金属热处理 ›› 2020, Vol. 45 ›› Issue (3): 68-72.DOI: 10.13251/j.issn.0254-6051.2020.03.014

• 材料研究 • 上一篇    下一篇

Al含量对含稀土AZ系镁合金组织及性能的影响

秦晨, 赵莉萍, 陈利超, 牛嘉兴, 陈盛, 姜亚君   

  1. 内蒙古科技大学 材料与冶金学院, 内蒙古 包头 014010
  • 收稿日期:2019-09-19 出版日期:2020-03-25 发布日期:2020-04-03
  • 通讯作者: 赵莉萍,教授,E-mail:zhaoliping5195@126.com
  • 作者简介:秦 晨(1994—),男,硕士研究生,主要研究方向为镁、铝合金和先进钢铁材料基础研究及组织性能控制,E-mail:542267214@qq.com。
  • 基金资助:

    内蒙古自治区研究生教育创新计划研究生科研创新项目(201/0404051809)

Effect of Al content on microstructure and properties of AZ series magnesium alloy containing rare earth

Qin Chen, Zhao Liping, Chen Lichao, Niu Jiaxing, Chen Sheng, Jiang Yajun   

  1. School of Materials and Metallurgy, Inner Mongolia University of Science and Technology, Baotou Inner Mongolia 014010, China
  • Received:2019-09-19 Online:2020-03-25 Published:2020-04-03

摘要:

以含稀土AZ系镁合金为基,制备了铝含量分别为5%、7%、9%的合金试样,并对其进行435 ℃×24 h固溶+200 ℃×24 h时效处理,对试样的铸态、固溶态和时效态的显微组织进行了观察,随后测定了试样时效后的力学性能以及耐蚀性能。结果表明,铸态镁合金组织主要为α-Mg+β-Mg17Al12+Al11(La,Ce)3和(La,Ce)Al4;随着Al含量的增加,β-Mg17Al12和稀土化合物相增多,晶粒细化。固溶处理后,组织中的β-Mg17Al12相会逐渐溶解,随着Al含量的增多,溶解将会不完全,未溶的强化相β-Mg17Al12和稀土化合物相弥散分布在晶界及其附近处。时效处理后,随着Al含量的增加,组织中继续析出的β-Mg17Al12相增多,稀土化合物相尺寸细化。随着Al元素的增多,试样的抗拉强度和硬度逐渐增大,塑韧性则愈来愈差,耐腐蚀性越来越好。

关键词: AZ系镁合金, Al含量, 显微组织, 力学性能, 耐腐蚀性

Abstract:

Taking the AZ series magnesium alloy containing rare earth as the base alloy, specimens with 5%, 7% and 9% Al were prepared, and solution treatment at 435 ℃ for 24 h+aging at 200 ℃ for 24 h was carried out. Then the microstructures of as-cast, solid solution treated and aged specimens were observed, the mechanical properties and corrosion resistance of the specimens after aging were measured. The results show that the as-cast microstructure of the specimens is mainly α-Mg+β-Mg17Al12+Al11 (La,Ce)3 and (La,Ce)Al4. With the increase of Al content, the β-Mg17Al12 phase and rare earth compounds increase, and the grain refinement is achieved. After solution treatment, the β-Mg17Al12 phase in the microstructure gradually dissolves, the dissolution becomes uncompleted with the increase of Al content, and the undissolved strengthening phase β-Mg17Al12 and the rare earth compound phase disperse in and near the grain boundary. After aging treatment and with the increase of Al content, β-Mg17Al12 phase continues to precipitate and increases in the microstructure, and the size of rare earth compound phase is refined. With the increase of Al element, the tensile strength and hardness of the specimen increase gradually, while the plasticity and toughness are getting worse, the corrosion resistance is becoming better.

Key words: AZ series magnesium alloy, aluminum content, microstructure, mechanical properties, corrosion resistance

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