Sökning: "grain boundaries"

Visar resultat 6 - 10 av 199 avhandlingar innehållade orden grain boundaries.

  1. 6. Inclusions and/or Particles Engineering for Grain Refining Purposes in Ferritic Fe-20mass%Cr alloys

    Författare :Jesper Janis; Pär Jönsson; Keiji Nakajima; Lauri Holappa; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Inclusions; Particles; Grain size; High Cr; Ferritic; Grain refining; Solidification; Pinning effect; Stainless steel; Oxides; Nitrides; Metallurgical process engineering; Metallurgisk processteknik;

    Sammanfattning : Compared to more common used austenitic stainless steels, ferritic stainless steels contain very low amounts of the expensive alloying element Ni. In addition, they have good corrosion properties, but are sometimes suffering from poor weldability and bad mechanical properties. LÄS MER

  3. 7. Strength and Stability of Interfaces in Cemented Carbides

    Författare :Mikael Christensen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; adhesion; segregation; plastic deformation; microstructure; interfaces; electron structure calculations; cermets; sintering; infiltration; cemented carbides; grain boundaries; cutting tools; density-functional theory; hardmetals; WC-Co; wetting;

    Sammanfattning : Cemented carbides are hard composite materials of great technological importance. They are widely used as tool materials in a large variety of applications where the demands on hardness and toughness are high, including e.g.≈mining, turning, cutting, and milling. LÄS MER

  4. 8. Atomistic Simulation of Interfaces: Proton transport across BaZrO3 grain boundaries

    Författare :Edit Ahlberg Helgee; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Due to the negative environmental effects of fossil fuels it is necessary to develop technology that may reduce or eliminate the need for oil and coal. Fuel cells are highly important in this context as they provide an efficient way of converting chemical energy into electrical energy. LÄS MER

  5. 9. Quantum Transport Theory in Graphene

    Författare :Anders Bergvall; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantum coherent electron transport; nanoribbons; FT-LDOS; grain boundaries; tight-binding; graphene;

    Sammanfattning : In this thesis, we focus on different aspects of electron transport in nanostructured graphene (such as graphene nanoribbons). Wedevelop and implement numerical methods to study quantum coherent electron transport on an atomistic level, complemented by analytical calculations based on the Dirac approximation valid close to the points $\vec{K}$ and $\vec{K}^\prime$ in the graphene Brillouin zone. LÄS MER

  7. 10. Multiscale Modeling of Interfaces

    Författare :Sven Johansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; misfit; Peierls-Nabarro model; semicoherent interfaces; interfaces; cemented carbides; grain boundaries; microstructure; VN precipitates; density-functional theory;

    Sammanfattning : Understanding strength and stability of interfaces between dissimilar materials or phases is a highly active field of contemporary materials research. Knowledge of interface structure and energetics is important for modeling of complex materials both on a mechanical and thermodynamical level as well as for many functional properties. LÄS MER