Browsing Institutt for fysikk by Author "Saito, Takeshi"
Now showing items 1-12 of 12
-
Aberration-corrected HAADF-STEM investigations of precipitate structures in Al-Mg-Si alloys with low Cu additions
Saito, Takeshi; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Lefebvre, Williams; Holmestad, Randi (Journal article, 2014)Precipitates in a lean Al–Mg–Si alloy with low Cu addition (~0.10 wt.%) were investigated by aberration-corrected high angle annular dark field scanning transmission electron microscopy (HAADF-STEM). Most precipitates were ... -
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 ... -
Cu atoms suppress misfit dislocations at the β″/Al interface in Al-Mg-Si alloys
Saito, Takeshi; Ehlers, Flemming J H; Lefebvre, Williams; Hernandez-Maldonado, David; Bjørge, Ruben; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Mørtsell, Eva Anne; Holmestad, Randi (Journal article, 2016)The Cu interactions with the Al–Mg–Si alloy main hardening phase β″ are investigated in atomic scale, by using experimental and simulated high angle annular dark-field scanning transmission electron microscopy techniques ... -
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 ... -
Effect of low Cu addition and thermo-mechanical history on precipitation in Al-Mg-Si alloys
Saito, Takeshi; Marioara, Calin Daniel; Røyset, Jostein; Holmestad, Randi (Journal article, 2014)The effect of cooling rate after solution heat treatment and its combination with 1% pre-deformation on precipitation hardening in two Al-Mg-Si alloys is investigated by transmission electron microscopy (TEM), and related ... -
HAADF-STEM and DFT investigations of the Zn-containing β'' phase in Al-Mg-Si alloys
Saito, Takeshi; Ehlers, Flemming J H; Lefebvre, Williams; Hernandez-Maldonado, D; Bjørge, Ruben; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Holmestad, Randi (Journal article, 2014)The Zn-containing β″ phase in Al–Mg–Si alloys was investigated by aberration corrected high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), combined with density functional theory (DFT) ... -
Influence of low Cu addition on quench sensitivity in Al-Mg-Si alloys
Saito, Takeshi; Marioara, Calin Daniel; Røyset, Jostein; Holmestad, Randi (Journal article, 2014)Quench sensitivity in two Al-Mg-Si alloys, one Cu-free and the other with low Cu additions (~0.1 wt%), both having the same amounts of other solutes, has been investigated using transmission electron microscopy (TEM) and ... -
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 ... -
The Effect of Trace Elements on Precipitation in Al-Mg-Si alloys - A Transmission Electron Microscopy Study
Saito, Takeshi (Doktoravhandlinger ved NTNU, 1503-8181; 2014:171, Doctoral thesis, 2014)Atomic scale studies of aluminum alloys The thesis focuses on structural analysis of particles (precipitates) in the important aluminum alloys – Al-Mg-Si alloys, studied by transmission electron microscopy (TEM) including ... -
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 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 effects of quench rate and pre-deformation on precipitation hardening in Al–Mg–Si alloys with different Cu amounts
Saito, Takeshi; Marioara, Calin Daniel; Røyset, Jostein; Marthinsen, Knut; Holmestad, Randi (Journal article, 2014)The effects of quench rate after solution heat treatment in combination with 1% pre-deformation on precipitation hardening in three Al–Mg–Si alloys have been investigated by transmission electron microscopy and hardness ...