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Title: Effect of irradiation on mechanical properties of symmetrical grain boundaries investigated by atomic simulations

Authors:
; ; ORCiD logo; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1397803
Grant/Contract Number:
AC06-76RLO 1830
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 491; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 22:20:04; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Wang, X. Y., Gao, N., Setyawan, W., Xu, B., Liu, W., and Wang, Z. G. Effect of irradiation on mechanical properties of symmetrical grain boundaries investigated by atomic simulations. Netherlands: N. p., 2017. Web. doi:10.1016/j.jnucmat.2017.04.051.
Wang, X. Y., Gao, N., Setyawan, W., Xu, B., Liu, W., & Wang, Z. G. Effect of irradiation on mechanical properties of symmetrical grain boundaries investigated by atomic simulations. Netherlands. doi:10.1016/j.jnucmat.2017.04.051.
Wang, X. Y., Gao, N., Setyawan, W., Xu, B., Liu, W., and Wang, Z. G. 2017. "Effect of irradiation on mechanical properties of symmetrical grain boundaries investigated by atomic simulations". Netherlands. doi:10.1016/j.jnucmat.2017.04.051.
@article{osti_1397803,
title = {Effect of irradiation on mechanical properties of symmetrical grain boundaries investigated by atomic simulations},
author = {Wang, X. Y. and Gao, N. and Setyawan, W. and Xu, B. and Liu, W. and Wang, Z. G.},
abstractNote = {},
doi = {10.1016/j.jnucmat.2017.04.051},
journal = {Journal of Nuclear Materials},
number = C,
volume = 491,
place = {Netherlands},
year = 2017,
month = 8
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on May 12, 2018
Publisher's Accepted Manuscript

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  • Tensile response of irradiated symmetric grain boundaries to externally applied strain has been studied using atomic simulation methods. The absorption of irradiation induced defects by grain boundaries has been confirmed to degrade the mechanical properties of grain boundaries through the change of its under- taken deformation mechanism. Atomic rearrangement, the formations of a stress accumulation region and vacancy-rich zone and the nucleation and movement of dislocations under stress effect have been observed after the displacement cascades in grain boundaries, which are considered as main reasons to induce above degradation. These results suggest the necessity of considering both trap- ping efficiencymore » to defects and the mechanical property change of irradiated grain boundaries for further development of radiation resistant materials.« less
  • Atomic structures and energies of symmetrical {l_angle}001{r_angle} tilt grain boundaries (GB{close_quote}s) in diamond have been calculated over a wide range of misorientation angle using a many-body analytic potential, and for some selected short-period grain boundaries with tight-binding and first-principles density-functional methods. The grain boundary energies from the tight-binding and first-principles methods are about 75{percent} of those calculated with the analytic bond-order potential. The energy rankings of the GB{close_quote}s calculated with the empirical potential, however, are similar to that calculated from the tight-binding and the density functional approaches. Atomic-level energy and stress distributions calculated with the bond-order potential reveal relations betweenmore » local interface reconstruction and the extent and value of hydrostatic and shear stresses. From the calculated local volume strain and hydrostatic stress fields, the atomic bulk moduli are evaluated, and zones of different elastic behavior in the vicinity of the interface are defined. {copyright} {ital 1999} {ital The American Physical Society}« less
  • The matrix phase of 93W-5.6Ni-1.4Fe heavy alloy has penetrated into W/W grain boundaries during a newly developed heat treatment which consists of repeated isothermal holdings at 1,150 C and water quenching between them. With the matrix penetration, the impact energy increases from 57 to 170 J, whereas the ultimate tensile strength and elongation remain unchanged. The tensile fracture surface of specimens appears similar regardless of the matrix penetration: predominant cleavage of W grains and dimple fracture of matrix. The fracture surface by impact, on the other hand, reveals a change of W/W interface failure toward ductile failure of penetrated matrixmore » with many dimples by increasing the matrix penetration. The increase in the fraction of ductile failure and observed crack blunting is attributed to the increase in impact energy with the matrix penetration.« less
  • The relaxed structure and energy of the (310) symmetrical tilt grain boundary (STGB) in SrTiO{sub 3} have been calculated using static lattice energy minimization methods. In principle, the (310) GB plane can either be a cation-rich, positively charged 'SrTiO' plane or a negatively charged oxygen plane, and both scenarios have been considered in this report. The effect of point-defect reconstruction at the GB core region, manifested either as completely missing columns or as half-filled columns of ions as suggested by experiments, has been analyzed. The results indicate that while Schottky defects are very strongly preferred energetically at the GB core,more » there is not significant gain in energy by having half-filled columns, as opposed to fully-dense and fully-empty columns, at the GB core. The simulation results have been analyzed in the context of Pauling's rules of crystal chemistry and bicrystallography. The results form the basis for an objective comparison with experimental studies in Part II of the paper.« less
  • The mechanical behavior of individual grain boundaries in boron-free Ni[sub 3]Al was investigated using miniaturized disk-bend tests performed on specimens 3 mm in diameter and nominally 200 [mu]m thick. A directionally-solidified ingot containing 24 at.% Al was annealed between 1,300 and 1,350C to produce an average grain size well over 1 mm, and fifteen disk specimens were extracted from it such that one long grain boundary extended across the diameter of each disk. Electron channeling patterns were used to determine the relative orientation of the grains on either side of the boundary. Low-angle boundaries are so strong they do notmore » fracture, whereas high-angle boundaries always fracture, as indicated by a load drop in the curve of load vs displacement. Considerable plastic deformation of the individual grains occurs in all tests regardless of grain boundary character. Slip traces were observed on many of the grain-boundary fracture surfaces, providing some evidence for slip transmission across high-angle boundaries. The relative fracture strengths of the high-angle boundaries were estimated by extrapolating the elastic portion of the load-displacement curves to the displacement at fracture, yielding values ranging from about 2 to 4 GPa, with an average of 3.06 [plus minus] 0.71 GPa. These are roughly an order of magnitude smaller than the fracture strengths of special boundaries predicted by computer simulations. No correlation was found between the fracture stresses and the relative orientations of the high-angle boundaries, as defined by the coincidence site lattice model.« less