Sökning: "W Si2"

Hittade 4 avhandlingar innehållade orden W Si2.

  1. 1. On the Oxidation Behaviour of MoSi2 and (Mo,W)Si2 - The Influence of Oxygen and Water Vapour

    Författare :Kristina Hansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; temperature dependence; oxidation; Mo2 OH 2; MoSi2; Mo; W Si2; water vapour;

    Sammanfattning : This thesis deals with the oxidation of a clay-bonded MoSi2 composite (KanthalSuper 1800) and a clay-bonded (Mo,W)Si2-based composite (KanthalSuper 1900) which are used as heating elements at temperatures of up to approximately 1800°C and 1850°C, respectively, in industrial furnaces. These ceramics are ideal for use at these temperatures due to their excellent oxidation behaviour at high temperatures, which is ascribed to the formation of a protective silica scale. LÄS MER

  3. 2. Oxidation of MoSi2-based materials with the addition of W, B and Al

    Författare :Linda Ingemarsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : MoSi2-based composites are intermetallic materials that combine metallic and ceramic properties. Because of their excellent oxidation resistance above 1000°C, they are commonly used in high temperature applications, such as furnace heating elements, where they can be used up to approximately 1800°C. LÄS MER

  4. 3. Negative Ions Interacting with Photons and Electrons

    Författare :Anton Lindahl; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Negative ions; electron correlation; electron affinity; photodetachment; electron collision;

    Sammanfattning : Negative ions are atoms or molecules where an extra electron is bound to neutral system. The nature of negative ions differs fundamentally from neutral and positive systems. The induced dipole potential responsible for the binding of the extra electron supports only a few bound states with relatively small binding energies. LÄS MER

  5. 4. The Influence of Water Vapour on the Oxidation Behaviour of High-temperature Materials Microstructure investigation using analytical electron microscopy

    Författare :Jun Eu Tang; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEM; EDS; SEM; oxidation; microstructure; water vapour; stainless steel; vaporisation; FIB;

    Sammanfattning : This thesis covers the analytical electron microscopy work carried out on samples exposed to high-temperature oxidation in O2 atmospheres with the intention of investigating the effect of oxygen and water vapour. SEM/EDS, TEM/EDS and diffraction techniques, complemented by FIB precision milling, were employed to characterise the formed oxide scales as well as the material directly under the scale in order to understand the mechanisms that influence the corrosion process. LÄS MER