Analysis of spherical indentation of porous ceramic films

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• 作者：Zhangwei Chen^a ; ^{chen@imperial.ac.uk" class="auth_mail" title="E-mail the corresponding author} ; Xin Wang^b ; Nigel Brandon^a ; Alan Atkinson^b
• 关键词：Porous ceramic film ; Indentation ; Finite element modelling ; Deformation ; Mechanical properties
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：37
• 期：3
• 页码：1031-1038
• 全文大小：2304 K

文摘

Spherical indentation of a porous brittle La_0.6Sr_0.4Co_0.2Fe_0.8O₃ ceramic film (porosity = 39.7%) on a stiffer elastic Ce_0.9Gd_0.1O_1.95 substrate is simulated by finite element modelling incorporating the Gurson model to account for densification. The simulated load-displacement curves, apparent elastic modulus E, indentation hardness H and densification profile are all in good agreement with experimental data for the film. The simulations show that E and H are not sensitive to film residual stress. However E is very sensitive to the indent depth-film thickness ratio f, although H is less so for f < 0.3. The simulated dependence of E and H on f are highly consistent with experimental data, supporting the extrapolation of E and H measured for 0.1 < f < 0.3, to zero depth for good estimates of the film-alone properties. The inclusion of densification in the simulation makes only a small difference to E, but has a large influence on H as a function of indentation depth.