Synergistic Thermal and Electron Wind Force-Assisted Annealing for Extremely High-Density Defect Mitigation

Area of Science:

• Materials Science
• Metallurgy
• Condensed Matter Physics

Background:

• Cold rolling introduces high-density dislocation networks, forming low-angle grain boundaries in FeCrAl alloys.
• Residual stress and defects from deformation hinder alloy performance.

Purpose of the Study:

• To investigate the efficacy of combined thermal and athermal stimuli for annealing FeCrAl alloys.
• To compare this novel annealing method with conventional thermal annealing.

Main Methods:

• Utilized electron wind force (athermal stimulus) via high current density pulses.
• Applied combined stimuli with varying average temperatures (100°C, 200°C) and current densities.
• Analyzed defect structures using electron and X-ray diffraction.

Main Results:

• Electron wind force alone did not anneal defects in 25% reduced specimens.
• Combined stimuli at 100°C and 3300 A/mm² annealed 25% reduced specimens in 1 minute.
• Combined stimuli at 200°C and 700 A/mm² effectively annealed 50% reduced specimens (85% low-angle grain boundaries).
• This method is significantly faster and requires lower temperatures than conventional annealing (750°C, 1.5h).

Conclusions:

• Combined thermal and athermal stimuli offer a highly effective annealing method for FeCrAl alloys with extreme defect densities.
• This technique provides a substantial improvement over conventional annealing, reducing time and temperature requirements.