skip to main content

DOE PAGESDOE PAGES

Title: A multi-scale model of dislocation plasticity in α-Fe: Incorporating temperature, strain rate and non-Schmid effects

In this study, we develop an atomistically informed crystal plasticity finite element (CP-FE) model for body-centered-cubic (BCC) α-Fe that incorporates non-Schmid stress dependent slip with temperature and strain rate effects. Based on recent insights obtained from atomistic simulations, we propose a new constitutive model that combines a generalized non-Schmid yield law with aspects from a line tension (LT) model for describing activation enthalpy required for the motion of dislocation kinks. Atomistic calculations are conducted to quantify the non-Schmid effects while both experimental data and atomistic simulations are used to assess the temperature and strain rate effects. The parameterized constitutive equation is implemented into a BCC CP-FE model to simulate plastic deformation of single and polycrystalline Fe which is compared with experimental data from the literature. This direct comparison demonstrates that the atomistically informed model accurately captures the effects of crystal orientation, temperature and strain rate on the flow behavior of siangle crystal Fe. Furthermore, our proposed CP-FE model exhibits temperature and strain rate dependent flow and yield surfaces in polycrystalline Fe that deviate from conventional CP-FE models based on Schmid's law.
Authors:
 [1] ;  [2] ;  [3] ;  [1] ;  [4]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. National Institute of Standards and Technology, Gaithersburg, MD (United States)
  3. Sandia National Lab. (SNL-CA), Livermore, CA (United States)
  4. Drexel Univ., Philadelphia, PA (United States)
Publication Date:
OSTI Identifier:
1258482
Report Number(s):
SAND--2014-15610J
Journal ID: ISSN 0749-6419; PII: S0749641914002356
Grant/Contract Number:
AC04-94AL85000
Type:
Accepted Manuscript
Journal Name:
International Journal of Plasticity
Additional Journal Information:
Journal Volume: 73; Journal Issue: C; Journal ID: ISSN 0749-6419
Publisher:
Elsevier
Research Org:
Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE Fe; non-Schmid; temperature; strain rate; molecular dynamics; crystal plasticity