Superplastic Behaviour of AA5083 Aluminium Alloy with Scandium and Zirconium

The aim of the present investigation was to determine and to compare the superplastic behaviour of the AA5083 (Al-Mg-Mn) alloy with Sc and Zr additions. The investigated alloys were processed to form sheets by conventional hot and cold rolling. The superplastic properties were determined with strain rates in the range of 1x10(-4) to 5x10(-2)s(-1) and forming temperatures of 350 to 550 degrees C. The results showed that the alloy with about 0.4% Sc exhibited a high superplastic ductility across a wide temperature range and strain rates up to 1x10(-2)s(-1). The highest elongations to failure of about 2000% were attained at 550 degrees C and at an initial strain rate of 5x10(-3)s(-1). However, the alloy with about 0.15% Zr exhibited elongations up to 600%. The FSP processed Al-4.5Mg alloy with combined addition of about 0.2% Sc and 0.15% Zr exhibited good superplastic properties at higher strain rates (> 1x10(-2)s(-1)) with elongations up to 1500%.