Precise measurement of activation parameters for individual dislocation nucleation during in situ TEM tensile testing of single crystal nickel

SCRIPTA MATERIALIA

卷:197

Article

Li, Xiaoqing^1,2  Minor, Andrew M.^1,2 

[1] Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA

[2] Lawrence Berkeley Natl Lab, Mol Foundry, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA

关键词: In situ TEM;    Nanomechanical testing;    Dislocation plasticity;    Dislocation nucleation;    Activation volume;   

DOI  :  10.1016/j.scriptamat.2021.113764

来源: Elsevier

【 摘 要 】

Nucleation of crystalline defects such as dislocations lies at the heart of mechanical deformation. Here, we demonstrate a technique for observing the nucleation of individual dislocations during in situ transmission electron microscopy (TEM) tensile testing and measuring fundamental parameters relevant for plasticity from the individual events. Our method relies on systematic detection of dislocation slip traces with automated image analysis in an oriented single crystal Ni sample. Using the identification of individual defect traces from in situ testing, a cumulative probabilistic function is applied to correlate the relationship between a dislocation nucleation event and the corresponding stress level. Our analysis allows for the extrapolation of the activation parameters for individual dislocation nucleation events using the data on one sample in one tensile test. Precise and quantitative correlation of activation parameters for dislocation nucleation from in situ TEM nanomechanical testing can provide direct quantitative measurements useful for computational models of plasticity. ? 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

【 授权许可】

Free