TY - JOUR
T1 - Mechanical properties of tungsten
T2 - Recent research on modified tungsten materials in Japan
AU - Nogami, Shuhei
AU - Hasegawa, Akira
AU - Fukuda, Makoto
AU - Rieth, Michael
AU - Reiser, Jens
AU - Pintsuk, Gerald
N1 - Funding Information:
Authors are grateful to Prof. K. Yabuuchi of Kyoto university, Prof. T. Miyazawa of Tohoku university, and a lot of students of Prof. A. Hasegawa and Prof. S. Nogami's laboratory of Tohoku University for their contributions to our works. Authors are also grateful to Mr. S. Sickinger, Mr. S. Baumgärtner, Mr. P. Lied, Mr. C. Bonnekoh, Mr. D. Bolich, and Prof. Dr. A. Möslang of Institute for Applied Materials (IAM), Karlsruhe Institute of Technology (KIT) for their support to our Charpy impact tests in KIT. Authors are also grateful to Dr. M. Wirtz, Dr. T. Loewenhoff, and staffs of Institute for Energy and Climate Research (IEK), Forschungszentrum Jülich GmbH (FZJ) for their support to our thermal shock tests in FZJ. Authors are also grateful to Mr. T. Takida and staffs of A.L.M.T. Corp. for their support to our material fabrications. Authors are also grateful to Mr. C. Hisaka, Mr. M. Fujiwara, Mr. T. Kim, Mr. K. Takagi, and staffs of Kobe Material Testing Laboratory Co. Ltd. for their support to our development of fatigue testing machine and fatigue tests of W materials. Authors are also grateful to Mr. S. Fujiwara of Dai-Ichi Kiden Co. Ltd. for his support to our heat treatment and to Mr. Y. Shinoda, Mr. O. Tsukamoto, and Mr. Y. Ishiguro for their support to our thermal conductivity measurements. This work was financially supported by JSPS KAKENHI Grant Number 15KK0224, 26289351, 24246151, 17H01364, and 18H01196. In addition, this work was performed with the support and under the auspices of the National Institute for Fusion Science (NIFS) Collaboration Research program (NIFS11K0BF019).
Funding Information:
This work was financially supported by JSPS KAKENHI Grant Number 15KK0224 , 26289351 , 24246151 , 17H01364 , and 18H01196 . In addition, this work was performed with the support and under the auspices of the National Institute for Fusion Science (NIFS) Collaboration Research program ( NIFS11K0BF019 ).
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/1
Y1 - 2021/1
N2 - There remain some drawbacks of mechanical properties of W materials as a plasma facing material (PFM) for fusion reactor divertors, which are low temperature brittleness, high ductile-to-brittle transition temperature (DBTT), and recrystallization-induced embrittlement. To solve these issues, development of W materials with improved thermo-mechanical properties, neutron irradiation tolerance, and possibility of mass-production with microstructural uniformity has been advanced for the last decade under the collaboration R&D by universities in Japan. In this paper, the effects of grain refining, K-doping, dispersion strengthening by La2O3 particles, and alloying by Re are discussed from the viewpoints of both short- and long-term material properties and phenomena, including effects of neutron irradiation and high heat loads, which should be considered under the actual fusion reactor environments. Through this R&D, K-doping and Re-addition showed several positive effects. Among the materials developed in this R&D, K-doped W-3%Re hot-rolled plate could be a better solution for PFM, which demonstrated superior properties from several perspectives. However, materials alloyed by Re have an intrinsic concern of higher irradiation hardening caused by neutron irradiation up to higher doses. Therefore, it is pointed out that investigations of thermo-mechanical properties under higher dose neutron irradiation are significantly required to realize long-term structural reliability and lifetime of fusion reactors.
AB - There remain some drawbacks of mechanical properties of W materials as a plasma facing material (PFM) for fusion reactor divertors, which are low temperature brittleness, high ductile-to-brittle transition temperature (DBTT), and recrystallization-induced embrittlement. To solve these issues, development of W materials with improved thermo-mechanical properties, neutron irradiation tolerance, and possibility of mass-production with microstructural uniformity has been advanced for the last decade under the collaboration R&D by universities in Japan. In this paper, the effects of grain refining, K-doping, dispersion strengthening by La2O3 particles, and alloying by Re are discussed from the viewpoints of both short- and long-term material properties and phenomena, including effects of neutron irradiation and high heat loads, which should be considered under the actual fusion reactor environments. Through this R&D, K-doping and Re-addition showed several positive effects. Among the materials developed in this R&D, K-doped W-3%Re hot-rolled plate could be a better solution for PFM, which demonstrated superior properties from several perspectives. However, materials alloyed by Re have an intrinsic concern of higher irradiation hardening caused by neutron irradiation up to higher doses. Therefore, it is pointed out that investigations of thermo-mechanical properties under higher dose neutron irradiation are significantly required to realize long-term structural reliability and lifetime of fusion reactors.
KW - Alloying
KW - Dispersion strengthening
KW - Mechanical property
KW - Powder metallurgy
KW - Tungsten
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U2 - 10.1016/j.jnucmat.2020.152506
DO - 10.1016/j.jnucmat.2020.152506
M3 - Article
AN - SCOPUS:85091976243
VL - 543
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
SN - 0022-3115
M1 - 152506
ER -