Sökning: "Hot compression"

Visar resultat 1 - 5 av 51 avhandlingar innehållade orden Hot compression.

  1. 1. 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

  3. 2. On Peritectic Reactions and Transformations and Hot Forming of Cast Structures

    Författare :Hani Nassar; Hasse Fredriksson; Rian Dippenaar; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; peritectic reactions; massive transformations; thermal analysis; Fe-base alloys; steels; growth irregularities; hot forming; compression testing; flow stress; grain size.; Metallurgical manufacturing engineering; Metallurgisk produktionsteknik; Metallurgical process engineering; Metallurgisk processteknik;

    Sammanfattning : This thesis deals with peritectic reactions and transformations that occur during the solidification of many alloys. Peritectics are believed to be a major cause of crack-formation in many steels, thus, good knowledge of the mechanisms by which these phenomena occur is essential for preventing such defects. LÄS MER

  4. 3. High temperature properties of polycrystalline Mo(Si,Al)2: compression and oxidation

    Författare :Aina Edgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hot compression; Mo Si; Al 2; microstructure; heating element; mechanical properties; oxidation;

    Sammanfattning : Electrification of industrial heating processes holds great promise for reducing CO2 emissions. Large furnaces operating at elevated temperatures and in demanding atmospheres are complicated but indeed important to electrify. LÄS MER

  5. 4. Modeling the Microstructural Evolution during Hot Deformation of Microalloyed Steels

    Författare :Linda Bäcke; Stefan Jonsson; Eric J. Palmiere; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; modeling; austenite; microalloyed steels; hot deformation; microstructure evolution; static recrystallization; dynamic recrystallization; metadynamic recrystallization<; Materials science; Teknisk materialvetenskap;

    Sammanfattning :   This thesis contains the development of a physically-based model describing the microstructural evolution during hot deformation of microalloyed steels. The work is mainly focused on the recrystallization kinetics. During hot rolling, the repeated deformation and recrystallization provides progressively refined recrystallized grains. LÄS MER

  7. 5. Spark Assisted Compression Ignition, SACI

    Författare :Håkan Persson; Förbränningsmotorer; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flame propagation; PLIF; LDV; chemiluminescence imaging; residuals; negative valve overlap; low temperature combustion; SACI; spark assistance; HCCI; turbulence; charge stratification; cycle to cycle;

    Sammanfattning : The strong focus on decreasing carbon dioxide emissions due to limited natural resources of fossil fuel as well as alarming climate changes drives the research and development of our prime mover, the combustion engine, faster then ever. The minimum requirement is a power source with increased efficiency while emitting ultra low levels of hazardous local and regional emissions. LÄS MER