Delamination of Thin Films From Two-Dimensional Interface Flaws at Corners and Edges
Delamination of Thin Films From Two-Dimensional Interface Flaws at Corners and Edges
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角落和边缘处的二维界面缺陷导致薄膜分层
DOI：
10.1023/a:1013523927893
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
J. M. Ambrico
中科院分区：
文献类型：
--
作者：
M. Begley;J. M. Ambrico
本文详细介绍了由二维界面缺陷的热膨胀失配驱动的薄膜分层的机制。考虑了两种情况：（i）膜的边缘与基底的边缘重合，和（ii）基底延伸超过膜的边缘。全三维有限元模型用于分析两种情况下的半圆形界面缺陷（沿着边缘）或四分之一圆界面缺陷（在膜的拐角处）。结果提出了能量释放率和模式混合沿着二维裂纹前沿。对于所考虑的所有情况，非常接近裂纹前沿和薄膜边缘交叉点的裂纹驱动力远大于裂纹前沿内部的裂纹驱动力。对于给定的裂纹尺寸，当基底延伸超过膜的端部时，沿着整个前部沿着的能量释放率较高。的应力强度因子是混合模式沿着整个裂纹前端的预测表明，模式III组件包括一个重大贡献的裂纹驱动力在一个显着的部分裂纹前端。薄膜脱层的结果的影响进行了讨论的临界缺陷尺寸，裂纹前缘轮廓和交叉奇异性的影响。
This paper details the mechanics governing delamination of thin films driven by thermal expansion mismatch from two-dimensional interface flaws. Two scenarios are considered: (i) the edge of the film is concurrent with the edge of the substrate and (ii) the substrate extends past the edge of the film. Fully three-dimensional finite element models are used to analyze semi-circular interface flaws (along the edge) or quarter-circle interface flaws (at the corner of the film) for both scenarios. Results are presented for energy release rates and mode-mixity along two-dimensional crack fronts. For all cases considered, the crack driving force very close to the intersection of the crack front and the edge of the film is substantially larger than that for the interior portions of the crack front. For a given flaw size, the energy release rate along the entire front is higher when the substrate extends past the end of the film. The stress intensity factors are mixed-mode along the entire crack front; the predictions illustrate that the mode III component comprises a substantial contribution to the crack driving force over a significant part of the crack front. The implications of the results on film delamination is discussed in terms of critical flaw sizes, crack front profiles and the influence of the intersection singularity.