The Effect of Magnesium Content on Microstructure Evolution During Hot Deformation of Aluminum Alloys

Aluminum alloy specimens were tested in tension and compression at temperatures up to 500 °C and strain rates up to 1.0 s−1 to study the microstructures developed during hot working. An AA5182 alloy was hot deformed in tension and subsequently annealed to promote recrystallization, while two Al-Mg alloys (Al-0.5Mg, Al-4.5Mg) were hot deformed in compression and examined as-quenched. The AA5182 alloy showed no signs of dynamic recrystallization, but experienced increased static recrystallization with increasing tensile strain during subsequent annealing. Annealing also resulted in static abnormal grain growth (SAGG) for the AA5182 in regions of light to moderate strain. The Al-4.5Mg alloy, which was tested at faster strain rates and in compression, showed signs of geometric dynamic recrystallization (GDRX) during deformation, while the Al-0.5Mg alloy did not show any signs of recrystallization under the same conditions. Results indicate that increased Mg concentration enhances GDRX and increases SAGG following hot deformation.