Blar i SINTEF Open på forfatter "Wenner, Sigurd"
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Effects of Water Content and Temperature on Bulk Resistivity of Hybrid Cement/Carbon Nanofiber Composites
Gawel, Kamila; Taghipour, Ali; Bjørge, Ruben; Wenner, Sigurd; Gawel, Bartlomiej; Ghaderi, Amir; Cerasi, Pierre (Peer reviewed; Journal article, 2020)Cement nanocomposites with carbon nanofibers (CNFs) are electrically conductive and sensitive to mechanical loads. These features make them useful for sensing applications. The conductive and load sensing properties are ... -
Electrochemical enhancement and inhibition of calcium carbonate deposition
Edvardsen, Laura; Gawel, Kamila; Wenner, Sigurd; Gawel, Bartlomiej; Torsæter, Malin (Peer reviewed; Journal article, 2020)Calcium carbonate is by far the most widespread scaling material. Its deposition in pipes and flowlines has been a long-standing problem for many industries. Hence, a lot of research is devoted to scale inhibition. One of ... -
Electrochemically Enhanced Deposition of Minerals from Synthetic Reservoir Brine
Edvardsen, Laura; Emmel, Benjamin Udo; Bhuiyan, Mohammad Hossain; Wenner, Sigurd; Gawel, Kamila; Torsæter, Malin (SINTEF Proceedings;7, Chapter; Peer reviewed; Conference object, 2021)In this paper we ask the question whether or not electrochemically enhanced deposition of minerals can be utilized to repair leakage paths existing in cement plugs in wells. Electrical polarization of two electrodes may ... -
Elemental electron energy loss mapping of a precipitate in a multi-component aluminium alloy
Mørtsell, Eva Anne; Wenner, Sigurd; Longo, Paulo; Andersen, Sigmund Jarle; Marioara, Calin Daniel; Holmestad, Randi (Peer reviewed; Journal article, 2016)The elemental distribution of a precipitate cross section, situated in a lean Al-Mg-Si-Cu-Ag-Ge alloy, has been investigated in detail by electron energy loss spectroscopy (EELS) and aberration corrected high angle annular ... -
Filler metal distribution and processing stability in laser-arc hybrid welding of thick HSLA steel
Bunaziv, Ivan; Wenner, Sigurd; Ren, Xiaobo; Frostevarg, Jan; Kaplan, Alexander F.H.; Akselsen, Odd Magne (Peer reviewed; Journal article, 2020)Welds made by high power laser beam have deep and narrow geometry. Addition offiller wire by the arc source,forming the laser-arc hybrid welding (LAHW) process, is very important to obtain required mechanical prop-erties. ... -
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 ... -
Grain boundary structures and their correlation with intergranular corrosion in an extruded Al-Mg-Si-Cu alloy
Lervik, Adrian; Wenner, Sigurd; Lunder, Otto; Marioara, Calin Daniel; Holmestad, Randi (Peer reviewed; Journal article, 2020)A detailed analysis of grain boundaries in a highly textured Al-Mg-Si-Cu alloy is presented in this work. Electron backscatter diffraction demonstrates the presence of three main categories of grain boundaries in addition ... -
How calcium prevents precipitation hardening in Al–Mg–Si alloys
Wenner, Sigurd; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Holmestad, Randi (Peer reviewed; Journal article, 2013)We have investigated the effect on precipitate microstructure and hardness upon adding small amounts of Ca to a base Al–Mg–Si alloy. The main investigative techniques were transmission and scanning electron microscopy. We ... -
A hybrid aluminium alloy and its zoo of interacting nano-precipitates
Wenner, Sigurd; Marioara, Calin Daniel; Andersen, Sigmund Jarle; Ervik, Martin; Holmestad, Randi (Peer reviewed; Journal article, 2015)An alloy with aluminium as its base element is heat treated to form a multitude of precipitate phases known from different classes of industrial alloys: Al–Cu(–Mg), Al–Mg–Si–Cu, and Al–Zn–Mg. Nanometer-sized needle-shaped ... -
In situ heating TEM observations of evolving nanoscale Al‐Mg‐Si‐Cu precipitates
Sunde, Jonas Kristoffer; Wenner, Sigurd; Holmestad, Randi (Peer reviewed; Journal article, 2019)This research concerns the precipitation and subsequent dissolution of precipitate phases in an Al–0.86Mg–0.62Si–0.1Cu (at.%) alloy subjected to varying thermal exposure during an in situ heating transmission electron ... -
Limitations of Ultrathin Al2O3 Coatings on LNMO Cathodes
Østli, Elise Ramleth; Tesfamhret, Yonas; Wenner, Sigurd; Lacey, Matthew J.; Brandell, Daniel; Svensson, Ann Mari; Selbach, Sverre Magnus; Wagner, Nils P. (Peer reviewed; Journal article, 2021)This study demonstrates the application of Al2O3 coatings for the high-voltage cathode material LiNi0.5–xMn1.5+xO4−δ (LNMO) by atomic layer deposition. The ultrathin and uniform coatings (0.6–1.7 nm) were deposited on LNMO ... -
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 (Peer reviewed; Journal article, 2017) -
MgH2–CoO: a conversion-type composite electrode for LiBH4-based all-solid-state lithium ion batteries
El-Kharbachi, Abdelouahab; Uesato, Hiroki; Kawai, Hironori; Wenner, Sigurd; Miyaoka, Hiroki; Sørby, Magnus Helgerud; Fjellvåg, Helmer; Ichikawa, Takayuki; Hauback, Bjørn (Journal article; Peer reviewed, 2018)Several studies have demonstrated that MgH2 is a promising conversion-type anode toward Li. A major obstacle is the reversible capacity during cycling. Electrochemical co-existence of a mixed metal hydride-oxide conversion ... -
Monitoring of Co2 Well Plug Integrity. Electrical Response of Cement/CNF Sensor to Mechanical Load, Water Saturation and Carbonation
Gawel, Kamila; Wenner, Sigurd; Taghipour, Ali; Szewczyk, Dawid; Edvardsen, Laura; Brocks, Anette; Hagen, Anna Stroisz; Gawel, Bartlomiej; Bjørge, Ruben; Ghaderi, Amir; Cerasi, Pierre; Malin, Torsæter (SINTEF Proceedings;7, Chapter; Peer reviewed; Conference object, 2021)CO2 storage wells will eventually need to be permanently plugged and abandoned. Subsidence, fault/fracture reactivation or chemical degradation can all adversely affect well plug integrity leading to CO2 leakages. Thus, ... -
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 (Peer reviewed; 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 (Peer reviewed; Journal article, 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 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 ... -
Portland cement hydration in the vicinity of electrically polarized conductive surfaces
Gawel, Kamila; Wenner, Sigurd; Jafariesfad, Narjes; Torsæter, Malin; Justnes, Harald (Peer reviewed; Journal article, 2022)Hardening of Portland cement-based materials in vicinity of electrically conductive surfaces, especially when the surfaces are electrically or galvanically polarized, can lead to both morphological and chemical changes in ...