Gas turbines in power generation systems use both nickel and cobalt-based superalloys for vanes, blades, discs and combustion chamber components. Cobalt-based superalloys have the advantage over nickel based superalloys in that they have a higher thermal conductivity and hence a greater thermal shock resistance, a greater resistance to thermal fatigue and also a better corrosion resistance. However, in some applications coatings have to be applied to such alloys because of their poor oxidation resistance. The creep strength of cobalt-based superalloys depends primarily on solid solution strengthening and the interaction between the hard carbides and alloy defects, such as dislocations and stacking faults. There is a need to develop an understanding of the microstructural changes that occur in cobalt-based superalloys, with both time and temperature, for life prediction, refurbishment and failure investigations.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:603100 |
| Date | January 2007 |
| Creators | Oates, David L. |
| Publisher | Loughborough University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://dspace.lboro.ac.uk/2134/15182 |
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