کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1669130 1008879 2010 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Fracture behavior of nano-layered coatings under tension
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فناوری نانو (نانو تکنولوژی)
پیش نمایش صفحه اول مقاله
Fracture behavior of nano-layered coatings under tension
چکیده انگلیسی

The fracture of brittle/ductile multilayers composed of equal thicknesses of Si and Ag layers evaporated on a thick substrate is studied with the aid of a four-point bending apparatus. The system variables include individual layer thickness (2.5 to 30 nm), total film thickness (0.5 to 3.5 μm) and substrate material (polycarbonate, aluminum alloy and hard steel). The fracture is characterized by transverse cracks that proliferate with load. The crack initiation strain εi is virtually independent of total film thickness and substrate material while increasing with decreasing layer thickness h, to a good approximation as εi ~ 1/h1/2. At higher strains, film debonding and buckling are evident.The fracture conditions are determined with the aid of a 2D finite element analysis incorporating the inelastic response of the interlayer. A fracture scenario consisting of tunnel cracking in the brittle layers followed by cracking in the interlayers is shown to be capable of predicting the observed increase in crack initiation strain with decreasing layer thickness. To realize this benefit the interlayer must be compliant and tough to force tunnel cracking in the brittle layers. The explicit relation for the crack initiation strain obtained from the analysis can be used to assess fracture toughness and improve damage tolerance in nanoscale layered structures.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thin Solid Films - Volume 519, Issue 1, 29 October 2010, Pages 331–336
نویسندگان
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