Dislocation configurations and stacking fault width in pure aluminum at ambient temperature: Insights from analytical calculations and HRTEM observations

This study presents an analysis of dislocation structures and stacking fault width (SFW) in pure aluminum, utilizing advanced analytical calculations alongside high-resolution transmission electron microscopy (HRTEM) to bridge gaps in current understanding. By incorporating key forces—line tension, image, and chemical forces—in the calculation of SFW, refined values of 9.43 Å for edge dislocations and 9.49 Å for screw dislocations are provided. Experimental observations using TEM and HRTEM identified various dislocation structures such as tangles, walls, and subgrain arrays, revealing a dynamic recovery process at strains as low as 0.1%. These dislocation structures, particularly aligned dislocations observed in IFFT images, suggest that pure aluminum’s high stacking fault energy allows easy slip, climb, and cross-slip of dislocations even under minimal cold work. The findings offer new insights into the microstructural behavior and stability of stacking faults in pure aluminum, highlighting the challenges of observing narrow stacking faults due to HRTEM’s resolution limitations.