Effect of Incremental Deformation Path on the Microstructural Evolution of the γ-γ′ Nickel-Based Superalloy René 65

The focus of this study is on the microstructural evolutionMicrostructural evolution of the γ-γ′ nickel-based superalloyNickel-based superalloy René 65René 65 under monotonic and incremental deformationIncremental deformation paths. Here, incremental deformationIncremental deformation is defined as the alternation of small deformations and short dwell times, representing the deformation path processed during a ring rollingRing rolling. Incremental and monotonic deformation paths are performed using hot torsion and hot compression experiments, and their resulting microstructuresMicrostructure are compared. For a given final strain, strain rateStrain rate and temperature, a monotonic deformation generates a higher fraction of recrystallizationRecrystallization than an incremental deformationIncremental deformation path does, for both torsion and compression experiments. Further experiments on interrupted incremental and monotonic compression deformation conditions are conducted to better understand the impact of dwell time on recrystallizationRecrystallization. Static recovery and γ′ precipitationPrecipitation evolution are two potential microstructural mechanisms discussed in this paper that could occur during dwell time and slow down the recrystallizationRecrystallization evolution for incremental deformationIncremental deformation conditions.