Sökning: "PM"

Visar resultat 21 - 25 av 305 avhandlingar innehållade ordet PM.

  1. 21. Key Aspects of Sintering Powder Metallurgy Steel Prealloyed with Chromium and Manganese

    Författare :Ola Bergman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Manganese; Prealloyed; Sintering; Mechanical properties; Chromium; Spinel oxide; Powder metallurgy; PM steel; Oxide reduction; Residual oxides; Atmosphere;

    Sammanfattning : The powder metallurgy (PM) process is a cost efficient near net-shape technology suitable for sustainable manufacturing of structural steel components. A drawback with the PM technology is the difficulty to use oxidation sensitive alloying elements, such as Cr and Mn. LÄS MER

  3. 22. A Generator Perspective on Vertical Axis Wind Turbines

    Författare :Fredrik Bülow; Hans Bernhoff; Jens Sørensen; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; PM generator; Wind power; Stator core loss;

    Sammanfattning : The wind energy conversion system considered in this thesis is based on a vertical axis wind turbine with a cable wound direct drive PM generator. Diode rectifiers are used to connect several such units to a single DC-bus and a single inverter controls the power flow from the DC-bus to a utility grid. LÄS MER

  4. 23. Surface Chemical Characteristics of Chromium-alloyed Steel Powder and the Role of Process Parameters during Sintering

    Författare :Dimitris Chasoglou; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carbothermal reaction; sintering atmosphere; depth profiling; XPS AES; HR SEM EDX; water atomized powder; surface coverage; reduction oxidation; PM steels; sintering; Cr-Mn-spinel oxides; surface oxides;

    Sammanfattning : Powder Metallurgy (PM) is a cost efficient method suitable for sustainable production of structural parts that have strict dimensional tolerances and complex geometries. It has been a common practice to utilize Ni and Cu as alloying elements in PM steels, but the high and fluctuating prices of Ni and the concerns around it associated with health hazards as well as the difficulty in recycling Cu lead the PM industry to search for effective alternatives such as Cr and Mn. LÄS MER

  5. 24. Extreme Load Conditions for Wind Powered Direct Drive PM Generators

    Författare :Fredrik Bülow; Uppsala universitet; []
    Nyckelord :;

    Sammanfattning : Wind energy is a rapidly growing energy source with vast potential. Vertical axis wind turbines could be more cost-effective than the three bladed horizontal axis turbines that dominate today. LÄS MER

  7. 25. Deformation and Fatigue Behaviour of Porous and Dense Austenitic Stainless Steel

    Författare :Ulf Lindstedt; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mechanical properties; austenitic stainless steel; PM steel; nitrogen; small cracks; previous particle boundaries; microplasticity; grain size dependence; fatigue; porosity;

    Sammanfattning : PM stainless steels are increasing in use and are expected to do so in the future. A lot of work has been carried out concerning production and sintering of stainless steel powders and on the resulting corrosion behaviour. The deformation behaviour of these materials is less studied. LÄS MER