The microstructure and mechanical properties of magnesium-gadolinium a
nd magnesium-gadolinium-yttrium alloys have been studied. There are ex
tended magnesium solid solution areas in the systems narrowing as temp
erature lowers. The decomposition of the magnesium supersaturated soli
d solutions results in significant strengthening of the alloys. The al
loys have good mechanical properties at room and elevated temperatures
combined with low density.