Depth-sensing ductile and brittle deformation in 3C-SiC under Berkovich nanoindentation
Depth-sensing ductile and brittle deformation in 3C-SiC under Berkovich nanoindentation
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DOI：
10.1016/j.matdes.2020.109223
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发表时间：
2021-01-01
影响因子：
8.4
通讯作者：
Hartmaier, Alexander
中科院分区：
文献类型：
--
作者：
Zhao, Liang;Zhang, Junjie;Hartmaier, Alexander
在硬脆材料中，韧性变形模式和脆性变形模式之间的相互作用表现出强烈的尺寸效应。本文通过有限元模拟和相应的实验研究，阐明了单晶3C-SiC在布氏纳米压痕下压痕深度相关的变形机制。建立了一种新的有限元框架，该框架结合了描述位错滑移延性变形的晶体塑性本构模型和描述裂纹萌生和扩展诱发脆性断裂的内聚区模型。根据相应的Berkovich纳米压痕实验获得的载荷-位移曲线，标定了3C-SiC晶体塑性模型中所用的参数。随后的有限元模拟和纳米压痕实验共同揭示了3C-SiC在不同压痕深度下的微观塑性变形和脆性断裂共存，这显著影响了所观察到的宏观力学响应和表面堆积形貌。特别是，在压痕深度为500 nm的表面裂纹的预测形态与实验观察一致，并从理论上分析了裂纹萌生和扩展与表面堆积形貌的相关性。(c)2020作者（S）由爱思唯尔有限公司出版。这是一篇在CC BY-NC-ND许可证下的开放获取文章（http：//creativecommons.org/licenses/by-nc-nd/4.0/）。
The interplay between ductile and brittle deformation modes in hard brittle materials exhibits a strong size effect. In the present work, indentation depth-dependent deformation mechanisms of single-crystal 3C-SiC under Berkovich nanoindentation are elucidated by finite element simulations and corresponding experiments. A novel finite element framework, that combines a crystal plasticity constitutive model for describing dislocation slip-based ductile deformation and a cohesive zone model for capturing crack initiation and propagationinduced brittle fracture, is established. The utilized parameters in the crystal plasticity model of 3C-SiC are calibrated according to the load-displacement curves obtained from corresponding Berkovich nanoindentation experiments. Subsequent finite element simulations and experiments of nanoindentation jointly reveal coexisting microscopic plastic deformation and brittle fracture of 3C-SiC at different indentation depths, which significantly affect the observed macroscopic mechanical response and surface pile-up topography. In particular, the predicted morphology of surface cracks at an indentation depth of 500 nm agrees well with experimental observation, and the correlation of crack initiation and propagation with surface pile-up topography is theoretically analyzed. (c) 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).