Browsing NTNU Open by Author "Friis, Jesper"
Now showing items 1-20 of 37
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A First-Principles Study of the Al (001)/Fe(0-11) Interface
Khalid, Muhammad Zeeshan; Friis, Jesper; Ninive, Per Harald; Marthinsen, Knut; Strandlie, Are (Journal article; Peer reviewed, 2018)Two phase Stefan problem was solved using analytical method in cylindrical domain. To solve governing equations Eigen conditions were formulated by using separation of variable technique. Eigenvalues of the eigencondition ... -
Ab-initio study of atomic structure and mechanical behaviour of Al / Fe intermetallic interfaces
Khalid, Muhammad Zeeshan; Friis, Jesper; Ninive, Per Harald; Marthinsen, Knut; Strandlie, Are (Journal article; Peer reviewed, 2020)First-principles virtual tensile and shear test calculations have been performed to Al(0 0 )//-AlFeSi(0 0 1) and Al(0 4)//Fe4Al13(1 0 ) interfaces by the ab initio pseudo potential density functional theory method. Work ... -
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 (Journal article; Peer reviewed, 2021)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 (Journal article; Peer reviewed, 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 ... -
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 details of precipitates in lean Al–Mg–Si alloys with trace additions of Ag and Ge studied by HAADF-STEM and DFT
Mørtsell, Eva Anne; Andersen, Sigmund Jarle; Friis, Jesper; Marioara, Calin Daniel; Holmestad, Randi (Journal article, 2017)Bonding energies and volume misfits for alloying elements and vacancies in multicomponent Al–Mg–Si alloys have been calculated using density functional theory (DFT). A detailed atomic scale analysis has been done for ... -
Atomistic modelling of Fe-Al and α-AlFeSi intermetallic compound interfaces
Khalid, Muhammad Zeeshan (Doctoral theses at NTNU;2020:86, Doctoral thesis, 2020)The joining of aluminum and steel has been considered an efficient solution for building light-weight technology, particularly in the automotive, aerospace and shipbuilding industries. It is an immense challenge to join ... -
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 ... -
Characterization and Modelling of the Microstructure and Texture Evolution In AlMgSi-Extrusions
Zhang, Kai; Marthinsen, Knut; Holmedal, Bjørn; Friis, Jesper; Pettersen, Tanja; Segatori, Antonio (Journal article, 2017)The properties and surface appearance of aluminium extrusion are critically dependent on the microstructure and texture of the extruded profiles, and the requirements with respect to these aspects may vary with applications. ... -
Data on atomic structures of precipitates in an Al-Mg-Cu alloy studied by high resolution transmission electron microscopy and first-principles calculations
Chen, Xuanliang; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Friis, Jesper; Lervik, Adrian; Holmestad, Randi; Kobayashi, Equo (Journal article; Peer reviewed, 2021)The dataset refers to the research article “Precipitation processes and structural evolutions of various GPB zones and two types of S phases in a cold-rolled Al-Mg-Cu alloy” [1]. Transmission electron microscopy (TEM) and ... -
Density Functional Theory Studies of Precipitate Interfaces in Aluminium Alloys, with Focus on Theta'-Al2Cu
Østli, Philip (Master thesis, 2016)The atomic structure of bulk crystal of aluminium and the precipitate phase $\theta^\prime$ connected to age-hardening of Al-Cu alloys have been studied using Density Functional Theory (DFT). The lattice constant of ... -
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 ... -
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 ... -
First-principles study of tensile and shear strength of Fe-Al and α-AlFeSi intermetallic compound interfaces
Khalid, Muhammad Zeeshan; Friis, Jesper; Ninive, Per Harald; Marthinsen, Knut; Strandlie, Are (Peer reviewed; Journal article, 2021)First-principles virtual tensile and shear strength calculations have been performed on the Fe2Al5// Fe4Al13 and -AlFeSi// Fe4Al13 interfaces. The Fast Inertial Relaxation Engine (FIRE) algorithm is used for optimizing ... -
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 ... -
Implementation and Testing of Numerical Models for Evolution of Microchemistry and Microstructure During Back-Annealing of Aluminium Alloys
Iversen, Jørgen Tandberg (Master thesis, 2014)Precipal and Alsoft are two separate models for simulating the effects of back-annealing on microchemistry and microstructure, respectively, in AA3xxx-type aluminium alloys (i.e Mn containing alloys). The precipitation ... -
Kinetic Monte Carlo simulation of the early precipitation stages in Al-Mg-Si alloys using Cluster Expansion methods for energy barrier modelling
Haltbakk, Marthe Strand (Master thesis, 2021)I denne masteroppgaven er Al-Mg-Si legeringer undersøkt ved hjelp av kinet- isk Monte Carlo simulasjoner styrt av energibarrierer. Arbeidet er en fortset- telse av tidligere arbeid som modellerte barrierene ved hjelp av ... -
Kinetic Monte Carlo simulations of the early stages of precipitation in Al-Mg-Si alloys using ab initio based activation energies
Nygård, Øystein Tormodsen (Master thesis, 2020)Kinetisk Monte Carlo simuleringer har blitt utført med bruk av to ulike uttrykk for aktiveringsenergiene med hensikt til å få bedre innsikt i kinetikken i den tidlige fasen av presipitering i Al-Mg-Si legeringer på atomnivå. ...