Detwinning mechanisms for growth twins in face-centered cubic metals

被引：537

作者：

Wang, J. ^{[1
]}

Li, N. ^{[2
]}

Anderoglu, O. ^{[2
]}

Zhang, X. ^{[2
]}

Misra, A. ^{[1
]}

Huang, J. Y. ^{[3
]}

Hirth, J. P. ^{[1
]}

机构：

[1] Los Alamos Natl Lab, Los Alamos, NM 87545 USA

[2] Texas A&M Univ, Dept Mech Engn, Mat Sci & Engn Program, College Stn, TX 77843 USA

[3] Sandia Natl Labs, Albuquerque, NM 87185 USA

来源：

ACTA MATERIALIA | 2010年 / 58卷 / 06期

基金：

美国国家科学基金会;

关键词：

Nanotwins; Detwinning; In situ TEM; Atomistic simulations; ULTRAHIGH-STRENGTH; DISLOCATIONS; DYNAMICS;

D O I：

10.1016/j.actamat.2009.12.013

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Using in situ transmission electron microscopy, we studied the stability of growth twins. We observed the rapid migration of incoherent twin boundaries (ITBs), indicating that nanotwins are unstable. Topological analysis and atomistic simulations are adopted to explore detwinning mechanisms. The results show that: (i) the detwinning process is accomplished via the collective glide of multiple twinning dislocations that form an ITB; (ii) detwinning can easily occur for thin twins, and the driving force is mainly attributed to a variation of the excess energy of a coherent twin boundary; (iii) shear stresses enable ITBs to migrate easily, causing the motion of coherent twin boundaries; and (iv) the migration velocity depends on stacking fault energy. The results imply that detwinning becomes the dominant deformation mechanism for growth twins of the order of a few nanometers thick. Published by Elsevier Ltd. on behalf of Acta Materialia Inc.

引用

页码：2262 / 2270

页数：9

共 35 条

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