کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
279710 | 1430353 | 2008 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Brittle versus ductile transition of nanocrystalline metals Brittle versus ductile transition of nanocrystalline metals](/preview/png/279710.png)
The brittle versus ductile transition for conventional metals is dictated by the competition between dislocation emission and cleavage. For nanocrystalline metals with grain size below 25 nm, however, dislocation activities are suppressed and the classic theory fails to apply. In this paper, one of the competing mechanisms that control the brittle versus ductile transition of nanocrystalline metals is found to be the grain boundary dominated creep deformation versus the grain boundary decohesion. A model is proposed to quantify the crack propagation in nanocrystalline metals. The effects of material properties, initial configuration and applied loads on the property of crack propagation are addressed. It is concluded that either the increases in the initial crack length, the applied load and the grain boundary damage, or the deterrence in creep deformation, accelerate the crack propagation, and vice versa.
Journal: International Journal of Solids and Structures - Volume 45, Issue 13, 30 June 2008, Pages 3897–3907