Sökning: "nitrogen iron"

Visar resultat 16 - 20 av 91 avhandlingar innehållade orden nitrogen iron.

  1. 16. 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

  3. 17. Non-cyanobacterial nitrogen fixation insights in humic freshwater lakes and ponds

    Författare :Leyden Fernandez-Vidal; Stefan Bertilsson; Sari Peura; David Walsh; Uppsala universitet; []
    Nyckelord :humic lakes; thaw ponds; non-cyanobacterial diazotrophs; nitrogen fixation; nitrogenase;

    Sammanfattning : The biological basis of nitrogen fixation beyond the canonical role of Cyanobacteria is not well understood in freshwater ecosystems. To address this gap in knowledge, the main objective of this thesis is to study non-cyanobacterial nitrogen fixation in freshwater lakes and ponds. LÄS MER

  4. 18. Characteristics and Sintering of Fine Water-atomized and Carbonyl Iron Powder

    Författare :Johan Wendel; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sintering; powder metallurgy; iron powder; dilatometry; surface analysis; thermal analysis;

    Sammanfattning : Various types of iron powder are extensively used in the powder metallurgy (PM) industry. Water-atomized iron powder is commonly used as the base in many low-alloyed steel products manufactured through the conventional 'press and sinter' route, while carbonyl iron powder is often used for metal injection moulded (MIM) components. LÄS MER

  5. 19. Factors Influencing the Formation of Shrinkage Porosity in Grey Cast Iron

    Författare :Lennart Elmquist; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CET; Oxygen; Columnar zone; Grey iron; Shrinkage porosity; Equiaxed zone; Solidification; DAAS; Hydrogen; Primary austenite;

    Sammanfattning : The presence of shrinkage defects is of major concern in the production of grey iron castings. This type of defect can penetrate through the casting as a three-dimensional network. LÄS MER

  7. 20. Crystallization on the Mesoscale : Self-Assembly of Iron Oxide Nanocubes into Mesocrystals

    Författare :Michael Agthe; Lennart Bergström; German Salazar-Alvarez; Tommy Nylander; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Self-assembly; iron oxide nanocubes; mesocrystal; small angle X-ray scattering; video microscopy; QCM-D; Materials Chemistry; materialkemi;

    Sammanfattning : Self-assembly of nanoparticles is a promising route to form complex, nanostructured materials with functional properties. Nanoparticle assemblies characterized by a crystallographic alignment of the nanoparticles on the atomic scale, i.e. mesocrystals, are commonly found in nature with outstanding functional and mechanical properties. LÄS MER