Investigation of the hardening behavior during recrystallization annealing in Al-Mg-Sc alloy

Abstract In this work, Al-3Mg-0.2Sc alloy with a single pass friction stir processing (FSP) was cold rolled, followed by recrystallization annealing. Hardening behavior was observed in cold rolled alloy after annealing treatment at 330 °C and 400 °C. The hardening phenomenon can be rationalized by a calculation between the Zener pinning (PZ) and the driving force of recrystallization ( P D R e x ). The result of contrastive calculation accords with the hardness change in the early stage of annealing, while the characteristics about coherency of Al3Sc particles determine that the contrastive calculation is inapplicable to later period of annealing. Specifically, the destruction of coherency between Al3Sc particles and matrix after annealing time exceeds 75 min makes that the actual value of PZ is much less than the predicted value of calculation.