Sökning: "alloy design"

Visar resultat 16 - 20 av 132 avhandlingar innehållade orden alloy design.

  1. 16. Rhodium diesel-reforming catalysts for fuel cell applications

    Författare :Xanthias Karatzas; Lars J. Pettersson; James Spivey; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Autothermal reforming; auxiliary power unit; BET; chemisorption; diesel; fuel cell; hydrogen; monolith; reforming catalyst; reformer design; Rh; RhPt alloy; TEM; TPO; TPR; XRD; XPS; zone coating; Chemical engineering; Kemiteknik;

    Sammanfattning : Heavy-duty diesel truck engines are routinely idled at standstill to provide cab heating or air conditioning, and in addition to supply electricity to comfort units such as radio and TV. Idling is an inefficient and unfavorable process resulting in increased fuel consumption, increased emissions, shortened engine life, impaired driver rest and health, and elevated noise. LÄS MER

  2. 17. Platinum-free Electrocatalysts : Design, Synthesis, and Energy Applications

    Författare :Yi Yang; Inna Soroka; Carina Lagergren; Serhiy Cherevko; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pt-free electrocatalysts; γ-radiation induced synthesis; size; morphology; structure; and composition of nanocatalysts; ORR; catalytic activity and durability; formation mechanism of catalyst materials in aqueous solutions.; Kemi; Chemistry;

    Sammanfattning : Pt is one of the most commonly used catalysts for green energy applications, such as fuel cells, electrolyzers, and dye-sensitized solar cells. Although enormous effort has been put into improving the catalytic activity and minimizing the usage of Pt in the catalysts, the low abundance and high price of Pt still limit the large-scale commercialization of green energy devices and facilities. LÄS MER

  3. 18. Process chain simulation of forming, welding and heat treatment of Alloy 718

    Författare :Joachim Steffenburg-Nordenström; Lars-Erik Svensson; Lars-Erik Lindgren; Fredrik Niklasson; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Forming; Welding; Stress relieve annealing; Heat treatment; Finite Element Simulation; Manufacturing process chain; Alloy 718; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

    Sammanfattning : Manufacturing of aero engine components requires attention to residual stress and final shape of the product in order to meet high quality product standards.This sets very high demands on involved manufacturing steps to meet design requirements. LÄS MER

  4. 19. Powder degradation during powder bed fusion processing: impact of processing conditions and alloy composition

    Författare :Ahmad Raza; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; residual oxygen; powder bed fusion – electron beam; powder degradation; oxidation; Alloy 718; AlSi10Mg; powder bed fusion - laser beam; TiAl6V4; Hastelloy X.; sublimation; spatter particles; Keywords: additive manufacturing;

    Sammanfattning : In the recent decade, powder bed fusion (PBF) metal additive manufacturing (AM) has attracted huge attention both from the industry and the research community. This effort has helped mature PBF technology as a potential alternative to conventional manufacturing processes as casting, machining, forging, etc. LÄS MER

  5. 20. Hunting Hydrogen : Structure-property relations in High Entropy Alloy-based metal hydrides

    Författare :Gustav Ek; Martin Sahlberg; Ulrich Häussermann; William I.F. David; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrogen; metal-hydride; High Entropy Alloy; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi;

    Sammanfattning : Metal hydrides have many uses when switching the energy system from fossil fuels to renewable sources, such as rechargeable batteries, hydrogen storage, hydrogen compression and thermal storage. State of the art materials for these applications such as LaNi5 and TiFe, however, suffer certain limitations such as degradation during repeated hydrogen cycling and harsh activation conditions for initial hydrogen uptake, promoting the need for novel materials. LÄS MER