Intermetallics and phase relations of Mg-Zn-Ce alloys at 400 °C

Abstract

The crystal structures, compositions and phase relations of the intermetallics of Mg-Zn-Ce system in the Mg-rich corner at 400 °C were identified through equilibrium alloy method. For Mg-Zn-Ce system, there is a linear ternary compound (T phase), whose chemical formula is (Mg1-xZnx)11Ce. The range of Zn content in T phase is from 9.6% to 43.6% (molar fraction). The crystal structure of T phase is C-centered orthorhombic lattice with lattice parameters of a=0.96-1.029 nm, b=1.115-1.204 nm, c=0.940-1.015 nm. And the lattice parameters of T phase are decreasing a little with increasing Zn content. According to the results of composition and crystal structure, the maximal solubility of Zn in Mg12Ce is about 7.8% (molar fraction), and the chemical formula of the solid solution can be identified as (Mg1-xZnx)12Ce. The isothermal section of Mg-Zn-Ce system in Mg-rich corner at 400 °C was constructed.