Properties and microstructure of twin-roll cast Al-Mg alloy containing Sc and Zr

Abstract

The influence of Sc and Zr on microhardness and microstructure of twin-roll cast Al-Mg alloy was studied. A significant effect of Sc and Zr on hardening of the material after annealing in a temperature interval between 250 C-omicron and 400 C-omicron was confirmed.

Maximal hardness was obtained after annealing above 300 C-omicron due to a precipitation of a fine dispersion of Sc and Zr containing precipitates. An exposure of the annealed material to higher temperatures suppresses the influence of these particles due to changes of the strengthening effect of precipitates.

However, a partially positive role of remaining precipitates hindering recrystallization persists even up to 550 C-omicron.

Keywords

• electrical-resistivity measurements
• annealed mold-cast
• exfoliation corrosion
• mechanical-properties
• heat-treatment
• precipitation
• scandium