Search for dissertations about: "Laves Phase"

Showing result 1 - 5 of 22 swedish dissertations containing the words Laves Phase.

  2. 1. Development of a new generation of creep resistant 12% chromium steels: Microstructure of Z-phase strengthened steels

    Author : Masoud Rashidi; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phase transformation; CrNbN; impact toughness; Creep; CrTaN; Laves-phase; atom probe tomography; precipitation hardening; M2N; MX; transmission electron microscopy; coarsening;

    Abstract : Fossil-fuel fired steam power plants provide more than 60% of the electricity generated worldwide, and account for about one third of the global CO2 emissions. Increasing the steam temperature and pressure leads to a higher thermal efficiency of the power plants and thus lower emissions. READ MORE

  4. 2. Alloys in Contact with Molten Salts for Thermal Storage Applications

    Author : Esraa Hamdy Mohamedin; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase transition; Molten salts; High-temperature corrosion; Alumina-forming alloys; Carburisation; Thermal energy storage TES ; Laves phase; Concentrated solar power CSP ;

    Abstract : The combination of a concentrated solar power (CSP) plant and a thermal energy storage (TES) system is a promising technology for power generation, in that it overcomes the challenges commonly faced by renewable energy systems, such as intermittency, dispatchability, and the gap between the energy supply and energy demand. The third generation (Gen3) CSP plants are designed to increase plant efficiency by using supercritical carbon dioxide (sCO2) instead of steam for the Brayton cycle gas turbines, requiring a minimum operating temperature of 750°C for the TES materials. READ MORE

  5. 3. Role of alloying elements in Mo5Si3 intermetallics

    Author : Erik Ström; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microhardness; silicide; alloying; ternary; intermetallic; Laves; hardness; high temperature material; Mo5Si3;

    Abstract : The role of alloying elements in the intermetallic compound Mo5Si3 was studied in the alloying systems Mo5-xMxSi3 (M = Cr, Ti, Nb, Ni, or Co, x = 0.5-2). The effects of the alloying elements were examined by characterising the microstructures and identifying the resulting phases. In the case of Cr and Nb alloying, a solubility of 25% (at. READ MORE

  6. 4. Studies of inorganic crystal structures and gas adsorption process in mesoporous crystals : New approach through analysis of electron charge distribution by synchrotron powder X-ray diffraction

    Author : Norihiro Muroyama; Osamu Terasaki; Clément Sanchez; Stockholms universitet; []
    Keywords : XRD; Mesoporous; Gas adsorption; Laves Phase; MEM; strukturkemi; Structural Chemistry;

    Abstract : Using synchrotron powder XRD experiments, I studied (i) structures of silica mesoporous MCM-41 and MCM-48 crystals, (ii) gas adsorption processes of Ar and N2 in the mesopores of the mesoporous crystals, and (iii) bonding features of CaAl2-xZnx crystals through the analysis of electron charge density distributions. In the case of mesoporous crystals, the following two different approaches were taken depending on the number of observed X-ray reflections1. READ MORE

  7. 5. Metal Hydrogen Interaction and Structural Characterization of Amorphous Materials from first principles

    Author : Robert Johansson; Ralph Scheicher; Olle Eriksson; Rajeev Ahuja; Peter Mohn; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; hydrogen; vanadium; zintl; laves; strain; diffusion; amorphous; dft; molecular dynamics; md; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : In this thesis, first-principles calculations based on density functional theory have been employed to investigate metal hydrogen interaction in transition, p-block and rare earth metals. Furthermore, the accuracy of the stochastic quenching method was tested in describing the structure of amorphous Fe(1-x)Zrx. READ MORE