Evolution of the γ/γ′ microstructure during high-temperature creep of a nickel-base superalloy

The evolution of the gamma/gamma' microstructure of the superalloy SRR99 during creep at 980 degreesC and 200 MPa has been characterised by Fourier analysis of scanning electron microscope images. Different kinetics of this process were found in the primary and secondary dendrite arms. Changes of the structure period and interface tilt are correlated with the accumulated creep strain. Possible mechanisms for the correlation of microstructural evolution and high-temperature creep deformation are discussed. (C) 2000 Elsevier Science Ltd. Published by Elsevier Science Ltd. All rights reserved.