Radiation Damage Mitigation in FeCrAl Alloy at Sub-Recrystallization Temperatures

Area of Science:

• Materials Science
• Nuclear Engineering
• Condensed Matter Physics

Background:

• Traditional annealing for defect recovery in FeCrAl alloys requires high temperatures (>750 °C).
• Irradiation-induced defects in materials can degrade performance and structural integrity.
• Lower-temperature defect mitigation strategies are crucial for advanced material applications.

Purpose of the Study:

• To investigate electron wind force (EWF)-assisted annealing as a low-temperature alternative for defect recovery in irradiated FeCrAl.
• To compare the efficacy of EWF annealing with traditional thermal annealing for mitigating irradiation damage.

Main Methods:

• FeCrAl samples were irradiated with 5 MeV Zr²⁺ ions to a dose of 10¹⁴ cm^-2.
• Electron wind force (EWF)-assisted annealing was performed at 250 °C for 60 seconds.
• Comparative traditional thermal annealing was conducted at 250 °C for 7 hours.
• Microstructural analysis included Kernel Average Misorientation (KAM) and low-angle grain boundaries (LAGBs) assessment.
• X-ray diffraction (XRD) was used to analyze full width at half maximum (FWHM) and peak position shifts.

Main Results:

• EWF annealing at 250 °C significantly reversed microstructural changes (reduced KAM and LAGBs) induced by irradiation.
• XRD analysis showed substantial reductions in FWHM and peak realignment, indicating effective stress and defect recovery.
• Traditional thermal annealing at 250 °C for 7 hours was less effective than EWF annealing, showing less pronounced XRD improvements.

Conclusions:

• Electron wind force (EWF)-assisted annealing is a highly effective low-temperature method for recovering irradiation-induced defects in FeCrAl.
• EWF annealing demonstrates superior efficiency compared to prolonged traditional thermal annealing at the same low temperature.
• This approach offers a promising pathway for enhancing the resilience of materials in radiation environments.