Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Aging of γ′ Precipitates at 750 °C in the Nickel-Based Superalloy AD730TM: A Thermally or Thermo-Mechanically Controlled Process?

Abstract : The microstructural stability during aging at 750 °C of the γ/γ′ nickel-based superalloy AD730TM is investigated in this work. Strain-free aging and aging during fatigue tests are conducted, with a focus on the influence of the strain ratio, the maximum applied strain, and the cycle waveform (with or without dwell). Two classical mechanisms of γ′ precipitates aging are identified at 750 °C: the coarsening of small spherical γ′ precipitates via the thermally-activated Ostwald ripening process and the coalescence of at least two precipitates into one. These mechanisms appeared to be concomitant during aging. It has been demonstrated that the coarsening kinetics of γ′ precipitates can be described by a classical Lifshitz-Slyozow-Wagner (LSW) equation. The introduction of a cyclic strain during aging at 750 °C increases the coarsening kinetics by means of changes in the volume diffusion of γ′-forming elements and of constraint misfit effects. More precisely, it is shown that the higher the maximum applied strain and/or the strain rate, the higher the coarsening rates. Finally, dwell-fatigue promotes the activation of the γ′ coalescence at 750 °C.
Type de document :
Article dans une revue
Liste complète des métadonnées

https://hal-mines-paristech.archives-ouvertes.fr/hal-02901655
Contributeur : Magalie Prudon <>
Soumis le : vendredi 17 juillet 2020 - 14:03:54
Dernière modification le : jeudi 30 juillet 2020 - 03:58:44

Lien texte intégral

Identifiants

Collections

Citation

Nicolas Mrozowski, Gilbert Henaff, Florence Hamon, Anne-Laure Rouffié, Jean-Michel Franchet, et al.. Aging of γ′ Precipitates at 750 °C in the Nickel-Based Superalloy AD730TM: A Thermally or Thermo-Mechanically Controlled Process?. Metals, MDPI, 2020, 10 (4), pp.426. ⟨10.3390/met10040426⟩. ⟨hal-02901655⟩

Partager

Métriques

Consultations de la notice

31