金属热处理 ›› 2020, Vol. 45 ›› Issue (6): 129-135.DOI: 10.13251/j.issn.0254-6051.2020.06.028

• 组织与性能 • 上一篇    下一篇

Mg-3Al-1Si-xSr合金的组织和蠕变性能

陈鑫浩, 刘馨忆, 李永祥, 王旺兵, 张智超, 王旭   

  1. 辽宁石油化工大学 机械工程学院, 辽宁 抚顺 113001
  • 收稿日期:2019-12-06 出版日期:2020-06-25 发布日期:2020-09-02
  • 通讯作者: 王 旭,副教授,E-mail:wangxu@lnpu.edu.cn
  • 作者简介:陈鑫浩(1994—),男,硕士研究生,主要研究方向为材料的组织与性能,E-mail:1974908831@qq.com。
  • 基金资助:
    国家自然科学基金(51574147, 51790481)

Microstructure and creep properties of Mg-3Al-1Si-xSr alloy

Chen Xinhao, Liu Xinyi, Li Yongxiang, Wang Wangbing, Zhang Zhichao, Wang Xu   

  1. School of Mechanical Engineering, Liaoning Shihua University, Fushun Liaoning 113001, China
  • Received:2019-12-06 Online:2020-06-25 Published:2020-09-02

摘要: 通过Sr微合金化和热处理工艺(固溶和时效)来调整Mg-3Al-1Si合金的显微组织,从而提高试验合金的蠕变性能。结果表明:Sr元素和固溶时效处理对Mg-3Al-1Si合金的铸态组织均有很强的细化作用,Sr含量为0.4wt%,时效时间为24 h时,细化效果达到最佳;随Sr含量增加及时效时间延长,Mg-3Al-1Si合金的蠕变寿命提高,但时效36 h时出现过时效,蠕变寿命降低。Mg-3Al-1Si-0.4Sr合金经420 ℃×10 h固溶+180 ℃×24 h时效处理后,蠕变寿命为62.32 h,稳态蠕变速率为5.545×10-6 mm/s,蠕变性能最优,蠕变断口形貌由解理断裂逐渐转变为韧性断裂。

关键词: Mg-3Al-1Si-xSr合金, 固溶处理, 时效, 组织, 蠕变性能

Abstract: Microstructure of Mg-3Al-1Si alloy was adjusted by Sr microalloying and heat treatment processes (solid solution treatment and aging) to improve the creep properties of the alloy. The results show that the Sr element and solution treatment + aging treatment have a strong refining effect on the as-cast microstructure of the alloy. When the Sr content is 0.4% and the aging time is 24 h, the refining effect is the best. With the increase of Sr content and aging time, the creep life of the alloy increases. But the over-aging occurs when aging for 36 h which results in the decrease of creep life. After 420 ℃×10 h solid solution treatment + 180 ℃×24 h aging, the creep properties of the alloy is the best, with the creep life reaching 62.32 h, the steady-state creep rate reaching 5.545×10-6 mm/s, and the creep fracture morphology gradually changes from cleavage fracture to ductile fracture.

Key words: Mg-3Al-1Si-xSr alloy, solid solution treatment, aging, microstructure, creep properties

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