Sökning: "Termodynamisk modellering"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden Termodynamisk modellering.

  1. 1. Developing the third generation of Calphad databases: what can ab-initio contribute?

    Författare :Sedigheh Bigdeli; Malin Selleby; Huahai Mao; Nathalie Dupin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Developing the third generation of Calphad databases with more physical basis valid within a wider temperature range is the aim of the present work. Atomistic scale (ab-initio) methods, particularly techniques based on DFT theory, are used for modelling dierent phenomena, so as to gauge the capacity for use in Calphad modelling. LÄS MER

  3. 2. Equilibrium aspects of Cr-alloyed cemented carbides

    Författare :Bartek Kaplan; Malin Selleby; Armando F. Guillermet; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : In view of the extensive use of Cr as a grain growth inhibitor in WC-Co cemented carbides this thesis comprises a combined experimental and ab initio study of a number of critical issues pertaining to phase equilibria of the subsystems to the W-Co-Cr-C system.To be able to predict which of the stable Cr-carbides forms above the solubility limits of Cr and C in the fcc phase the respective solubility of Co in Cr23C6, Cr7C3 and Cr3C2 are investigated experimentally. LÄS MER

  4. 3. Experimental and theoretical study of carbides in the Co-Cr-C system : Structure, alloying and stability

    Författare :Bartek Kaplan; Malin Selleby; Jan Qvick; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : The research presented in this thesis explores the structure, alloying and stability of the carbides in the Co-Cr-C system by using the CALPHAD approach supported by experimental measurements and ab initio calculations.WC-Co based cemented carbide materials consist of hard WC grains and a ductile Co-based binder. LÄS MER

  5. 4. Thermodynamic investigation of systems related to TWIP steels

    Författare :Bonnie Lindahl; Malin Selleby; Ales Kroupa; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : The world is facing serious challenges regarding environmental issues. Carbon dioxide levels increase every day. In an attempt to decrease carbon emissions the automotive industry searches for lighter, stronger materials. TWinning Induced Plasticity (TWIP) steels show an impressive combination of strength and ductility. LÄS MER

  7. 5. Multicomponent diffusional reactions in tool steels : Experiment and Theory

    Författare :Greta Lindwall; Malin Selleby; Karin Frisk; John Ågren; Carelyn Campbell; KTH; []
    Nyckelord :hot-work tool steel; precipitation hardening; DICTRA; coarsening; mobilities; CALPHAD; cobalt; PM tool stees; nitrogen; compound materials;

    Sammanfattning : Many phenomena determining the microstructure of a tool steel and consequently the properties of the material, are governed by multicomponent diffusion. The diffusion driven reactions that take place during, for example, tempering of a hot-work tool steel or when the microstructure develops during hot isostatic pressing of cold-work tool steel, are dependent on the types and amounts of alloying elements. LÄS MER