Blar i NTNU Open på forfatter "Andersen, Sigmund Jarle"
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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 ... -
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 in an Al-Mg-Cu alloy and the effect of a low amount of Ag
Mihara, Mami; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Holmestad, Randi; Kobayashi, Equo; Sato, Tatsuo (Journal article, 2016)Two high-purity aluminium alloys based on composition Al–3.0Mg–1.0Cu (wt%), one with added 0.4 wt% Ag, were compared up to 11 days ageing at 443 K by means of transmission electron microscopy and hardness measurements. The ... -
Structural investigation of precipitates with Cu and Zn atomic columns in Al-Mg-Si alloys by aberration-corrected HAADF-STEM
Saito, Takeshi; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Lefebvre, Williams; Holmestad, Randi (Journal article; Peer reviewed, 2014)Precipitates in Al-Mg-Si alloys with Cu addition (~0.1 wt%) and Zn addition (~1 wt%) were investigated by aberration corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). Most ... -
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 effect of Cu and Ge additions on strength and precipitation in a lean 6xxx aluminium alloy
Mørtsell, Eva Anne; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Røyset, Jostein; Reiso, Oddvin; Holmestad, Randi (Journal article; Peer reviewed, 2015)It has been demonstrated that the strength loss in a lean Al-Mg-Si alloy due to solute reduction could be compensated by back-adding a lower at % of Ge and Cu. Nanosized precipitate needles which are the main cause of ... -
The Effect of Elastic Strain and Small Plastic Deformation on Tensile Strength of a Lean Al–Mg–Si Alloy
Mørtsell, Eva Anne; Westermann, Ida; Marioara, Calin Daniel; Pedersen, Ketill Olav; Andersen, Sigmund Jarle; Røyset, Jostein; Holmedal, Bjørn; Holmestad, Randi (Journal article; Peer reviewed, 2019)Al–Mg–Si alloys are usually formed into their final shape by rolling or extrusion. After extrusion, the aluminium profiles are usually straightened, causing the material to be subjected to a small plastic deformation. This ... -
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 (Journal article; Peer reviewed, 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 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 ... -
The Effects of Low Cu Additions and Predeformation on the Precipitation in a 6060 Al-Mg-Si Alloy
Saito, Takeshi; Muraishi, Shinji; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Jostein, Røyset; Holmestad, Randi (Journal article, 2013)Effects of low Cu additions (≤0.10 wt pct) and 10 pct predeformation before aging on precipitates’ microstructures and types in a 6060 Al-Mg-Si alloy have been investigated using transmission electron microscopy (TEM). It ... -
The unique hybrid precipitate in a peak-aged Al-Cu-Mg-Ag alloy
Gazizov, Marat; Boev, A.O.; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Holmestad, Randi; Kaibyshev, Rustam; Aksyonov, D.A.; Krasnikov, V.S. (Peer reviewed; Journal article, 2021)The prevalent hardening phase forming in an Al-Cu-Mg-Ag alloy after peak-aging at 150 and 190 °C has been investigated using transmission electron microscopy methods. The precipitate atomic structure was determined. It is ...