Sökning: "John Ågren"

Visar resultat 16 - 20 av 26 avhandlingar innehållade orden John Ågren.

  1. 16. WC grain growth during sintering of cemented carbides : Experiments and simulations

    Författare :Karin Mannesson; John Ågren; Annika Borgenstam; Håkan Engqvist; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cemented carbide; Grain growth; Abnormal grain growth; Image analysis; Modeling; 3-D grain size distribution; Inverse Saltykov; Materials science; Teknisk materialvetenskap;

    Sammanfattning : Cemented carbides are composite materials consisting of a hard carbide and a ductile binder. They are powdermetallurgically manufactured, where liquid-phase sintering is one of the main steps. The most common cemented carbide consists of WC and Co and it is widely used for cutting tools. LÄS MER

  3. 17. Modeling the Microstructure Evolution During and After Hot Working in Martensitic Steel

    Författare :Nima Safara Nosar; John Ågren; Göran Engberg; Hans-Olof Andrén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modeling; Martensitic steel; Carbides; Carbide size distribution; Carbide volume fraction; Carbide shape factor; Modellering; Martensitiskt stål; karbider; karbidstorleksfördelning; karbidvolymfraktion; karbidformfaktor; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : In this study, the goal is to predict the microstructure evolution during and after the hot working of a martensitic stainless steel with 13% chromium using a physically-based model in the form of a MATLAB toolbox. This model is based on dislocation density theory and consists of coupled sets of evolution equations for dislocation, vacancies, recovery, recrystallization, and grain growth. LÄS MER

  4. 18. ICME guided study of mass transport in production and application of cemented carbides

    Författare :Armin Salmasi; Henrik Larsson; Lars Höglund; Andreas Blomqvist; Joakim Odqvist; John Ågren; José Garcia; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cemented carbides; non-homogeneous structures; liquid phase migration; ICME; CALPHAD; materials design; viscosity; diffusion; mass transport; thermodynamics; kinetics; ab-initio; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : Cemented carbides are metallic composites consisting of a WC hard phase and a ductile binder, usually Co-based, produced by powder metallurgy and sintering. Cemented carbides are an essential part of modern material and manufacturing processes. LÄS MER

  5. 19. ICME guided development of cemented carbides with alternative binder systems

    Författare :Martin Walbrühl; John Ågren; Annika Borgenstam; Henrik Larsson; Claudio Miguel Lousada Patricio; Jan Qvick; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cemented carbide; ICME; Materials Design; alternative binder; hardness; AIMD; liquid diffusion; frozen-in solubilities; DICTRA; surface gradients; labyrinth factor; Materials Science and Engineering; Teknisk materialvetenskap;

    Sammanfattning : The development of alternative binder systems for tungsten carbide (WC) based cemented carbides has again become of relevance due to possible changes in EU regulations regarding the use of Cobalt (Co). A framework for the ICME (Integrated Computational Materials Engineering) based Materials Design is presented to accelerate the development of alternative binder systems. LÄS MER

  7. 20. Microstructure and properties of welds in the lean duplex stainless steel LDX 2101

    Författare :Elin M. Westin; John Ågren; Hannu Hänninen; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Duplex stainless steel; welding; HAZ; nitrogen; manganese; microstructure; austenite formation; phase balance; precipitates; element distribution; segregation; depletion; solidification; pitting corrosion resistance; solidification; element loss; evaporation; deposition; weld oxide; thermo-mechanical simulation; thermodynamic modelling; EPMA; XPS; post-weld cleaning; pickling; Metallurgical process and manufacturing engineering; Metallurgisk process- och produktionsteknik;

    Sammanfattning : Duplex stainless steels can be very attractive alternatives to austenitic grades due to their almost double strength at equal pitting corrosion resistance. When welding, the duplex alloys normally require addition of filler metal, while the commodity austenitic grades can often be welded autogenously. LÄS MER