Discrimination of dynamically and post-dynamically recrystallized grains based on EBSD data: application to Inconel...

Area of Science:

• Materials Science
• Metallurgy
• Crystallography

Background:

• Electron Backscatter Diffraction (EBSD) is a key technique for studying recrystallization.
• Conventional EBSD struggles to differentiate between dynamic and post-dynamic recrystallized grains due to subtle dislocation content variations.

Purpose of the Study:

• To investigate the impact of angular resolution on EBSD analysis for Inconel 718.
• To demonstrate methods for improving EBSD angular resolution to distinguish recrystallized grain populations.

Main Methods:

• Utilizing advanced Kikuchi pattern indexing and the Local Linear Automatic Smoothing Splines (LLASS) denoising filter to enhance EBSD angular resolution.
• Performing EBSD analyses on Inconel 718 samples with varying dislocation densities.
• Employing Electron Channeling Contrast Imaging (ECCI) for complementary analysis.

Main Results:

• Improved EBSD angular resolution (0.1-0.2°) successfully distinguished between dynamically and post-dynamically recrystallized grains.
• Quantified the coexistence of these two grain types within the Inconel 718 sample.
• ECCI confirmed EBSD findings and revealed thermal stress-induced dislocations.

Conclusions:

• Enhanced angular resolution in EBSD is critical for accurately characterizing recrystallization mechanisms.
• The study confirms the presence of both dynamic and post-dynamic recrystallization in Inconel 718.
• Improved EBSD techniques offer greater insight into microstructural evolution in superalloys.