THE EFFECT OF MAGNESIUM CONTENT ON MICROSTRUCTURE EVOLUTION DURING HOT DEFORMATION OF ALUMINUM ALLOYS

摘要

Aluminum alloy specimens were tested in tensionand compression at temperatures up to 500 °C and strain rates upto 1.0 s~(-1) to study the microstructures developed during hotworking. An AA5182 alloy was hot deformed in tension andsubsequently annealed to promote recrystallization, while two Al-Mg alloys (Al-0.5Mg, Al-4.5Mg) were hot deformed incompression and examined as-quenched. The AA5182 alloyshowed no signs of dynamic recrystallization, but experiencedincreased static recrystallization with increasing tensile strainduring subsequent annealing. Annealing also resulted in staticabnormal grain growth (SAGG) for the AA5182 in regions oflight to moderate strain. The Al-4.5Mg alloy, which was tested atfaster strain rates and in compression, showed signs of geometricdynamic recrystallization (GDRX) during deformation, while theAl-0.5Mg alloy did not show any signs of recrystallization underthe same conditions. Results indicate that increased Mgconcentration enhances GDRX and increases SAGG followinghot deformation.