Disappearance of stress singularity at interface edge due to nanostructured thin film
Disappearance of stress singularity at interface edge due to nanostructured thin film
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DOI：
10.1016/j.engfracmech.2007.12.010
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发表时间：
2008-07-01
影响因子：
5.4
通讯作者：
Kitamura, Takayuki
中科院分区：
文献类型：
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作者：
Sumigawa, Takashi;Hirakata, Hiroyuki;Kitamura, Takayuki
本研究的目的是研究纳米结构薄膜与固体之间的界面附近的应力分布。我们专注于一个纳米结构的薄膜，包括Ta 2 O 5螺旋纳米弹簧制作石油硅衬底上的动态倾斜沉积。薄膜的机械性能是通过垂直和横向加载测试，使用金刚石针尖内置到原子力显微镜。薄膜的表观剪切模量和杨氏模量C和E比常规固体Ta 2 O 5薄膜低2-3个数量级。此外，薄膜显示出强的各向异性。本文对弹性固体中薄膜与基体界面边界不同的两类构件在均匀位移作用下进行了有限元分析。一种是表面-界面夹角为90 ° ~ 90 °的自由边，另一种是界面短裂纹。这些分析表明，不仅没有应力奇异性，而且在自由边和界面裂纹尖端附近也没有高应力集中。界面附近的特征应力分布是由于薄膜的纳米级离散结构。(c)2008爱思唯尔有限公司保留所有权利。
The purpose of this study is to examine the stress distribution near the interface between a nanostructured thin film and a solid body. We focus on a nanostructured thin film that consists of Ta2O5 helical nanosprings fabricated oil a Si substrate by dynamic oblique deposition. The mechanical properties of the thin film are obtained by vertical and lateral loading tests using a diamond tip built into an atomic force microscope. The apparent shear and Young's moduli, C and E, of the thin film are 2-3 orders of magnitude lower than those of a conventional solid Ta2O5 film. Moreover, the thin film shows strong anisotropy. A finite element analysis for two types of components with different interface edges between the thin film and,in elastic solid body is conducted under uniform displacement. One has a free edge where the surface-interface angle is 90 degrees-90 degrees, and the other has a short interface crack. These analyses indicate the absence of not only stress singularity but also high stress concentration near the free edge and the interface crack tip. The characteristic stress distributions near the interface are due to the nanoscopically discrete structure of the thin film. (c) 2008 Elsevier Ltd. All rights reserved.