Diffusion behaviour and mechanical properties of binary Mg–Gd system

Abstract Diffusion behaviour of Mg–Gd intermetallic compounds (IMCs) were studied in the temperature range of 713–793 K using the diffusion couple method. Measured growth constants and integral interdiffusion coefficients of formed IMCs showed inverse-correlation to melting temperatures, excluding metastable phase Mg7Gd. Mechanical properties of obtained IMCs were studied using nanoindentation characterization technique and first-principles calculations. The experimental measured nano-hardness of Mg5Gd, Mg3Gd and Mg2Gd are 4.11 GPa, 4.05 GPa and 4.72 GPa, respectively, nearly twice of that of α (Mg). The obtained kinetic and mechanical information of Mg–Gd system is the basis for the development of high-strength Mg–Gd based Mg alloys.