Browsing NTNU Open by Author "M'hamdi, Mohammed"
Now showing items 1-15 of 15
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A simplified three-phase model of equiaxed solidification for the prediction of microstructure and macrosegregation in castings
Tveito, Knut Omdal; Pakanati, Akash; M'hamdi, Mohammed; Combeau, Hervé; Založnik, Miha (Journal article, 2018)Macrosegregation is a result of the interplay of various transport mechanisms, including natural convection, solidification shrinkage, and grain motion. Experimental observations also indicate the impact of grain morphology, ... -
Analysis of the Interplay Between Thermo-solutal Convection and Equiaxed Grain Motion in Relation to Macrosegregation Formation in AA5182 Sheet Ingots
Pakanati, Akash; Tveito, Knut Omdal; M'hamdi, Mohammed; Combeau, Hervé; Založnik, Miha (Peer reviewed; Journal article, 2019)Shrinkage induced flow, thermo-solutal convection and equiaxed grain motion are the major transport mechanisms contributing to macrosegregation formation in aluminum alloys produced through Direct Chill casting. Experimental ... -
Application of an Equiaxed Grain Growth and Transport Model to Study Macrosegregation in a DC Casting Experiment
Pakanati, Akash; Tveito, Knut Omdal; M'hamdi, Mohammed; Combeau, Hervé; Založnik, Miha (Peer reviewed; Journal article, 2019)A simplified three-phase, multiscale macrosegregation model which describes the growth kinetics of equiaxed grains and the coupling between microstructure morphology and the macroscopic transport has been proposed previously. ... -
Assessment of feature engineering and long short-term memory for structure loss identification from process data in monocrystalline silicon growth by the Czochralski method
Sortland, Øyvind Sunde; M'hamdi, Mohammed; Jomâa, Moez (Research report, 2019)Structure loss impairs the quality of monocrystalline ingots and represents a major productivity loss for crystal growers. If structure loss could be predicted in advance it could help reduce the lost production time or ... -
Grain boundary effect on lifetime in high performance multicrystalline silicon during solar cell processing
Adamczyk, Krzysztof; Søndenå, Rune; M'hamdi, Mohammed; Autruffe, Antoine; Stokkan, Gaute; Di Sabatino, Marisa (Journal article; Peer reviewed, 2016)High performance multicrystalline silicon wafers used in solar cell processing have been investigated with focus on quantification of the grain boundary effect on lifetime. The lifetime of a set of 16 wafers from different ... -
High cycle fatigue life estimation of AlSi10Mg processed by laser powder bed fusion
Hovig, Even Wilberg; S. Azar, Amin; Sunding, Martin Fleissner; Sørby, Knut; M'hamdi, Mohammed; Andreassen, Erik (Journal article; Peer reviewed, 2018)Fatigue life is known to be dependent on the surface properties of the material. Surface roughness provokes local stress concentration and cause crack initiation even at minute cyclic loads. In laser powder bed fusion, the ... -
High performance multicrystalline silicon: Grain structure and iron precipitation
Autruffe, Antoine; M'hamdi, Mohammed; Schindler, Florian; Heinz, Friedemann D.; Ekstrøm, Kai Erik; Schubert, Martin C.; Di Sabatino Lundberg, Marisa; Stokkan, Gaute (Journal article; Peer reviewed, 2017)We report results from a national project about impurities in high performance multicrystalline silicon: Contamination sources, transport routes, interaction with crystal defects and impact on solar cell efficiency parameters. ... -
Impact of inlet flow on macrosegregation formation accounting for grain motion and morphology evolution in DC casting of aluminium
Pakanati, Akash; Tveito, Knut Omdal; M'hamdi, Mohammed; Combeau, Hervé; Založnik, Miha (Peer reviewed; Journal article, 2018) -
Impurity control in high performance multicrystalline silicon
Stokkan, Gaute; Di Sabatino Lundberg, Marisa; Søndenå, Rune; Juel, Mari; Autruffe, Antoine; Adamczyk, Krzysztof; Skarstad, Hanna Vaksvik; Ekstrøm, Kai Erik; Wiig, Marie Syre; You, Chang Chuan; Haug, Halvard; M'hamdi, Mohammed (Journal article; Peer reviewed, 2017)We report results from a national project about impurities in high performance multicrystalline silicon: Contamination sources, transport routes, interaction with crystal defects and impact on solar cell efficiency parameters. ... -
Investigation of Macrosegregation Formation in Aluminium DC Casting for Different Alloy Systems
Pakanati, Akash; M'hamdi, Mohammed; Combeau, Hervé; Založnik, Miha (Journal article, 2018)Direct chill (DC) casting of aluminum involves alloys employing different solute elements. In this article, a qualitative analysis and comparison of macrosegregation formation is presented for three different alloy systems: ... -
Investigation of pinholes in Czochralski silicon ingots in relation to structure loss
Sortland, Øyvind Sunde; Øvrelid, Eivind Johannes; M'hamdi, Mohammed; Di Sabatino Lundberg, Marisa (Journal article; Peer reviewed, 2019)In the production of monocrystalline silicon by the Czochralski process, structure loss frequently reduces yield and increases production time. Structure loss means the transition from monocrystalline to multicrystalline ... -
Mechanical Properties of AlSi10Mg Processed by Laser Powder Bed Fusion at Elevated Temperature
Hovig, Even Wilberg; S. Azar, Amin; M'hamdi, Mohammed; Sørby, Knut (Peer reviewed; Journal article, 2020)AlSi10Mg processed by laser powder bed fusion is expected to have remarkable mechanical properties due to the dominant cellular microstructure. However, the as-processed material is often both anisotropic and containing ... -
Semi-solid Constitutive Parameters and Failure Behavior of a Cast AA7050 Alloy
Subroto, Tungky; Eskin, Dmitry G.; Miroux, Alexis; Ellingsen, Kjerstin; M'hamdi, Mohammed; Katgerman, Laurens (Journal article; Peer reviewed, 2021)AA7050 is an aluminum alloy with superior mechanical properties; however, it is prone to hot tearing (HT) during its production via direct-chill casting. This study focuses on extracting constitutive parameters of the alloy ... -
Statistical Analysis of Structure Loss in Czochralski Silicon Growth
Sortland, Øyvind Sunde; Jomâa, Moez; M'hamdi, Mohammed; Øvrelid, Eivind Johannes; Di Sabatino Lundberg, Marisa (Chapter, 2019)In Czochralski monocrystalline silicon growth, structure loss (SL) is the loss of the mono-crystalline structure. It represents a significant loss of productivity. In this work, this phenomenon is investigated by statistical ... -
Statistical analysis of structure loss in Czochralski silicon growth
Sortland, Øyvind Sunde; Jomâa, Moez; M'hamdi, Mohammed; Øvrelid, Eivind Johannes; Di Sabatino Lundberg, Marisa (Journal article; Peer reviewed, 2019)In Czochralski monocrystalline silicon growth, structure loss (SL) is the loss of the mono-crystalline structure. It represents a significant loss of productivity. In this work, this phenomenon is investigated by statistical ...