Blar i NTNU Open på forfatter "Wenner, Sigurd"

Viser treff 61-74 av 74

    • Selective area grown ZnTe nanowires as the basis for quasi-one-dimensional CdTe-HgTe multishell heterostructures 

      Hajer, Jan; Mantei, Willi; Kessel, Maximilian; Brüne, Christoph; Wenner, Sigurd; Van Helvoort, Antonius; Buhmann, Hartmut; Molenkamp, Laurens W. (Peer reviewed; Journal article, 2020)
      Selective area growth is employed in the vapor-liquid-solid molecular beam epitaxy of ZnTe nanowire arrays. Full control over the location of the individual nanowires is achieved by defined positioning of the growth catalyst. ...

    • Solute-vacancy clustering in Al-Mg-Si alloys studied by muon spin relaxation technique 

      Nishimura, Katsuhiko; Matsuda, Kenji; Komaki, R.; Nunomra, Norio; Wenner, Sigurd; Holmestad, Randi; Matsuzaki, Teiichiro; Watanabe, Isao; Pratt, Francis Laurence (Journal article; Peer reviewed, 2015)
      Zero-field muon spin relaxation experiments were carried out with Al-1.6%Mg2Si, Al-0.5%Mg, and Al-0.5%Si alloys. Observed relaxation spectra were compared with the calculated relaxation functions based on the Monte Carlo ...

    • Strengthening mechanisms in ultrafine grained Al-Mg-Si alloy processed by hydrostatic extrusion – Influence of ageing temperature 

      Chrominski, Witold; Wenner, Sigurd; Marioara, Calin Daniel; Holmestad, Randi; Lewandowska, Malgorzata (Journal article, 2016)
      Microstructure of hydrostatically extruded Al-Mg-Si alloy was studied by the combination of electron backscattered diffraction and transmission electron microscopy. Three different grain types which feature various defects ...

    • Structural Characterization of Natural Quartz by Scanning TEM 

      Busam, Jochen; Wenner, Sigurd; Muggerud, Astrid Marie; Van Helvoort, Antonius (Journal article; Peer reviewed, 2018)
      For quartz, despite its industrial importance and an extensive amount of research done on it, there are still open fundamental questions, e.g. regarding crystal defects, phase changes or damage mechanisms under ionizing ...

    • Structural modifications and electron beam damage in aluminium alloy precipitate θ'-Al2Cu 

      Wenner, Sigurd; Friis, Jesper; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Holmestad, Randi (Journal article, 2015)
      The –AlCu phase in an Al–4Zn–2Cu–1Mg–0.7Si (wt.%) alloy was investigated by means of scanning transmission electron microscopy. With our specific alloy composition, the phase is often formed with stacking faults on and ...

    • Studying GPI zones in Al-Zn-Mg alloys by 4D-STEM 

      Thronsen, Elisabeth; Frafjord, Jonas; Friis, Jesper; Marioara, Calin Daniel; Wenner, Sigurd; Andersen, Sigmund Jarle; Holmestad, Randi (Journal article; Peer reviewed, 2021)
      A new methodology has been developed to study the fine details of GP zones in age-hardenable aluminium alloys. It is complementary to atomic resolution high-angle annular dark-field scanning transmission electron microscopy ...

    • The correlation between intergranular corrosion resistance and copper content in the precipitate microstructure in an AA6005A alloy 

      Marioara, Calin Daniel; Lervik, Adrian; Grønvold, Julie; Lunder, Otto; Wenner, Sigurd; Furu, Trond; Holmestad, Randi (Journal article; Peer reviewed, 2018)
      A positive correlation is observed between the amount of Cu incorporated in hardening precipitates and intergranular corrosion resistance in an artificially aged Cu-containing 6005A alloy. Three mechanisms have been ...

    • The Effect of Zn on precipitation in Al-Mg-Si alloys 

      Saito, Takeshi; Wenner, Sigurd; Osmundsen, Elisa; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Røyset, Jostein; Lefebvre, Williams; Holmestad, Randi (Journal article, 2014)
      Effects of addition of Zn (up to 1 wt%) on microstructure, precipitate structure and intergranular corrosion (IGC) in an Al–Mg–Si alloys were investigated. During ageing at 185 °C, the alloys showed modest increases in ...

    • The effects and behaviour of Li and Cu alloying agents in lean Al-Mg-Si alloys 

      Mørtsell, Eva Anne; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Ringdalen, Inga Gudem; Friis, Jesper; Wenner, Sigurd; Røyset, Jostein; Reiso, Oddvin; Holmestad, Randi (Journal article, 2016)
      We show how replacing a fraction of Mg with Li in a lean Al-Mg-Si alloy gives comparable strength and enhanced temperature stability. Replacing solute with smaller amounts of Cu and Li also improves thermal stability and ...

    • Thermal stability of the lightweight 2099 Al-Cu-Li alloy: Tensile tests and microstructural investigations after overaging 

      Balducci, E; Ceschini, L; Messieri, S; Wenner, Sigurd; Holmestad, Randi (Journal article, 2017)
      The thermal stability of the lightweight, T83 heat treated 2099 Al-Cu-Li alloy was assessed in the temperature range 200–305 °C, through both hardness and tensile tests after overaging. After prolonged thermal exposure, ...

    • Transmission electron microscopy and muon spin relaxation studies of precipitation in Al–Mg–Si alloys 

      Wenner, Sigurd (Doktoravhandlinger ved NTNU, 1503-8181; 2014:1, Doctoral thesis, 2014)
      The Al–Mg–Si system is a heat-treatable class of aluminium alloys that gain their mechanical strength via precipitation hardening. The main hardening phases are precipitated as needle-shaped nano-sized particles from a ...

    • Transmission electron microscopy based characterization of CdTe–HgTe core–shell semiconductor nanowires 

      Bakke, Ragna (Master thesis, 2020)
      Denne avhandlingen rapporterer resultatene fra tøyningskartlegging på heterostrukturerte CdTe–HgTe kjerne–skallnanotråder, tiltenkt å fungere som kvasiendimensjonale topologiske isolatorer. Tøyningskartlegging har blitt ...

    • Transmission Electron Microscopy Study of Two Peak Hardened Al-Mg-Si-Cu Alloys 

      Paulsen, Øyvind (Master thesis, 2017)
      In this thesis, a variety of techniques within the field of transmission electron microscopy have been applied in the study of two dense 6xxx series aluminium alloys, at their peak hardness. This is a class of age-hardenable ...

    • 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 (Journal article; Peer reviewed, 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 ...