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Visar resultat 1 - 5 av 9 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Functional Metallic Glasses

   Författare :Ansar Masood; Lyubov Belova; K. Venkat Rao; Lars Arnberg; KTH; []
   Nyckelord :Bulk Metallic glasses; glass forming ability; soft magnetism; thin films; magnetic properties; magnetic hardening; plasticity; biocompatibility;

   Sammanfattning : For decades, Metallic Glass, with its isotropic featureless structure while exhibiting outstanding mechanical properties was possible only at a high rate of quenching and with at least one dimension in the submicron regime.  This limitation was overcome with the discovery of Bulk Metallic glasses, BMGs, containing three or more elements following the additional two empirical rules of optimum geometric size differences and negative energy of mixing among the constituent elements. LÄS MER

3. 2. Local structure and composition : in additively manufactured bulk metallic glasses and composites

   Författare :Inga Katharina Goetz; Jochen M. Schneider; Björgvin Hjörvarsson; Ulf Jansson; Maria Teresa Pérez Prado; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; additive manufacturing; bulk metallic glasses; nanoscale clustering; convective flow; laser nitriding; laser powder bed fusion; metallic glass - ceramic composites; oxygen impurities; mechanical properties; magnetic properties; viscosity; Fysik; Physics;

   Sammanfattning : Additive manufacturing enables the production of complex multi-material geometries and bulk metallic glass parts beyond their critical casting thickness. The local modification of structure, composition, and properties is explored in this thesis with the aim to design novel composite materials and functional gradients. LÄS MER

4. 3. Tailoring structure and morphology during additive manufacturing of metallic components

   Författare :Jithin James Marattukalam; Björgvin Hjörvarsson; Ulf Jansson; Martin Sahlberg; Lars Nyborg; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Selective laser melting; process parameters; scanning methodologies; AMLOYZR01; bulk metallic glass; 316L SS; grain orientation;

   Sammanfattning : The work described in this thesis explores the use of laser process parameters to functionalize the material properties by the control of microstructure and optimization of morphology in components by selective laser melting. The microstructure in amorphous and crystalline metallic alloy systems is influenced by changing the laser power density and scanning strategies respectively. LÄS MER

5. 4. Modelling of Bulk Metallic Glass formation in Powder Bed Fusion

   Författare :Johan Lindwall; Andreas Lundbäck; Mattias Unosson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

   Sammanfattning : This thesis discusses a model for simulation of the Powder Bed Fusion (PBF) process of metallic powder with the capability to become amorphous. The temperature field in the PBF process is predicted by a three-dimensional thermal finite element model in three dimensions using a layer-by-layer approach, meaning that the scanning strategy of the moving laser spot is consolidated into a single heat source acting on the entire layer momentarily. LÄS MER

7. 5. Crystallization in additive manufacturing of metallic glass

   Författare :Anders Ericsson; Hållfasthetslära; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Amorphous metals; Crystallization; Laser powder bed fusion; Neutron scattering; Phase-field theory; Classical nucleation theory;

   Sammanfattning : Metallic glasses are non-crystalline metals that are obtained by rapid cooling of the melt to bypass crystallization. The amorphous atomic structure shows enhanced properties relative to the crystalline counterpart. For example, enhanced mechanical properties, improved corrosion resistance, as well as excellent soft magnetic properties. LÄS MER