Sökning: "Ni-base alloy"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden Ni-base alloy.

  1. 1. High Temperature Corrosion Behaviour of Ni-base Alloys and FeCrAl Alloys – The Influence of Water Vapour

    Författare :Tommy Sand; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cr-evaporation; FeCrAl alloy; Oxidation; Chromia scale; Alumina scale; High-temperature corrosion; Ni-base alloy;

    Sammanfattning : Electricity production, transportation, and manufacturing industry are some of the largest sources of greenhouse gas emissions. In many cases, these processes are carried out at high temperature and energy efficiency is limited by material degradation, so-called ‘high-temperature corrosion’. LÄS MER

  3. 2. Powder bed fusion processing of Ni-base superalloys - Defect formation and its mitigation

    Författare :Hans Gruber; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hot isostatic pressing; Ni-base superalloys; non-metallic inclusions; cracking; additive manufacturing; laser powder bed fusion; defect formation; Alloy 718; powder re-use; IN-738LC;

    Sammanfattning : Powder bed fusion of Ni- and Ni-Fe-base superalloys is actively considered a promising manufacturing technology for critical components for the aerospace and industrial gas turbine industries. Such components often operate under harsh conditions, and hence, high demands are placed on both process and feedstock material to meet the strict safety and long-term reliability requirements. LÄS MER

  4. 3. Microstructural evolution during hot compression of a Ni-base superalloy: Dynamic and post-dynamic recrystallization below the secondary carbide solvus temperature

    Författare :Emil Eriksson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hot compression; Ni-base superalloys; Electron microscopy; Recrystallization;

    Sammanfattning : With an increased demand to lower emissions, the eciency of aircraft engines have to be improved. One way to achieve this is to increase the operation temperature. However, due to the extremely challenging environments in the hot sections of these engines, the current alloys are at their limits. LÄS MER

  5. 4. Oxygen Induced High Temperature Crack Growth in Ni-base Superalloys

    Författare :Leif Viskari; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Diffusion; Environmental influence; Crack growth; Atom probe tomography; Electron Microscopy; Deformation; Crack tip oxidation; Hold-time fatigue;

    Sammanfattning : Oxygen induced crack growth is a serious concern for the performance of Ni-base superalloys. These alloys are used in gas-turbine engines where they are exposed to hightemperatures, mechanical loads and oxygen-rich environments. LÄS MER

  7. 5. Mechanisms of Metal Dusting

    Författare :Peter Szakálos; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; metal dusting; mechanism; driving force; kinetics; high temperature corrosion; carburization; stainlesssteel; Ni-base alloys; iron; alumina formers; FeCrAl; oxidation; carbon nanotubes; discontinuous precipitation; Materials science; Teknisk materialvetenskap;

    Sammanfattning : The primary intention with this Doctoral thesis is to fillin the knowledge gaps and raise the level of understandingregarding the different metal dusting mechanisms in general andexplain the process in detail for high alloyed materials.Considerable effort is put into identifying the driving forcesand elucidating the diffusional processes in metal dusting. LÄS MER