Unraveling the strain-dependent Hall-Petch slope in low-to-high Mg content Al-Mg alloys

Experimental observations reveal that the formation of Laders bands and the Mg content significantly influence the strain dependence of the Hall-Petch slope in Al-Mg alloys containing varying Mg contents. Following macroscopic yielding, the Hall-Petch slope initially experiences a sudden drop due to Laders deformation, fol-lowed by an increase with plastic strain until it reaches its maximum value. Subsequently, it begins to decrease due to the occurrence of appreciable dynamic recovery. Alloys with higher Mg contents display a larger Hall-Petch slope at a given strain, and the onset of their appreciable dynamic recovery is substantially postponed until a larger strain is reached. Interestingly, we find that the relationship between the Hall-Petch slope, Mg content and strain magnitude can be accurately described by a model specifically developed for low stacking fault energy materials.