Alloys for high-temperature power applications
Alloys for high-temperature power applications that are strong, corrosion resistant and economically viable are critical for the operation of power generation plants at higher temperatures. Operation at high temperature can lead to energy conversion efficiencies of >50%, which will not only reduce running costs, but also extend the lifetime of fossil fuels and/or reduce the carbon footprint of the plants. In this project, iron-based austenitic steels strengthened with Laves phase precipitates, and alloyed with aluminum for improved oxidation resistance, e.g. Fe-20Cr-20Ni-2Nb-5Al (at.%), are being studied. The project aims to generate finer, higher volume fractions of Laves precipitates in the matrix by using enhanced nucleation on dislocations introduced through cold work. These precipitates will increase the strength and also minimize the formation of grain boundary precipitates, thus retarding the growth of the latter and extending the creep life of the alloy. The precipitates are being characterized after both static ageing and creep using transmission electron microscopy (TEM), and TEM hot in-situ straining experiments are being used to examine the deformation mechanisms.
Faculty contact: Ian Baker