Study of the decomposition of the magnesium-based solid solutions in Mg-Sm-Tb alloys

Abstract

Kinetics and structural transformations upon the decomposition of a magnesium-based supersaturated solid solution in Mg-Sm-Tb alloys have been studied at various relations between the concentrations of terbium and samarium. It has been established that with increasing terbium content in the alloys the strengthening upon the decomposition of the supersaturated magnesium-based solid solution increases. The decomposition of the supersaturated magnesium-based solid solution in the Mg-Sm-Tb alloys with a percentage ratio (wt %) Tb: Sm of about 2.5 exhibits signs characteristic of the decomposition of the supersaturated solid solution in binary Mg-Tb alloys. With allowance for the equilibrium Mg-Sm-Tb phase diagram, this gives grounds to suppose that samarium is mainly dissolved in the products of the decomposition of the magnesium solid solution that are characteristic of Mg-Tb alloys.