Nd和Ce对AZ91镁合金组织和力学性能的影响  

Effects of Nd and Ce on Microstructure and Mechanical Properties of AZ91 Magnesium Alloy

作　　者：赵源华[1] 陈云贵[1] 唐永柏[1] 肖素芬[1] 牛高[1] 魏尚海[1] 章晓萍[1] 

机构地区：[1]四川大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2009年第1期69-72,共4页Special Casting & Nonferrous Alloys

基　　金：四川省科技厅重点攻关项目(04GG1589)

摘　　要：利用SEM和XRD等方法研究了总含量为2.5%的单独或复合加入Nd和Ce的AZ91镁合金的铸态显微组织和相组成,并测试和分析了合金的室温力学性能。结果表明,单独加Nd和单独加Ce的AZ91合金中形成的稀土相分别是块状的Al2Nd相和针状的Al11Ce3相,二者混合加入时两种稀土相同时出现,两种稀土相的相对含量与两种RE元素的相对含量相关。当混合加入Nd和Ce时,合金的Al2Nd相中的部分Nd和Al11Ce3相中的部分Ce分别被Ce和Nd置换;Nd和Ce的加入可以明显改善AZ91合金的力学性能,其原因与稀土相消耗基体中部分Al、RE的晶粒细化、弥散强化等有关。其中AZ91+1.0Nd+1.5Ce合金的力学性能最好,其铸态合金的抗拉强度和伸长率分别达到240MPa和11%。As-cast microstructure and phase constituent of AZ91 magnesium alloy containing 2.5% RE (RE presents Nd or Ce only or mixed Nd and Ce ) were observed by means of SEM (scanning electron microscope) and XRD (X-ray diffraction), and ambient mechanical properties of the alloy were measured. The results indicate that bulk Al2Nd phase and acicular Al11Ce3 phase can be created in the AZ91 magnesium alloy with Nd addition only and one with Ce addition only, respectively. Meanwhile, both the bulk Al2Nd phase and acicular Al11Ce3 phase can be generated in the AZ91 alloy with mixed addition of Nd and Ce, in which relative content is positively related to the relative concentration of Nd and Ce, in which a part of Nd atom in the Al2Nd phase is substituted by Ce atom and a part of Ce atom in the Al11Ce3 phase is substituted by Nd. Mechanical properties of AZ91 magnesium alloy can be acceptably improved with addition of Nd and Ce, which is attributed to the depletion of Al in matrix by RE phase and the refinement of grain as well as dispersion strengthening, and the tensile strength and elongation of as-cast alloy are 240MPa and 11%, respectively, with 1.0% Nd and 1%Ce mixed addition, exhibiting desirable mechanical properties.

关 键 词：AZ91镁合金 CE ND 组织结构 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]