EVOLUTION OF THE γ/γ'MICROSTRUCTURE DURING HIGH- TEMPERATURE CREEP OF A NICKEL-BASE SUPERALLOY

摘要

The evolution of the γ/γ'microstructure of the superalloy SRR99 during creep at 98 deg. C 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.