Small angle neutron scattering comparative investigation of Udimet 520 and Udimet 720 samples submitted to different ageing treatments

Udimet 520 and Udimet 720 samples submitted to different annealing temperatures and ageing times have been investigated by small angle neutron scattering (SANS), with the aim to study precipitates phases microstructural evolution and materials’ behaviour.These materials are γ′ (Ni3Al, Ti) precipitation hardened nickel-based superalloys possessing high strength, corrosion resistance and metallurgical stability. They are mainly adopted in high temperature environment, having found applications over a very wide range of temperature. Their importance has increased thanks to their good balance of mechanical properties and economic potential.Information on the thermal treatment effects has been obtained, in particular concerning precipitate size and volume fraction distributions. The results contribute to confirm SANS to a level of industrial applicability in the considered sectors.

► SANS allows studying the nano-structural evolution of superalloys after thermal treatments. ► SANS allows evaluating the precipitates’ dimensions and volume contents of superalloys. ► SANS can be regularly used to evaluate the accumulated damage in Udimet superalloys. ► Udimet 520 and Udimet 720 demonstrate a different ability to form precipitates at 800–900 °C. ► Udimet 720, after ageing, may form a more stable and strength nano-structure than Udimet 520.