Sökning: "nickel alloys"

Visar resultat 1 - 5 av 93 avhandlingar innehållade orden nickel alloys.

  1. 1. Microstructure of Nickel-Chromium Superalloys

    Författare :Mattias Thuvander; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; segregation; TEM; nickel alloy; grain boundary; APFIM; SIMS; carbide; precipitation; ordering; boride;

    Sammanfattning : The microstructure of nickel-chromium superalloys has been investigated using several advanced microanalytical techniques; atom probe field ion microscopy (APFIM), transmission electron microscopy (TEM) together with energy dispersive X-ray analysis (EDX) and electron energy loss spectroscopy (EELS), secondary ion mass spectroscopy (SIMS) and optical microscopy (OM). The features primarily considered include precipitation, segregation and ordering. LÄS MER

  3. 2. On the hot crack formation during solidification of iron-base alloys

    Författare :Karin Hansson; KTH; []
    Nyckelord :hot cracking; hot tearing; cracking fracturing ; tearing; ductility; brittleness; embrittlement; fractures; ductile brittle transition; solidification; iron; copper; nickel; Invar; steels; free machining steels; stainless steels; penetration; crack;

    Sammanfattning : Hot cracking during solidification is a severe problem inmany casting processes, for example in continuous casting.Combinations of low strength and low ductility of the materialat high temperatures and applied tensile stress can cause hotcracking. LÄS MER

  4. 3. Density functional study of mono-vancacies in metals and austenitic steel alloys

    Författare :Delczeg Lorand; Vitos Levente; Korzhavyi Pavel; Ann E. Mattsson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; atomic defects; metalls; alloys; vacany; vacancy formation energy;

    Sammanfattning : Trough the following pages a comprehensive study of open structures will be shown, including mono-vacancy calculations and open surfaces. These are electronic structure calculations using density functional theory within the exact muffin tin method. LÄS MER

  5. 4. The Formation and Breakdown of Passive Film on Ni Alloys : in situ synchrotron studies

    Författare :Alfred Larsson; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Passivity; Corrosion; Degradation; Nickel alloys; synchrotron; in situ; Fysicumarkivet A:2023:Larsson;

    Sammanfattning : Corrosion results in huge annual costs and a large environmental footprint. The corrosion rate of some alloys can be made negligible by the presence of a spontaneously forming oxide film on the surface, a so-called passive film. Famous examples of alloys exhibiting passivity are stainless steels. LÄS MER

  7. 5. Nickel allergy in a Swedish adolescent population and its relation to orthodontic treatment and lifestyle factors

    Författare :Ronny Fors; Berndt Stenberg; Maurits Persson; Arne Hensten; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; adolescent; dental plaque; lifestyle; nickel; oral; orthodontic treatment; patch test; questionnaire; sensitisation; tolerance; Orthodontics; Ortodonti;

    Sammanfattning : Nickel stands out as the main cause of contact allergy in both children and adults, which has given rise to concern and the introduction of regulations by official bodies. Today´s youths are frequently exposed to body piercing and orthodontic treatment. LÄS MER