Two Al-Mg alloys plate with 0. 10wt% Sc and 0. 25wt% Er are prepared by casting-rolling-annealing
technology. The variation of tensile properties, corrosion properties and microstructure of the two alloys at different
treated condition was studied. The results show that the first, during annealing two alloys have same variation rule of
microstructure and properties, i. e. with the increase of annealing temperature, the strength decrease but the ductility
increase. At 350℃ /1 h annealing the alloy with 0. 10wt% Sc shows strong annealing softing-resistent ability, but the
alloy with Er become soft when the annealing temperature is higher than 280℃; at 300℃ /1 h annealing condition,
the tensile strength,yield strength and elongation of the alloy with 0. 10wt% Sc and 0. 25wt% Er are 424 MPa,314
MPa,18. 3% and 350 MPa,177 MPa,29. 1%, respectively. Meanwhile, the exfoliation corrosion resistance of the
two alloys show the same variation rule, i. e. at 200℃ /1 h annealing the exfoliation corrosion resistance of the two alloys
is the lest, then with increase of annealing temperature, the resistance increase. After 280℃ annealing for an
hour,two alloys can get excellent exfoliation corrosion resistance. Compared with 5B70 alloy, tensile properties, corrosion
properties and annealing softing-resistent ability of the alloy with 0. 25wt% Sc is similar to 5B70 alloy, but its
manufacture cost decreased, which shows good developing foresight on space vehicle.