文章基本信息

标题：Theoretical Investigation of the Displacement Burst Observed in Nanoindentation by Collective Dislocation Loops Nucleation Model
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作者：Tomohito TSURU ; Yoji SHIBUTANI
期刊名称：Journal of Computational Science and Technology
电子版ISSN：1881-6894
出版年度：2008
卷号：2
期号：4
页码：559-567
DOI：10.1299/jcst.2.559
出版社：The Japan Society of Mechanical Engineers
摘要：Abrupt growth of displacement observed in the relationship between indent load and indent depth in nanoindentation of crystalline materials, so-called displacement burst, has been recognized as one of the representative examples of nanoscale plastic behavior (nanoplasticity). This phenomenon corresponds to the early stage of plastic deformation and is greatly influenced by the collective dislocation emission. In the present paper a simplified model is constructed for the first displacement burst with use of the elastic theory based on both the Hertzian contact theory and the classical dislocation theory to evaluate the displacement burst in nanoindentation. The result of the analytical model for the energy equilibrium revealed that there is a strong correlation between burst width and critical indent depth that corresponds to the dislocation emission. Finally, it is shown that more than one hundred high-density dislocations are generated simultaneously and surface step corresponding to the Burgers vector of dislocation dipole of each emitted dislocation causes significant displacement burst.
关键词：Nanoindentation;Displacement Burst;Collective Dislocation Emission;Elastic Theory of Dislocations