东北大学学报:自然科学版 ›› 2015, Vol. 36 ›› Issue (10): 1422-1426.DOI: 10.3969/j.issn.1005-3026.2015.10.012

• 材料与冶金 • 上一篇    下一篇

稀土Y对挤压态Mg-5Li合金组织及性能的影响

祖国胤, 杜鹏, 宋洪全, 孙世亮   

  1. (东北大学 材料与冶金学院, 辽宁 沈阳110819)
  • 收稿日期:2014-09-09 修回日期:2014-09-09 出版日期:2015-10-15 发布日期:2015-09-29
  • 通讯作者: 祖国胤
  • 作者简介:祖国胤(1977-),男,黑龙江齐齐哈尔人,东北大学教授,博士生导师.
  • 基金资助:
    国家自然科学基金资助项目(U1332110).

Effects of Y on Microstructure and Properties of As-Extruded Mg-5Li Alloys

ZU Guo-yin, DU Peng, SONG Hong-quan, SUN Shi-liang   

  1. School of Materials & Metallurgy, Northeastern University, Shenyang 110819, China.
  • Received:2014-09-09 Revised:2014-09-09 Online:2015-10-15 Published:2015-09-29
  • Contact: ZU Guo-yin
  • About author:-
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摘要: 采用表面覆盖剂及氩气保护的熔炼方法制备了Mg-5Li-xY(x=0, 1, 2, 3, 4)合金,研究了稀土元素Y对挤压态Mg-5Li合金的显微组织及力学性能的影响.研究结果表明,Mg-5Li合金中的Y元素主要是以稀土化合物Mg24Y5的形式存在于合金中;挤压变形后,合金发生了明显的动态再结晶,出现了大量的等轴晶,弥散分布的Mg24Y5相阻碍了动态再结晶过程中的晶粒长大,晶粒明显细化.挤压态Mg-5Li-3Y合金获得了优异的力学性能,其抗拉强度和断裂伸长率分别达到了231.63MPa和9.35%,合金断裂方式主要为韧性断裂.

关键词: 镁锂合金, 稀土Y, 挤压变形, 显微组织, 力学性能

Abstract: With the protection of surface covering agents and argon protection, the Mg-5Li-x Y(x=0, 1, 2, 3, 4) alloys were prepared by conventional casting methods. The effects of rare earth on microstructure and mechanical properties of the as-extruded alloys were investigated. The results showed that the RE compound Mg24Y5 generated after adding Y into the Mg-5Li alloy. The dynamic recrystallization arose during the hot extrusion process, leading to a large number of equiaxed grains appeared. The dispersive distribution of Mg24Y5 phase hindered the growth of the grains during the dynamic recrystallization, which led to the grain refinement. The as-extruded Mg-5Li-3Y alloy achieved the best mechanical property: the tensile strength and elongation reached up to 231.63MPa and 9.35%, respectively. The fracture mode of the alloy is mainly ductile fracture.

Key words: Mg-Li alloy, rare earth Y, extrusion, microstructure, mechanical property

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