Blar i SINTEF Open på forfatter "Nishimura, Katsuhiko"
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Characterisation of structural similarities of precipitates in Mg–Zn and Al–Zn–Mg alloys systems
Bendo, Artenis; Maeda, Tomoyoshi; Matsuda, Kenji; Lervik, Adrian; Holmestad, Randi; Marioara, Calin Daniel; Nishimura, Katsuhiko; Nunomura, Norio; Toda, Hiroyuki; Yamaguchi, Masatake; Ikeda, Ken-ichi; Homma, Tomoyuki (Peer reviewed; Journal article, 2019)High angle annular dark field scanning transmission electron microscopy has been employed to observe precipitate structures in Al–Zn–Mg and Mg–Zn alloys. h1 precipitate structures in Al–Zn–Mg are commonly formed by MgZn2 ... -
Clustering and Vacancy Behavior in High- and Low-Solute Al-Mg-Si Alloys
Wenner, Sigurd; Nishimura, Katsuhiko; Matsuda, Kenji; Matsuzaki, Teiichiro; Tomono, Dai; Pratt, Francis L.; Marioara, Calin Daniel; Holmestad, Randi (Journal article; Peer reviewed, 2014)The precipitate microstructure and vacancy distribution in Al-Mg-Si alloys with different amounts of solute and different heat treatments were investigated by transmission electron microscopy and muon spin relaxation ... -
Effect of copper addition on the cluster formation behavior of Al-Mg-Si, Al-Zn-Mg, and Al-Mg-Ge in the natural aging
Hatakeyama, Daichi; Nishimura, Katsuhiko; Matsuda, Kenji; Namiki, Takahiro; Lee, Seungwon; Nunomura, Norio; Aida, Tetsuo; Matsuzaki, Teiichiro; Holmestad, Randi; Wenner, Sigurd; Marioara, Calin Daniel (Peer reviewed; Journal article, 2018)The time-dependent resistivity of Al-Mg-Si(-Cu), Al-Zn-Mg(-Cu), and Al-Mg-Ge(-Cu) alloys are studied over a range of constant temperatures between 255 K and 320 K. The resistivity vs time curves for the samples show three ... -
Muon kinetics in heat treated Al (–Mg)(–Si) alloys
Wenner, Sigurd; Nishimura, Katsuhiko; Matsuda, Kenji; Matsuzaki, Teiichiro; Tomono, Dai; Pratt, Francis L.; Marioara, Calin Daniel; Holmestad, Randi (Peer reviewed; Journal article, 2013)Al–Mg–Si alloys are heat-treatable and rely on precipitation hardening for their mechanical strength. We have employed the technique of muon spin relaxation to further our understanding of the complex precipitation sequence ... -
Muon Spin Relaxation Study of Solute–Vacancy Interactions During Natural Aging of Al-Mg-Si-Cu Alloys
Wenner, Sigurd; Marioara, Calin Daniel; Nishimura, Katsuhiko; Matsuda, Kenji; Lee, Seungwon; Namiki, Takahiro; Watanabe, Isao; Matsuzaki, Teiichiro; Holmestad, Randi (Peer reviewed; Journal article, 2019)Muon spin relaxation has the unique ability to detect very low concentrations of vacancies and vacancy–solute complexes in solids. In this work, we investigate quaternary Al-Mg-Si-Cu alloys and show that after quenching ... -
µSR study of Al-0.67%Mg-0.77%Si alloys
Nishimura, Katsuhiko; Matsuda, Kenji; Komaki, R; Nunomura, Norio; Wenner, Sigurd; Holmestad, Randi; Matsuzaki, Teiichiro; Watanabe, Isao; Pratt, Francis L.; Marioara, Calin Daniel (Peer reviewed; Journal article, 2014)Zero-field muon spin relaxation measurements were carried out with Al-0.67%Mg- 0.77%Si alloys in the temperature range from 20 K to 300 K. Observed relaxation spectra were compared with the relaxation functions calculated ...