skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Twin formation from a twin boundary in Mg during in-situ nanomechanical testing

Abstract

An important fundamental question regarding deformation twinning is whether it is possible for twins to nucleate at boundaries or interfaces when specific stress fields are present. A corollary that follows from this question is: if this is indeed possible, what determines the proper stress field and how does it occur at the nanoscale? Here, we demonstrate the application of an in-situ nanoindentation approach to confine and dynamically capture the stages in the formation of a deformation twin at an internal twin boundary in single crystal Mg. We observe the formation of contraction twin embryos at the pre-existing extension twin boundary, and the subsequent propagation of the twin embryos into the crystal. We reveal an intermediate step, involving the coalescence of tiny embryos into a larger embryo before the nucleus emanates into the crystal. De-twinnning of the twin embryos is captured during unloading and shown to leave a remnant nanosized twin (<10 nm) after complete unloading. A 3D full-field, crystal plasticity model identifies that the twin type and variant selection of the stable embryo are governed by the internal local stress state prevailing at the pre-existing twin boundary. The possible role played by dislocations and boundary structure (incoherent vs. coherent) inmore » embryo formation, as suggested by the TEM and modeling analyses, are discussed.« less

Authors:
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [4];  [8];  [4];  [4]
  1. Thermo Fisher Scientific
  2. Los Alamos National Laboratory
  3. University of California, Santa Barbara
  4. University of California, Irvine
  5. BATTELLE (PACIFIC NW LAB)
  6. Wuhan University of Technology
  7. California Polytechnic State University
  8. University of California, Davis
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1567203
Report Number(s):
PNNL-SA-147524
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Materials Science and Engineering. A. Structural Materials: Properties, Microstructure and Processing
Additional Journal Information:
Journal Volume: 759
Country of Publication:
United States
Language:
English
Subject:
grains and interfaces, magnesium alloys, plasticity, modeling/simulations, characterization

Citation Formats

Jiang, Lin, Kumar, Mariyappan A., Beyerlein, Irene J., Wang, Xin, Zhang, Dalong, Wu, Chuandong, Cooper, Chase, Rupert, Timothy J., Mahajan, Subhash, Lavernia, Enrique J., and Schoenung, Julie M. Twin formation from a twin boundary in Mg during in-situ nanomechanical testing. United States: N. p., 2019. Web. doi:10.1016/j.msea.2019.04.117.
Jiang, Lin, Kumar, Mariyappan A., Beyerlein, Irene J., Wang, Xin, Zhang, Dalong, Wu, Chuandong, Cooper, Chase, Rupert, Timothy J., Mahajan, Subhash, Lavernia, Enrique J., & Schoenung, Julie M. Twin formation from a twin boundary in Mg during in-situ nanomechanical testing. United States. doi:10.1016/j.msea.2019.04.117.
Jiang, Lin, Kumar, Mariyappan A., Beyerlein, Irene J., Wang, Xin, Zhang, Dalong, Wu, Chuandong, Cooper, Chase, Rupert, Timothy J., Mahajan, Subhash, Lavernia, Enrique J., and Schoenung, Julie M. Mon . "Twin formation from a twin boundary in Mg during in-situ nanomechanical testing". United States. doi:10.1016/j.msea.2019.04.117.
@article{osti_1567203,
title = {Twin formation from a twin boundary in Mg during in-situ nanomechanical testing},
author = {Jiang, Lin and Kumar, Mariyappan A. and Beyerlein, Irene J. and Wang, Xin and Zhang, Dalong and Wu, Chuandong and Cooper, Chase and Rupert, Timothy J. and Mahajan, Subhash and Lavernia, Enrique J. and Schoenung, Julie M.},
abstractNote = {An important fundamental question regarding deformation twinning is whether it is possible for twins to nucleate at boundaries or interfaces when specific stress fields are present. A corollary that follows from this question is: if this is indeed possible, what determines the proper stress field and how does it occur at the nanoscale? Here, we demonstrate the application of an in-situ nanoindentation approach to confine and dynamically capture the stages in the formation of a deformation twin at an internal twin boundary in single crystal Mg. We observe the formation of contraction twin embryos at the pre-existing extension twin boundary, and the subsequent propagation of the twin embryos into the crystal. We reveal an intermediate step, involving the coalescence of tiny embryos into a larger embryo before the nucleus emanates into the crystal. De-twinnning of the twin embryos is captured during unloading and shown to leave a remnant nanosized twin (<10 nm) after complete unloading. A 3D full-field, crystal plasticity model identifies that the twin type and variant selection of the stable embryo are governed by the internal local stress state prevailing at the pre-existing twin boundary. The possible role played by dislocations and boundary structure (incoherent vs. coherent) in embryo formation, as suggested by the TEM and modeling analyses, are discussed.},
doi = {10.1016/j.msea.2019.04.117},
journal = {Materials Science and Engineering. A. Structural Materials: Properties, Microstructure and Processing},
number = ,
volume = 759,
place = {United States},
year = {2019},
month = {6}
}