کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1447736 | 988652 | 2010 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Detwinning mechanisms for growth twins in face-centered cubic metals Detwinning mechanisms for growth twins in face-centered cubic metals](/preview/png/1447736.png)
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.
Journal: Acta Materialia - Volume 58, Issue 6, April 2010, Pages 2262–2270