Search for dissertations about: "metallic glasses"

Showing result 1 - 5 of 17 swedish dissertations containing the words metallic glasses.

2. 1. Functional Metallic Glasses

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

   Abstract : 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. READ MORE

4. 2. Designing metallic glasses : Alloying, properties, and degrees of freedom

   Author : Maciej Kaplan; Björgvin Hjörvarsson; Gunnar Pálsson; Jochen Schneider; Susanne Norgren; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; amorphous alloys; enthalpy of mixing; glass formation; thermal stability; thermodynamics; mechanical properties; corrosion resistance; hydrogen;

   Abstract : The present design rules for metallic glasses with respect to glass formation, thermal stability (resistance to crystallisation), and material properties can still be improved. A main design rule is to use thermodynamic calculations to determine the composition of eutectic points in the phase space. READ MORE

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

   Author : Inga Katharina Goetz; Jochen M. Schneider; Björgvin Hjörvarsson; Ulf Jansson; Maria Teresa Pérez Prado; Uppsala universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

6. 4. Computational studies on 2D and 3D amorphous solids : Investigation of structure-property relationship

   Author : Emel Gürbüz; Biplab Sanyal; Andreas Larsson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Amorphous solids; Metallic glasses; Classical molecular dynamics simulations; Thermal transport; Density functional theory; 2D glasses; Vibrational properties; Magnetism; Optical properties;

   Abstract : Amorphous materials represent a large and diverse family, with many questions still remaining unanswered regarding their structure-property relationship. The structural complexity of these materials poses challenges for simulations in contrast to crystalline materials where density func­tional theory (DFT) can be used easily by exploiting the translation symmetry. READ MORE

7. 5. The interaction of hydrogen with metallic glass

   Author : Johan Bylin; Gunnar K. Pálsson; Ralph H. Scheicher; Gabriella Andersson; Astrid Pundt; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; metallic glass; hydrogen; thin film; density functional theory; stochastic quenching; molecular dynamics; x-ray diffraction; pair distribution function; neutron reflectometry; volume expansion; elastic hydrogen-hydrogen interaction; dipole force tensor; electronic structure; optical conductivity; resistivity; optical transmission; x-ray photoelectron spectroscopy; thermodynamic driving force; Gibbs free energy; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Abstract : Combining theoretical ab initio calculations with high-purity thin film sample synthesis and in situ measurements is a compelling way to bridge the gap in our understanding concerning hydrogen in metallic glasses, which is the primary work of this dissertation thesis. The main emphasis has been on how hydrogen affects the structure of metallic glasses, and how those changes influence not only the electronic properties of the amorphous metals but also their thermal stability. READ MORE