Tan Rongkai, Wang Zhanfeng, Wu Shilei, Liu Weili, Jiang Beibei
Key Laboratory of Conveyance Equipment (East China Jiaotong University), Ministry of Education, Nanchang 330013, People's Republic of China.
School of Mechanical and Electrical Engineering, Suqian University, Suqian 223800, People's Republic of China.
Nanotechnology. 2023 Sep 1;34(46). doi: 10.1088/1361-6528/acf0c9.
The mechanical properties of crystalline materials are influenced by their deformation behavior, which is associated with their microstructural characteristics. Specifically, crystallographic orientation greatly affects the microscale plastic deformation of individual grains. In this study, experiments and finite element simulations of Berkovich nanoindentations are conducted to investigate the impact of crystallographic orientation in polycrystalline copper. A crystal plasticity constitutive model is developed for copper materials, which accurately captures their indentation mechanical response. The results showed that the indentation behavior of polycrystalline copper exhibits a high degree of anisotropy due to significant variation in slip systems for different crystallographic orientations. This results in different mechanical responses of individual grains and distinct material pileup morphologies on the indented surface. Additionally, the study revealed that crystallographic orientation plays a critical role in determining the indentation size effect. These findings have important implications for the design of materials where plasticity is a crucial factor.
晶体材料的力学性能受其变形行为影响，而变形行为与其微观结构特征相关。具体而言，晶体取向极大地影响单个晶粒的微观尺度塑性变形。在本研究中，进行了Berkovich纳米压痕实验和有限元模拟，以研究晶体取向对多晶铜的影响。针对铜材料开发了晶体塑性本构模型，该模型能准确捕捉其压痕力学响应。结果表明，由于不同晶体取向的滑移系存在显著差异，多晶铜的压痕行为表现出高度各向异性。这导致单个晶粒的力学响应不同，以及压痕表面出现明显不同的材料堆积形态。此外，研究表明晶体取向在确定压痕尺寸效应方面起着关键作用。这些发现对塑性是关键因素的材料设计具有重要意义。
