Blar i NTNU Open på forfatter "Wenner, Sigurd"

Viser treff 41-60 av 74

    • Local mechanical properties and precipitation inhomogeneity in large-grained Al–Mg–Si alloy 

      Hagen, Anette Brocks; Wenner, Sigurd; Bjørge, Ruben; Wan, Di; Marioara, Calin Daniel; Holmestad, Randi; Ringdalen, Inga Gudem (Peer reviewed; Journal article, 2022)
      Al–Mg–Si (6xxx series) alloys show excellent mechanical properties due to the precipitates formed during heat treatment. However, heat treatment of these alloys results in a soft precipitation free zone (PFZ) close to grain ...

    • Mapping the chemistry within, and the strain around, Al-alloy precipitates at atomic resolution by multi-frame scanning transmission electron microscopy 

      Jones, Lewys; Wenner, Sigurd; Nord, Magnus Kristofer; Ninive, Per Harald; Løvvik, Ole Martin; Marioara, Calin Daniel; Holmestad, Randi; Nellist, Peter (Journal article; Peer reviewed, 2017)
      Al-Mg-Si(-Cu)alloys, used primarily in the transportation sector, are strengthened by nano-sized precipitate particles. There is a plethora of possible phases, depending onwhich elements are added to the alloy ...

    • 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 (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 (Journal article; Peer reviewed, 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 ...

    • Nanoscale modelling of combined isotropic and kinematic hardening of 6000 series aluminium alloys 

      Myhr, Ole Runar; Børvik, Tore; Marioara, Calin Daniel; Wenner, Sigurd; Hopperstad, Odd Sture (Peer reviewed; Journal article, 2020)
      Kinematic hardening is incorporated into a nanoscale model for 6000 series aluminium alloys consisting of three sub-models describing in turn precipitation of hardening particles, yield strength and work hardening. The ...

    • On the formation mechanism of Ba0.85Ca0.15Zr0.1Ti0.15O3 thin films by aqueous chemical solution deposition 

      Khomyakova, Evgeniya; Wenner, Sigurd; Bakken, Kristine; Schultheiß, Jan; Grande, Tor; Glaum, Julia; Einarsrud, Mari-Ann (Journal article; Peer reviewed, 2020)
      Here we report on the development of an environmentally friendly, simple and robust aqueous chemical solution route for the fabrication of Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) thin films. Using a stable aqueous precursor solution, ...

    • On the microstructural origins of improvements in conductivity by heavy deformation and ageing of Al-Mg-Si alloy 6101 

      Sunde, Jonas Kristoffer; Marioara, Calin Daniel; Wenner, Sigurd; Holmestad, Randi (Peer reviewed; Journal article, 2021)
      This work has examined an Al-0.54Mg-0.38Si (at.%) conductor alloy (6101) subjected to two different thermomechanical processing routes. Conventional solution treatment, quenching, and artificial ageing (170 °C) was compared ...

    • Optimising multi-frame ADF-STEM for high-precision atomic-resolution strain mapping 

      Jones, Lewys; Wenner, Sigurd; Nord, Magnus Kristofer; Ninive, Per Harald; Løvvik, Ole Martin; Holmestad, Randi; Nellist, P.D. (Journal article; Peer reviewed, 2017)
      Annular dark-field scanning transmission electron microscopy is a powerful tool to study crystal defects at the atomic scale but historically single slow-scanned frames have been plagued by low-frequency scanning-distortions ...

    • Phase stabilization principle and precipitate-host lattice influences for Al-Mg-Si-Cu alloy precipitates 

      Ehlers, Flemming J H; Wenner, Sigurd; Andersen, Sigmund Jarle; Marioara, Calin Daniel; Lefebvre, Williams; Boothroyd, Chris; Holmestad, Randi (Journal article, 2014)
      In this work, we seek to elucidate a common stabilization principle for the metastable and equilibrium phases of the Al–Mg–Si–Cu alloy system, through combined experimental and theoretical studies. We examine the structurally ...

    • Precipitate statistics in an Al-Mg-Si-Cu alloy from scanning precession electron diffraction data 

      Sunde, Jonas Kristoffer; Paulsen, Øyvind; Wenner, Sigurd; Holmestad, Randi (Journal article; Peer reviewed, 2017)
      The key microstructural feature providing strength to age-hardenable Al alloys is nanoscale precipitates. Alloy development requires a reliable statistical assessment of these precipitates, in order to link the microstructure ...

    • Precipitates in aluminium alloys 

      Andersen, Sigmund Jarle; Marioara, Calin Daniel; Friis, Jesper; Wenner, Sigurd; Holmestad, Randi (Journal article; Peer reviewed, 2018)
      Precipitation strengthening is a highly complex phenomenon on the nanoscale, responsible for providing strength in Al-Cu, Al-Mg-Cu, Al-Mg-Zn and Al-Mg-Si alloys. Advances in methodology, especially high-angle annular ...

    • Precipitation behavior in an Al-Cu-Mg-Si alloy during ageing 

      Gazizov, Marat; Marioara, Calin Daniel; Friis, Jesper; Wenner, Sigurd; Holmestad, Randi; Kaibyshev, Rustam (Peer reviewed; Journal article, 2019)
      The precipitation behavior and aging response of an Al-4.9Cu-0.74Mg-0.51Si-0.48Mn-0.1Cr-0.08Ti-0.02Fe (wt. %) alloy was examined in detail after aging at 170 °C with different dwell times up to 96 h. Deformation by ...

    • Precipitation behavior in an Al-Cu-Mg-Si alloy during ageing 

      Gazizov, Marat; Marioara, Calin Daniel; Friis, Jesper; Wenner, Sigurd; Holmestad, Randi; Kaibyshev, Rustam (Peer reviewed; Journal article, 2019)
      The precipitation behavior and aging response of an Al-4.9Cu-0.74Mg-0.51Si-0.48Mn-0.1Cr-0.08Ti-0.02Fe (wt. %) alloy was examined in detail after aging at 170 °C with different dwell times up to 96 h. Deformation by ...

    • Precipitation behavior of Al-Si-Cu-Mg(-Fe) alloys by a deformation-semisolid extrusion process 

      Kim, DaeHan; Kim, JaeHwang; Wenner, Sigurd; Thronsen, Elisabeth; Marioara, Calin Daniel; Holmestad, Randi; Kobayashi, Equo (Journal article; Peer reviewed, 2021)

    • Precipitation behavior of Al-Si-Cu-Mg(-Fe) alloys by a deformation-semisolid extrusion process 

      Kim, DaeHan; Kim, JaeHwang; Wenner, Sigurd; Thronsen, Elisabeth; Marioara, Calin Daniel; Holmestad, Randi; Kobayashi, Equo (Journal article; Peer reviewed, 2021)
      Al-4.5Si-1Cu-0.3Mg(-1Fe) (wt%) alloys fabricated by a deformation-semisolid extrusion (D-SSE) process have been investigated by transmission electron microscopy, down to the atomic level. T5 and T6 heat treatments were ...

    • Precipitation in a mixed Al-Cu-Mg/Al-Zn-Mg alloy system 

      Wenner, Sigurd; Friis, Jesper; Marioara, Calin Daniel; Holmestad, Randi (Journal article, 2016)
      The precipitation-hardened alloy systems Al–Cu–Mg (2xxx) and Al–Zn–Mg (7xxx) were compositionally combined from a base alloy containing 2% Cu and 1% Mg, added 1–4% Zn (weight fractions). Precipitates in these alloys were ...

    • 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; Peer reviewed, 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 ...

    • Progress in Understanding Initiation of Intergranular Corrosion on AA6005 Aluminum Alloy with Low Copper Content 

      Kumari, Shilpa; Wenner, Sigurd; Walmsley, John; Lunder, Otto; Nisancioglu, Kemal (Journal article; Peer reviewed, 2019)
      As part of an extensive research program to study recent, unexpected intergranular corrosion (IGC) on 6xxx series aluminum alloys (AlMgSi), this paper investigates the mechanism of initiation and early propagation of IGC ...

    • Scanning Precession Electron Diffraction Study of 2xxx Series Aluminium Alloys Exhibiting Several Coexisting Strengthening Phases 

      Sunde, Jonas Kristoffer (Master thesis, 2016)
      Throughout this thesis, scanning precession electron diffraction is applied to heat-treated Al-Cu-Li and Al-Mg-Cu-Ag alloys, shedding light on the distribution of phases present and the complex interplay between these ...

    • Scanning Precession Electron Diffraction to aid Aluminum Alloy Development 

      Sunde, Jonas Kristoffer; Christiansen, Emil; Thronsen, Elisabeth; Wenner, Sigurd; Marioara, Calin Daniel; Van Helvoort, Antonius; Holmestad, Randi (Peer reviewed; Journal article, 2019)