Browsing NTNU Open by Author "Ringdalen, Inga Gudem"

Now showing items 1-18 of 18

    • Atomistic approach to simulate kink migration and kink-pair formation in silicon: The kinetic activation-relaxation technique 

      Eliassen, Simen Nut Hansen; Friis, Jesper; Ringdalen, Inga Gudem; Mousseau, Normand; Trochet, Mickaël; Li, Yanjun (Journal article; Peer reviewed, 2019)
      The energy conversion efficiency of solar cells based on multicrystalline silicon is greatly deteriorated by dislocations. However, an in-depth understanding on the dislocation motion dynamics down to atomic scale is still ...

    • Atomistic Scale Modelling of Defects in Aluminium Alloys 

      Frafjord, Jonas (Doctoral theses at NTNU;2020:400, Doctoral thesis, 2020)
      «Deformasjoner som en ser når metall bøyer seg, er en kollektiv bevegelse av små linjedefekter i atomstrukturen.» Dette sitatet oppsummerer temaet til doktorgradsarbeidet som handler om hvordan atomer i aluminium oppfører ...

    • Deformation and strain localization in polycrystals with plastically heterogeneous grains 

      Khadyko, Mikhail; Marioara, Calin Daniel; Ringdalen, Inga Gudem; Dumoulin, Stephane; Hopperstad, Odd Sture (Journal article; Peer reviewed, 2016)
      A model of a polycrystalline material is studied, where each grain consists of several zones with different plastic properties. The size and configuration of the zones as well as their properties are mimicking the situation ...

    • Detailed investigation of the shearing mechanism of β" precipitates in Al-Mg-Si alloys 

      Christiansen, Emil; Marioara, Calin Daniel; Ringdalen, Inga Gudem; Bjørge, Ruben; Holmedal, Bjørn; Hopperstad, Odd Sture; Holmestad, Randi (Peer reviewed; Journal article, 2020)
      The mechanism behind shearing of β'' precipitates in Al-Mg-Si alloys during deformation is investigated by applying advanced transmission electron microscopy (TEM) techniques and frozen phonon multislice TEM image simulations ...

    • Directionality and column arrangement principles of precipitates in Al-Mg-Si-(Cu) and Al-Mg-Cu linked to line defect in Al 

      Andersen, Sigmund Jarle; Marioara, Calin Daniel; Friis, Jesper; Bjørge, Ruben; Du, Qiang; Ringdalen, Inga Gudem; Wenner, Sigurd; Mørtsell, Eva Anne; Holmestad, Randi; Saito, Takeshi; Røyset, Jostein; Reiso, Oddvin (Journal article, 2016)
      In the structures of all metastable precipitates in Al-Mg-Cu and Al-Mg-Si alloys, we find that column surrounding of an element column in the needle/lath direction order according to simple principles. Advanced transmission ...

    • Dislocation dynamics study of precipitate hardening in Al-Mg-Si alloys with input from experimental characterization 

      Ringdalen, Inga Gudem; Wenner, Sigurd; Friis, Jesper; Marian, Jaime (Journal article; Peer reviewed, 2017)
      Partial aging of AA6060 aluminum alloys is known to result in a microstructure characterized by needle-shaped Si/Mg-rich precipitates. These precipitates belong to the non-equilibrium β″ phase and are coherent with the ...

    • Ductile mechanisms of metals containing pre-existing nanovoids 

      Zhao, Kai; Ringdalen, Inga Gudem; Wu, Jianyang; He, Jianying; Zhang, Zhiliang (Journal article; Peer reviewed, 2016)
      The void growth in monocrystalline Cu and Fe are investigated by molecular dynamics simulations to reveal the ductile mechanisms based on dislocation emission and propagation. The results show that the void growth in Cu ...

    • Effect of amorphization-mediated plasticity on the hydrogen-void interaction in ideal lattices under hydrostatic tension 

      Zhao, Kai; He, Jianying; Ringdalen, Inga Gudem; Zhang, Zhiliang (Journal article; Peer reviewed, 2018)
      A thermodynamic model is derived to study the void nucleation in ideal lattices under hydrostatic tension loading and predicts that the plasticity has to be initiated before homogeneous nucleation of voids. Molecular ...

    • First principle calculations of pressure dependent yielding in solute strengthened aluminium alloys 

      Frafjord, Jonas; Ringdalen, Inga Gudem; Hopperstad, Odd Sture; Holmestad, Randi; Friis, Jesper (Journal article; Peer reviewed, 2020)
      The pressure dependence of the yield stress in solute strengthened aluminium alloys is investigated by first principle calculations. The solute elements studied are magnesium, silicon and copper. A fixed boundary cluster ...

    • First-principles study of tensile and shear strength of an Fe2Al5//Fe interface 

      Khalid, Muhammad Zeeshan; Friis, Jesper; Ninive, Per Harald; Marthinsen, Knut; Ringdalen, Inga Gudem; Strandlie, Are (Peer reviewed; Journal article, 2021)
      The interfacial strengths of a low misfit Fe2Al5//Fe interface structure found at aluminum-steel joints has been studied using density functional theory. An interface between Fe and Fe2Al5 was selected based on a criteria ...

    • Fully resolved strain field of the β’’ precipitate calculated by density functional theory 

      Frafjord, Jonas; Dumoulin, Stephane; Wenner, Sigurd; Ringdalen, Inga Gudem; Holmestad, Randi; Friis, Jesper (Peer reviewed; Journal article, 2020)
      The β′′ precipitate is the main hardening phase in age hardenable Al-Mg-Si alloys, and it is therefore of major scientific and industrial importance. A full model of the β′′ precipitate cross-section embedded in an aluminium ...

    • 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 ...

    • Modified embedded atom method potential for Fe-Al intermetallics mechanical strength: A comparative analysis of atomistic simulations 

      Khalid, Muhammad Zeeshan; Friis, Jesper; Ninive, Per Harald; Marthinsen, Knut; Ringdalen, Inga Gudem; Strandlie, Are (Peer reviewed; Journal article, 2021)
      The structural and mechanical properties of Fe-Al compounds (FeAl, FeAl, FeAl, FeAl, FeAl, FeAl) have been studied using modified embedded atom method (MEAM) potentials. The equilibrium lattice constants, formation enthalpies, ...

    • Multislice image simulations of sheared needle‐like precipitates in an Al‐Mg‐Si alloy 

      Christiansen, Emil; Ringdalen, Inga Gudem; Bjørge, Ruben; Marioara, Calin Daniel; Holmestad, Randi (Peer reviewed; Journal article, 2020)
      The image contrast of sheared needle‐like urn:x-wiley:00222720:media:jmi12901:jmi12901-math-0001 precipitates in the Al‐Mg‐Si alloy system is investigated with respect to shear‐plane positions, the number of shear‐planes, ...

    • On intermetallic phases formed during interdiffusion between aluminium alloys and stainless steel 

      Bergh, Tina; Arbo, Siri Marthe; Hagen, Anette Brocks; Blindheim, Jørgen; Friis, Jesper; Khalid, Muhammad Zeeshan; Ringdalen, Inga Gudem; Holmestad, Randi; Westermann, Ida; Vullum, Per Erik (Peer reviewed; Journal article, 2022)
      One of the major challenges in welding of aluminium (Al) alloys and steels is the growth of brittle intermetallic phases, which depends on the thermomechanical processing history and the alloying elements. This work focuses ...

    • On the Atomic Structure of the β′′ Precipitate by Density Functional Theory 

      Frafjord, Jonas; Ringdalen, Inga Gudem; Holmestad, Randi; Friis, Jesper (Peer reviewed; Journal article, 2023)
      The substitution of elements into the precipitate in the 6xxx-series of aluminium alloys is an interface sensitive problem. The strain caused by the misfit between the precipitate and the matrix interacts with the size ...

    • 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 ...

    • α-Mg primary phase formation and dendritic morphology transition in solidification of a Mg-Nd-Gd-Zn-Zr casting alloy 

      Casari, Daniele; Mirihanage, Wajira; Falch, Ken Vidar; Ringdalen, Inga Gudem; Friis, Jesper; Schmid-Fetzer, Rainer; Zhao, Dongdong; Li, Yanjun; Sillekens, Wim H.; Mathiesen, Ragnvald (Journal article; Peer reviewed, 2016)
      Microstructure evolution in the commercial Mg-Nd-Gd-Zn-Zr alloy Elektron 21, solidified under nearly isothermal conditions, has been studied via in-situ X-ray radiography. For cooling rates View the MathML source≤0.075 ...