Plasticity assisted redistribution of solutes leading to topological inversion during creep of superalloys
Résumé
We have studied the large-scale plasticity assisted topological inversion in a Ni-based superalloy after creep at 850 °C. Multi-scale characterization from the micro- to the near-atomic scale was used to unravel the processes governing topological inversion of a Ni-based single crystal superalloy and reconstruct the resulting three-dimensional microstructure. A plasticity assisted redistribution of interacting solutes mechanism, where shearing dislocations mass-transport solutes, is proposed to explain the transition from a rafted to intricately interconnected (inverted) structure. The interplay between microstructural evolution and mechanical behavior is discussed in terms of applied stress and microstructural features, relating atomic-scale processes to macro-scale behavior.