Journal
ACTA MATERIALIA
Volume 228, Issue -, Pages -Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2022.117787
Keywords
Internal friction; Ferroelastic materials; Twins; Vacancy pinning; Avalanches
Funding
- National Natural Science Foundation of China [51931004]
- 111 project 2.0 [BP2018008]
- Spanish AEI
- FEDER, UE [RTI 2018-094683-BC51]
- EPSRC
- EU [EP/P024904/1, EU 861153]
Ask authors/readers for more resources
This study presents the first attempt to investigate the internal friction of complex ferroelastic twin patterns using atomistic molecular dynamics simulations. Linear and non-linear internal friction regimes are observed at different stress amplitudes, separated by a pinning/depinning threshold. The motion of twin boundaries generates non-linear anelasticity, where the stress-dependent internal friction increases to a maximum and then decays. The internal friction is directly related to the motion of needle twins.
We report the first attempt to study the internal friction (IF) of complex ferroelastic twin patterns by atomistic molecular dynamics simulations. At different stress amplitudes, linear and non-linear IF regimes are observed. They are separated by a pinning/depinning threshold. At external stresses below the pinning/depinning threshold, a low linear IF background is nearly independent of temperature and configuration of the twin patterns. With increasing stresses, twin boundary motions generate non-linear anelasticity where the stress dependent IF increases to a maximum and then decays. The IF is directly related to the motion of needle twins. The effects of vacancy pinning and thermal activation are studied. The IF maximum is reduced and shifted to higher stresses by extrinsic pinning effects. The IF maximum decreases further with increasing temperature from 8 x 10(-6) T-c to 8 x 10(-4) T-c where T-c is the ferroelastic transition temperature. The non-linear IF depends by power law on the strain with exponents near 2 below the IF maximum and-1 at strains higher than the maximum. Vacancies destroy the power law and break the scale invariance of the domain boundary movements. The overall picture obtained in this study is consistent with basic experimental observations. (c) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available