中国物理B ›› 2013, Vol. 22 ›› Issue (3): 37303-037303.doi: 10.1088/1674-1056/22/3/037303

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Dislocation-mediated creep process in nanocrystalline Cu

穆君伟, 孙世成, 江忠浩, 连建设, 蒋青   

  1. Key Laboratory of Automobile Materials, Department of Materials Science and Engineering, Jilin University, Changchun 130025, China
  • 收稿日期:2012-11-06 修回日期:2012-12-17 出版日期:2013-02-01 发布日期:2013-02-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 50771049 and 50871046) and the National Basic Research Program of China (Grant No. 2010CB 631001).

Dislocation-mediated creep process in nanocrystalline Cu

Mu Jun-Wei (穆君伟), Sun Shi-Cheng (孙世成), Jiang Zhong-Hao (江忠浩), Lian Jian-She (连建设), Jiang Qing (蒋青)   

  1. Key Laboratory of Automobile Materials, Department of Materials Science and Engineering, Jilin University, Changchun 130025, China
  • Received:2012-11-06 Revised:2012-12-17 Online:2013-02-01 Published:2013-02-01
  • Contact: Jiang Zhong-Hao E-mail:jzh@jlu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 50771049 and 50871046) and the National Basic Research Program of China (Grant No. 2010CB 631001).

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摘要： Nanocrystalline Cu with average grain sizes ranging from ～24.4 to 131.3 nm were prepared by electric brush-plating technique. Nanoindentation tests were performed within a wide strain rate range, and the creep process of nanocrystalline Cu during holding period and its relationship to dislocation and twin structures were examined. It was demonstrated that creep strain and creep strain rate are considerably significant for smaller grain size and higher loading strain rate, and are far higher than those predicted by the models of Cobble creep and grain boundary sliding. The analysis based on the calculations and experiments reveals that the significant creep deformation arises from the rapid absorption of high density dislocations stored in loading regime. Our experiments imply that stored dislocations during loading are highly unstable and dislocation activity can proceed and lead to significant post-loading plasticity.

关键词: nanocrystalline, creep, dislocation, nanoindentation

Abstract: Nanocrystalline Cu with average grain sizes ranging from ～24.4 to 131.3 nm were prepared by electric brush-plating technique. Nanoindentation tests were performed within a wide strain rate range, and the creep process of nanocrystalline Cu during holding period and its relationship to dislocation and twin structures were examined. It was demonstrated that creep strain and creep strain rate are considerably significant for smaller grain size and higher loading strain rate, and are far higher than those predicted by the models of Cobble creep and grain boundary sliding. The analysis based on the calculations and experiments reveals that the significant creep deformation arises from the rapid absorption of high density dislocations stored in loading regime. Our experiments imply that stored dislocations during loading are highly unstable and dislocation activity can proceed and lead to significant post-loading plasticity.

Key words: nanocrystalline, creep, dislocation, nanoindentation

中图分类号:  (Nanocrystalline materials)

  • 73.63.Bd
62.20.Hg (Creep) 61.72.Lk (Linear defects: dislocations, disclinations) 62.90.+k (Other topics in mechanical and acoustical properties of condensed matter)