Diffusion behaviors and mechanical properties of binary Mg-Ce system

In this work, the solid-solid diffusion reaction and growth kinetics of the Mg-Ce system was investigated by diffusion coupling technique. Four intermetallic compounds Mg12Ce, Mg41Ce5, Mg3Ce, MgCe and one solid so-lution phase & delta;Ce were observed in the diffusion zone with the annealing temperature range of 673-823 K. The results shown that the growth process in the diffusion area was dominated by bulk diffusion. The growth con-stants, integrated diffusion coefficients, growth activation energies and diffusion activation energies of the four intermetallics were calculated based on the thickness of the phases, reaction temperature and annealing time. Mg3Ce has the largest diffusion activation energy. The mechanical properties of the four IMCs were investigated by using nanoindentation characterization technology and first-principles calculations. The nanoindentation tests show that the Mg12Ce phase possessed the largest Young's modulus (66.08 GPa) and hardness (2.14 GPa). The experimental results are consistent with the trend of the calculated results. The obtained diffusion kinetical properties and mechanical properties of the Mg-Ce system provide useful data for the development of new magnesium-rare earth alloys.

Automated summary

The solid-solid diffusion reaction and growth kinetics of the Mg-Ce system were investigated using diffusion coupling technique. Four intermetallic compounds (Mg12Ce, Mg41Ce5, Mg3Ce, MgCe) and one solid solution phase (δCe) were observed in the diffusion zone at temperatures ranging from 673 K to 823 K. The growth process in the diffusion area was mainly controlled by bulk diffusion. The diffusion activation energy of Mg3Ce was found to be the highest among the intermetallic compounds. The mechanical properties of the intermetallic compounds were characterized using nanoindentation and first-principles calculations, showing that Mg12Ce had the highest Young's modulus (66.08 GPa) and hardness (2.14 GPa). The obtained diffusion kinetic properties and mechanical properties of the Mg-Ce system provide valuable data for the development of new magnesium-rare earth alloys.