Search for dissertations about: "dislocation density"

Showing result 16 - 20 of 64 swedish dissertations containing the words dislocation density.

  2. 16. Very high cycle fatigue of duplex stainless steels and stress intensity calculations

    Author : Muhammad Waqas Tofique; Jens Bergström; Nils Hallbäck; Anders Gåård; Johan Moverare; Karlstads universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Very high cycle fatigue; duplex stainless steel; ultrasonic fatigue testing; distributed dislocation dipole technique; Materialteknik; Materials Engineering;

    Abstract : Very high cycle fatigue (VHCF) is generally considered as the domain of fatigue lifetime beyond 10 million (107) load cycles. Few examples of structural components which are subjected to 107-109 load cycles during their service life are engine parts, turbine disks, railway axles and load-carrying parts of automobiles. READ MORE

  4. 17. Dislocations in silicon

    Author : Niklas Lehto; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fysik; Fysik;

    Abstract : The topic of this thesis is theoretical studies of the electrical and structural properties in the elemental semiconductor silicon. Because of the numerous and powerful applications of semiconductors, e.g., rectifiers, transistors, solar cells and lasers, they have been the focus of huge amounts of research. READ MORE

  5. 18. Physically based models of metal plasticity

    Author : Konstantin Domkin; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datorstödd maskinkonstruktion; Computer Aided Design;

    Abstract : This work is focussing on the material modelling aspects in simulation of forming processes. The research question is: Do physical based material models have any advantages compared to the more common type of engineering models used in simulation of forming processes? The success of performing useful simulations of forming processes depends very much on the accuracy of the used material description. READ MORE

  6. 19. Inconel 718 and Hydrogen

    Author : Niklas Ehrlin; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; IN718 Hydrogen Embrittlement Cathodic Charging;

    Abstract : The nickel based superalloy IN718 is known to be sensitive to hydrogen, causing degradation of its mechanical properties. The degrading mechanism commonly proposed is based on an increased mobility and density of dislocations, caused by the dissolved hydrogen. This results in a decreased yield stress and a premature fracture. READ MORE

  7. 20. Physically based model for plasticity and creep of Ti-6Al-4V

    Author : Bijish Babu; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

    Abstract : Albeit Ti-6Al-4V has numerous salient properties, its usage for certain applications is limited due to the challenges faced during manufacturing. Understanding the dominant deformation mechanisms and numerically modelling the process is the key to overcome this hurdle. This work investigates plastic deformation of the alloy at strain rates from 0. READ MORE