Isothermal section of Mg–Nd–Gd ternary system at 723 K

An isothermal section of the Mg–Nd–Gd ternary system at 723 K was established by diffusion triple technique and electron probe microanalysis (EPMA). Mg3Gd and Mg3Nd form a continuous solid solution (Gd, Nd)3Mg, and a continuous solid solution (Gd, Nd)Mg is also formed between MgGd and MgNd. Mg7Gd, Mg5Gd, Mg2Gd, Mg41Nd5, (Gd, Nd)3Mg and (Gd, Nd)Mg are found in the ternary system. In these intermetallic phases, Mg7Gd has been reported to be a metastable phase in previous literatures. The solubilities of Mg, Gd and Nd in all the phases were detected. Furthermore, four three-phase equilibria, α(Mg)+Mg7Gd+ Mg41Nd5, Mg7Gd+Mg5Gd+Mg41Nd5, Mg5Gd+Mg41Nd5+(Gd, Nd)3Mg and (Gd, Nd)3Mg+(Gd, Nd)Mg+Mg2Gd, were identified in the isothermal section.