Journal
ACTA MATERIALIA
Volume 158, Issue -, Pages 38-52Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.actamat.2018.07.028
Keywords
Medium- and high-entropy alloys; Twinning; Work-hardening modeling; EBSD; Texture
Funding
- National Science Foundation, Division of Materials Research [DMR-60050072]
- National Science Foundation [DGE-1343012]
- Department of Energy National Energy Technology Laboratory [DE-FE0027776]
- U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division
Ask authors/readers for more resources
Texture evolution during room-temperature tensile testing of recrystallized equimolar CrCoNi was studied using electron backscatter diffraction and electron channeling contrast imaging on specimens from interrupted tests. Dominant deformation mechanisms included slip at low strains and deformation twinning at larger strains, which were accompanied by the development of a strong < 111 > texture parallel to the tensile axis. Highly deformed material also contained nanotwin/hcp lamellae, which have previously been hypothesized to act as potent barriers for non-coplanar dislocations. To examine this hypothesis, mean-field modeling was performed using the viscoplastic self-consistent framework with varying ratios for hardening by slip and twinning. In the optimal model, twinning produced approximately three times as much non-coplanar hardening as slip, which is larger than previous observations in other twinning-induced plasticity materials that do not form twin/hcp lamellae. Additional full-field elasto-viscoplastic simulations were performed using the fast Fourier transform (EVP-FFT) method to examine intragranular rotation and the effect of initial grain orientation on the deformation mode. Grains with initial orientations near < 111 > had the greatest propensity for deformation twinning while grains near < 100 > were more likely to deform by slip even at large strains. Excellent quantitative agreement was obtained between the experiments and EVP-FFT model. (C) 2018 Published by Elsevier Ltd on behalf of Acta Materialia Inc.
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