Kinetics of cubic to tetragonal transformation in Ni-V-X alloys.

Helena Zapolsky (1) , Sebastien Ferry (1) , Xavier Sauvage (1) , Didier Blavette (1) , Long-Qing Chen (2)

1 GPM - Groupe de physique des matériaux
2 Material Science and Engineering

Computer simulations based on the Khachaturyan's Onsager diffusion equation have been performed to model the microstructure evolution during the cubic-to-tetragonal transformation in Ni-based alloys. A 2D model was employed. The fcc-DO22 ordering has been studied as a model case of this type of transformations. A particular emphasis is on the formation mechanism of DO22 monovariant structures. Computer simulations demonstrate that strain-induced interactions between coherent DO22 precipitates lead to the formation of intermediate two-variant chessboard-like structures, which are found to be unstable and coalesce into subsequent single-variant maze structures. It is shown that the stability of the chessboard-like structures is very sensitive to lattice misfits. These simulation results are in good agreement with TEM observations.

Mots clés: Physical Sciences

Helena Zapolsky, Sebastien Ferry, Xavier Sauvage, Didier Blavette, Long-Qing Chen. Kinetics of cubic to tetragonal transformation in Ni-V-X alloys.. Philosophical Magazine, 2010, 90 (01-04), pp.337-355. ⟨10.1080/14786430903179562⟩. ⟨hal-00556065⟩