An experimental investigation, combining synchrotron X-ray powder diffraction, small-angle neutron scattering and transmission electron microscopy, has been undertaken to study the microstructure of nanoprecipitates in a nickel-based superalloy. Upon increasing the ageing time during a heat-treatment process, the average size of the precipitates first decreases before changing to a monotonically growth stage. Possible reasons for this observed structural evolution, which is predicted thermodynamically, are suggested.
