Rapid hardening induced by electric pulse annealing in nanostructured pure aluminum

Nanostructured pure aluminum was fabricated by heavy cold-rolling and then subjected to recovery annealing either by applying electric pulse annealing or by traditional air furnace annealing. Both annealing treatments resulted in an increase in yield strength due to the occurrence of a “dislocation source-limited hardening” mechanism.

However, the hardening kinetics was substantially faster for the electric pulse annealed material. Detailed microstructural characterization suggested that the rapid hardening during electric pulse annealing is related to an enhanced rate of recovery of dislocation structures.