TY - JOUR
T1 - Fracture toughness of the Fe-Zn intermetallic compounds measured by bend testing of chevron-notched single-crystal microbeams
AU - Okamoto, Norihiko L.
AU - Michishita, Shota
AU - Hashizume, Yukichika
AU - Inui, Haruyuki
N1 - Funding Information:
This work was supported by JSPS KAKENHI grant numbers 16H04516, 16K14373, 16K14415 and 15H02300, and the Elements Strategy Initiative for Structural Materials (ESISM) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, and in part by Advanced Low Carbon Technology Research and Development Program (ALCA) from the Japan Science and Technology Agency (JST). This work was also supported by Innovative Program for Advanced Technology as well as 20th and 24th Research Promotion Grant from the Iron and Steel Institute of Japan (ISIJ). A part of this work has been performed under the inter-university cooperative research program of the Center for Computational Materials Science, Institute for Materials Research, Tohoku University (Proposal No. 17S0410).
Publisher Copyright:
© 2018 Iron and Steel Institute of Japan. All rights reserved.
PY - 2018/9/15
Y1 - 2018/9/15
N2 - The fracture toughness values of the five intermetallic compounds in the Fe-Zn system have been investigated through bend testing of chevron-notched single-crystal microbeams. The intermetallic compounds of the Fe-lean phases,1p and , exhibit fracture toughness values higher than the other compounds of the Fe-rich phases, ,1, and1k. The1p-phase compound exhibits a strong anisotropy in fracture toughness while the other four compounds exhibit almost no anisotropy. The compositional dependence of fracture toughness is discussed in terms of the surface energies estimated by ab initio calculations as well as the capability of stress relaxation around a crack by dislocation emission. The phase with a relatively wide solid solubility range exhibits no compositional dependence of the fracture toughness. The fracture toughness value of -phase microbeams that include a grain boundary at the chevron-notch position is comparable to that of the -phase single-crystal microbeams, indicating that the grain boundaries in the phase may not be particularly weak.
AB - The fracture toughness values of the five intermetallic compounds in the Fe-Zn system have been investigated through bend testing of chevron-notched single-crystal microbeams. The intermetallic compounds of the Fe-lean phases,1p and , exhibit fracture toughness values higher than the other compounds of the Fe-rich phases, ,1, and1k. The1p-phase compound exhibits a strong anisotropy in fracture toughness while the other four compounds exhibit almost no anisotropy. The compositional dependence of fracture toughness is discussed in terms of the surface energies estimated by ab initio calculations as well as the capability of stress relaxation around a crack by dislocation emission. The phase with a relatively wide solid solubility range exhibits no compositional dependence of the fracture toughness. The fracture toughness value of -phase microbeams that include a grain boundary at the chevron-notch position is comparable to that of the -phase single-crystal microbeams, indicating that the grain boundaries in the phase may not be particularly weak.
KW - Ab initio calculations
KW - Crystal anisotropy
KW - Electron back scatter diffraction
KW - Focused ion beam
KW - Galvannealed steel
KW - Grain boundary
KW - Surface energy
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U2 - 10.2355/isijinternational.ISIJINT-2018-068
DO - 10.2355/isijinternational.ISIJINT-2018-068
M3 - Article
AN - SCOPUS:85053490545
VL - 58
SP - 1569
EP - 1577
JO - Transactions of the Iron and Steel Institute of Japan
JF - Transactions of the Iron and Steel Institute of Japan
SN - 0915-1559
IS - 9
ER -