• Atomic structure of solute clusters in Al-Zn-Mg alloys 

      Lervik, Adrian; Thronsen, Elisabeth; Friis, Jesper; Marioara, Calin Daniel; Wenner, Sigurd; Bendo, Artenis; Matsuda, Kenji; Holmestad, Randi; Andersen, Sigmund Jarle (Peer reviewed; Journal article, 2020)
      Scanning transmission electron microscopy imaging of Al–Zn–Mg alloys has provided new information on the atomic structures of solute rich clusters forming from a supersaturated solid solution at low temperatures. A unique ...
    • Atomic structures of precipitates in Al–Mg–Si alloys with small additions of other elements 

      Saito, Takeshi; Mørtsell, Eva Anne; Wenner, Sigurd; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Friis, Jesper; Matsuda, Kenji; Holmestad, Randi (Peer reviewed; Journal article, 2018)
      In Al–Mg–Si alloys, additions of only a few weight percent of Mg and Si enable formation of hardening precipitates during heat treatment. The precipitation is complex and is influenced by chemical compositions and ...
    • 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 ...
    • The effect of heavy deformation on the precipitation in an Al-1.3Cu-1.0Mg-0.4Si wt.% alloy 

      Thronsen, Elisabeth; Marioara, Calin Daniel; Sunde, Jonas Kristoffer; Minakuchi, Kazuhiro; Katsumi, Tetsuya; Erga, Iven; Andersen, Sigmund Jarle; Friis, Jesper; Marthinsen, Knut; Matsuda, Kenji; Holmestad, Randi (Peer reviewed; Journal article, 2020)
      This work has investigated the effect of the combination of natural ageing and 80% pre-deformation after solution heat treatment on precipitation during subsequent artificial ageing in an Al-1.3Cu-1.0Mg-0.4Si wt.% alloy. ...
    • The Effect of Small Additions of Fe and Heavy Deformation on the Precipitation in an Al–1.1Mg–0.5Cu–0.3Si At. Pct Alloy 

      Thronsen, Elisabeth; Mørkeseth, Hanne; Marioara, Calin Daniel; Minakuchi, Kazuhiro; Katsumi, Tetsuya; Marthinsen, Knut; Matsuda, Kenji; Holmestad, Randi (Peer reviewed; Journal article, 2022)
      The effect of 0.03 and 0.08 at. pct Fe additions on the formation of secondary phases in an Al–1.1Mg–0.5Cu–0.3Si at. pct alloy was investigated. Following solution heat treatment and natural aging, the alloys were analyzed ...
    • 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 ...
    • Probing defects in Al-Mg-Si alloys using muon spin relaxation 

      Wenner, Sigurd; Holmestad, Randi; Matsuda, Kenji; Nishimura, K.; Matsuzaki, T; Tomono, D; Pratt, FL; Marioara, Calin Daniel (Journal article, 2012)
      Muon spin methods are very sensitive to nanoscale defects such as trace elements and vacancies in metals. This sensitivity is required when investigating Al-Mg-Si alloys, a complicated system in which diffusion-controlled ...
    • 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 ...