کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10620429 | 988622 | 2011 | 12 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Length-scale-dependent deformation and fracture behavior of Cu/X (XÂ =Â Nb, Zr) multilayers: The constraining effects of the ductile phase on the brittle phase
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The plastic deformation and fracture behavior of two different types of Cu/X (X = Nb, Zr) nanostructured multilayered films (NMFs) were systematically investigated over wide ranges of modulation period (λ) and modulation ratio (η, the ratio of X layer thickness to Cu layer thickness). It was found that both the ductility and fracture mode of the NMFs were predominantly related to the constraining effect of ductile Cu layers on microcrack-initiating X layers, which showed a significant length-scale dependence on λ and η. Experimental observations and theoretical analyses also revealed a transition in strengthening mechanism, from single dislocation slip in confined layers to a load-bearing effect, when the Cu layer thickness was reduced to below â¼15 nm by either decreasing λ or increasing η. This is due to the intense suppression of dislocation activities in the thin Cu layers, which causes a remarkable reduction in the deformability of the Cu layers. Concomitantly, the constraining effect of Cu layers on microcrack propagation is weakened, which can be used to explain the experimentally observed λ and η-dependent fracture mode transition from shear mode to an opening mode. Furthermore, the fracture toughness of the NMFs is also found to be sensitive to both λ and η. A fracture mechanism-based micromechanical model is developed to quantitatively assess the length-scale-dependent fracture toughness, and these calculations are in good agreement with experimental findings.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 59, Issue 19, November 2011, Pages 7368-7379
Journal: Acta Materialia - Volume 59, Issue 19, November 2011, Pages 7368-7379
نویسندگان
J.Y. Zhang, X. Zhang, R.H. Wang, S.Y. Lei, P. Zhang, J.J. Niu, G. Liu, G.J. Zhang, J. Sun,