VHCF life of AM1 Ni-based single crystal superalloy after pre-deformation

Satoshi Utada (1, 2) , Luciana Maria Bortoluci Ormastroni (1) , Jérémy Rame (2) , Patrick Villechaise (3) , Jonathan Cormier (3)

1 PPrime [Poitiers] - Institut Pprime [UPR 3346]
2 Safran Aircraft Engines
3 ENDO - ENDOmmagement et durabilité [Institut Pprime]

VHCF properties of the Ni-based single crystal superalloy AM1 with pre-deformation have been investigated at 1000 °C. Pre-deformed material did not present life debit under fully reversed conditions (R =-1). Pre-deformation decreased VHCF lifetime under high mean stress conditions (R = 0.5) with a presence mode I surface crack initiation. The pre-deformed material has microstructure coarsened bands lying on the former {111} slip planes, facilitating microstructure shearing during VHCF at R = 0.5. Slip traces increased surface roughness, causing surface recrystallization and fatal surface crack. Rejuvenation heat treatment after pre-deformation can restore the microstructure and the fatigue life. Highlights VHCF life of pre-deformed Ni-based single crystal superalloy at 1000 °C. Pre-deformation has no effect on the VHCF life at R =-1. Pre-deformation induces VHCF life debit at R = 0.5 and high mean stress. Rejuvenation heat treatment restores VHCF life.

Mots clés: Ni-based single crystal superalloy; pre-deformation; very high cycle fatigue; rejuvenation

Domaines: Sciences de l'ingénieur [physics]

Satoshi Utada, Luciana Maria Bortoluci Ormastroni, Jérémy Rame, Patrick Villechaise, Jonathan Cormier. VHCF life of AM1 Ni-based single crystal superalloy after pre-deformation. International Journal of Fatigue, 2021, 148, pp.106224. ⟨10.1016/j.ijfatigue.2021.106224⟩. ⟨hal-03452730⟩