Micromechanical Fields Associated with Irregular Deformation Twins in Magnesium

Brandon Leu, M. Arul Kumar, Paul F. Rottmann, Kevin J. Hemker, Irene J. Beyerlein

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

Understanding and controlling the development of deformation twins is paramount for engineering strong and stable hexagonal close-packed (HCP) Mg alloys. Actual twins are often irregular in boundary morphology and twin crystallography, deviating from the classical picture commonly used in theory and simulation. In this work, the elastic strains and stresses around irregular twins are examined both experimentally and computationally to gain insight into how twins develop and the microstructural features that influence their development. A nanoprecession electron diffraction (N-PED) technique is used to measure the elastic strains within and around a { 10 1 ¯ 2 } tensile twin in AZ31B Mg alloy with nm scale resolution. A full-field elasto-viscoplastic fast Fourier transform (EVP-FFT) crystal plasticity model of the same sub-grain and irregular twin structure is employed to understand and interpret the measured elastic strain fields. The calculations predict spatially resolved elastic strain fields in good agreement with the measurement, as well as all the stress components and the dislocation density fields generated by the twin, which are not easily obtainable from the experiment. The model calculations find that neighboring twins, several twin thicknesses apart, have little influence on the twin-tip micromechanical fields. Furthermore, this work reveals that irregularity in the twin-tip shape has a negligible effect on the development of the elastic strains around and inside the twin. Importantly, the major contributor to these micromechanical fields is the alignment of the twinning shear direction with the twin boundary.

Original languageEnglish
Pages (from-to)2688-2699
Number of pages12
JournalJournal of Materials Engineering and Performance
Volume32
Issue number6
DOIs
StatePublished - Mar 2023

Bibliographical note

Publisher Copyright:
© 2022, The Author(s).

Keywords

  • N-PED
  • crystal plasticity
  • deformation twin
  • local strain
  • magnesium

ASJC Scopus subject areas

  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Micromechanical Fields Associated with Irregular Deformation Twins in Magnesium'. Together they form a unique fingerprint.

Cite this