|About this Abstract
||2023 TMS Annual Meeting & Exhibition
||Advanced Characterization of High-temperature Alloys: Phase Evolution during Manufacturing and Service-induced Deformation
||A Microscopy Investigation on the Nucleation and Propagation of Superlattice Stacking Faults in Nickel-based Superalloys
||Fernando Daniel Leon-Cazares, Regina Schluetter, Francesco Monni, Mark C. Hardy, Catherine Mary Rae
|On-Site Speaker (Planned)
||Fernando Daniel Leon-Cazares
Superlattice intrinsic stacking faults (SISF) are the main culprit for the low temperature creep deformation of modern nickel-based superalloys used in jet engines. These defects were identified over five decades ago, but their nucleation mechanism remains unclear. This work provides the first ever experimental evidence, via transmission electron microscopy, of a SISF nucleating from a cross-slip event in a polycrystalline alloy. This allows the two dissimilar dislocations required to form a SISF to meet on adjacent planes at a precipitate interface. The concept of a nascent fault is introduced: the initial stacking fault that forms on a crystallographic plane and the dislocations of which continue to form coplanar faults as they glide away. Cross-slip and the subsequent fault propagation are detailed considering the resolved shear stresses on the dislocations involved. These findings will guide future characterisation efforts in the field and inform more realistic predictive models of creep behaviour.