Electrical resistometry of Mg-based microcrystalline alloys and Mg-based composites

Specimens of the microcrystalline commercial alloy WE 54 were prepared by gas atomization and by following extrusion at 250°C or 400°C. Their thermal stability was studied by isochronal annealing from room temperature up to 500°C by means of electrical resistivity and microhardness measurements. The results were compared to the results obtained on conventionally prepared WE 54 alloy and explained by precipitation effects. Specimens of the commercial alloy QE 22 and cp-Mg were reinforced by 22 vol% Saffil short fibres, exposed to the normalization heat treatment T4 and isochronally annealed up to 300°C. The annealing response of electrical resistivity was measured and compared to the annealing response of non-reinforced materials. The results show only a slight influence of strengthening fibres on precipitation processes in QE 22 alloy.