In Situ Characterization of Inconel 718 Post-Dynamic Recrystallization within a Scanning Electron Microscope

Microstructure evolution within the post-dynamic regime following hot deformation was investigated in Inconel 718 samples with different dynamically recrystallized volume fractions and under conditions such that no δ-phase particles were present. In situ annealing treatments carried out to mimic pos...

Full description

Bibliographic Details
Main Authors: Meriem Zouari, Roland E. Logé, Nathalie Bozzolo
Format: Article
Language:English
Published: MDPI AG 2017-11-01
Series:Metals
Subjects:
Online Access:https://www.mdpi.com/2075-4701/7/11/476
Description
Summary:Microstructure evolution within the post-dynamic regime following hot deformation was investigated in Inconel 718 samples with different dynamically recrystallized volume fractions and under conditions such that no δ-phase particles were present. In situ annealing treatments carried out to mimic post-dynamic conditions inside the Scanning Electron Microscope (SEM) chamber suggest the occurrence of both metadynamic and static recrystallization mechanisms. Static recrystallization was observed in addition to metadynamic recrystallization, only when the initial dynamically recrystallized volume fraction was very small. The initial volume fraction of dynamically recrystallized grains appears to be decisive for subsequent microstructural evolution mechanisms and kinetics. In addition, the formation of annealing twins is observed along with the growth of recrystallized grains, but then the twin density decreases as the material enters the capillarity-driven grain growth regime.
ISSN:2075-4701