Sökning: "Nickel-based superalloy"

Visar resultat 21 - 25 av 29 avhandlingar innehållade orden Nickel-based superalloy.

1. 21. Constitutive modelling of an additively manufactured alloy for fatigue lifing in high temperature applications

   Författare :Thomas Lindström; Daniel Leidermark; Håkan Hallberg; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The main objective of the work presented in this Licentiate thesis is to investigate and model the cyclic behaviour of an additively manufactured ductile nickel-based superalloy, with special emphasis on modelling the stabilised material behaviour, which is of interest for fatigue life predictions. Cyclic fatigue tests at different temperatures have been performed to investigate the cyclic mechanical behaviour of the material, where specimens built in different orientations have been used to also study the anisotropic behaviour of the material. LÄS MER

3. 22. Inconel 718 and Hydrogen

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

   Sammanfattning : 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. LÄS MER

4. 23. High temperature fatigue crack propagation behaviour of Inconel 718

   Författare :David Gustafsson; Kjell Simonsson; Johan Moverare; Sören Sjöström; Ulrich Krupp; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : The overall objective of this work has been to develop and evaluate tools for designing against fatigue in gas turbine applications, with special focus on the nickel-based superalloy Inconel 718. The fatigue crack propagation behaviour under high temperature hold times has been studied. LÄS MER

5. 24. Modelling of fatigue crack propagation in Inconel 718 under hold time conditions

   Författare :Erik Lundström; Kjell Simonsson; Tomas Månsson; David Gustafsson; Johan Moverare; Martin Hughes; Linköpings universitet; []
   Nyckelord :;

   Sammanfattning : In this thesis an investigation and modelling of the fatigue crack propagation in the nickel based superalloy Inconel 718, with a special emphasis on the effect of hold times, is presented. The modelling work has been concentrated on describing the hold time fatigue crack propagation by using the concept of a damaged zone in front of the crack tip, which is believed to have a lowered resistance against crack propagation. LÄS MER

7. 25. Modelling of Forming and Welding in Alloy 718

   Författare :Lluís Pérez Caro; Mats Oldenburg; Eva-Lis Odenberger; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Forming; welding; Alloy 718; damage; GISSMO; failure; Hållfasthetslära; Solid Mechanics;

   Sammanfattning : The reduction of fuel consumption and carbon dioxide emissions are currently a key factor for the aviation industry due to major concerns about climate change and more restrictive environmental laws. One way to reduce both fuel consumption and CO2 emissions is by significantly decreasing the vehicle’s weight while increasing engine's efficiency. LÄS MER