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Title: FEM Modeling of In-Plane Stress Distribution in Thick Brittle Coatings/Films on Ductile Substrates Subjected to Tensile Stress to Determine Interfacial Strength

Abstract

The ceramic-metal interface is present in various material structures and devices that are vulnerable to failures, like cracking, which are typically due to their incompatible properties, e.g., thermal expansion mismatch. In failure of these multilayer systems, interfacial shear strength is a good measure of the robustness of interfaces, especially for planar films. There is a widely-used shear lag model and method by Agrawal and Raj to analyse and measure the interfacial shear strength of thin brittle film on ductile substrates. The use of this classical model for a type of polymer derived ceramic coatings (thickness ~18 μm) on steel substrate leads to high values of interfacial shear strength. Here, we present finite element simulations for such a coating system when it is subjected to in-plane tension. Results show that the in-plane stresses in the coating are non-uniform, i.e., varying across the thickness of the film. Therefore, they do not meet one of the basic assumptions of the classical model: uniform in-plane stress. Furthermore, effects of three significant parameters, film thickness, crack spacing, and Young’s modulus, on the in-plane stress distribution have also been investigated. ‘Thickness-averaged In-plane Stress’ (TIS), a new failure criterion, is proposed for estimating the interfacial shear strength,more » which leads to a more realistic estimation of the tensile strength and interfacial shear strength of thick brittle films/coatings on ductile substrates.« less

Authors:
ORCiD logo [1];  [2];  [3]
  1. Aerospace Research Inst of Materials & Processing Technologies, Beijing (China)
  2. Shanghai Univ. (China). Research Center for Composite Materials, School of Materials Science and Engineering
  3. Clemson Univ., SC (United States). Dept. of Materials Science and Engineering
Publication Date:
Research Org.:
Univ. of Washington Seattle, WA (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
1510461
Grant/Contract Number:  
FE0023142
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Materials
Additional Journal Information:
Journal Volume: 11; Journal Issue: 4; Journal ID: ISSN 1996-1944
Publisher:
MDPI
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; polymer derived ceramic coatings; FEM modelling; thick films; in-plane Stress; interfacial shear strength; crack density

Citation Formats

Wang, Kaishi, Zhang, Fangzhou, and Bordia, Rajendra. FEM Modeling of In-Plane Stress Distribution in Thick Brittle Coatings/Films on Ductile Substrates Subjected to Tensile Stress to Determine Interfacial Strength. United States: N. p., 2018. Web. doi:10.3390/ma11040497.
Wang, Kaishi, Zhang, Fangzhou, & Bordia, Rajendra. FEM Modeling of In-Plane Stress Distribution in Thick Brittle Coatings/Films on Ductile Substrates Subjected to Tensile Stress to Determine Interfacial Strength. United States. doi:10.3390/ma11040497.
Wang, Kaishi, Zhang, Fangzhou, and Bordia, Rajendra. Tue . "FEM Modeling of In-Plane Stress Distribution in Thick Brittle Coatings/Films on Ductile Substrates Subjected to Tensile Stress to Determine Interfacial Strength". United States. doi:10.3390/ma11040497. https://www.osti.gov/servlets/purl/1510461.
@article{osti_1510461,
title = {FEM Modeling of In-Plane Stress Distribution in Thick Brittle Coatings/Films on Ductile Substrates Subjected to Tensile Stress to Determine Interfacial Strength},
author = {Wang, Kaishi and Zhang, Fangzhou and Bordia, Rajendra},
abstractNote = {The ceramic-metal interface is present in various material structures and devices that are vulnerable to failures, like cracking, which are typically due to their incompatible properties, e.g., thermal expansion mismatch. In failure of these multilayer systems, interfacial shear strength is a good measure of the robustness of interfaces, especially for planar films. There is a widely-used shear lag model and method by Agrawal and Raj to analyse and measure the interfacial shear strength of thin brittle film on ductile substrates. The use of this classical model for a type of polymer derived ceramic coatings (thickness ~18 μm) on steel substrate leads to high values of interfacial shear strength. Here, we present finite element simulations for such a coating system when it is subjected to in-plane tension. Results show that the in-plane stresses in the coating are non-uniform, i.e., varying across the thickness of the film. Therefore, they do not meet one of the basic assumptions of the classical model: uniform in-plane stress. Furthermore, effects of three significant parameters, film thickness, crack spacing, and Young’s modulus, on the in-plane stress distribution have also been investigated. ‘Thickness-averaged In-plane Stress’ (TIS), a new failure criterion, is proposed for estimating the interfacial shear strength, which leads to a more realistic estimation of the tensile strength and interfacial shear strength of thick brittle films/coatings on ductile substrates.},
doi = {10.3390/ma11040497},
journal = {Materials},
issn = {1996-1944},
number = 4,
volume = 11,
place = {United States},
year = {2018},
month = {3}
}

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Works referenced in this record:

Mixed Mode Cracking in Layered Materials
book, January 1991