5Zr were prepared. The effect of elements of Y and Nd on microstructure and high temperature mechanical properties of the alloys was researched. The alloy phases were analyzed by X-ray diffraction （XRD）. The element Nd exists as Mg12Nd in the grain boundaries with cast structure in Mg-Nd-Zn-Zr alloys, while Nd and Y as Mg41Nd5 and Mg24Y5 respectively in the grain boundaries with cast structure in the alloys. These phases are the main strengthening phase because of their nice thermal stability. The research results showed that Y was able to greatly refine the alloy cast structure. After extrusion-rolling, T6 treatment and high temperature drawing of the alloys, the tensile strength and specific elongation of Mg-5.0Y-3.0Nd-0.5Zn-0.5Zr containing element Y was obvious better than that of Mg-3.0Nd-0.5Zn-0.5Zr. At 300℃, the tensile strength and elongation of the former were 168.5 MPa and 28.8% respectively.

关 键 词：镁合金 显微组织 稀土元素 高温力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]