Improved ductility of Mg–3Gd–0.6Zr alloy by cuboid-shaped phase: experiments and first-principle calculations

Abstract

A casting Mg–3Gd–0.6Zr alloy was designed to evaluate the effect of cuboid-shaped phase on its mechanical properties. The morphology of cuboid-shaped phase was correlated with the directional covalent bonding between Gd atoms and H atoms along <100 > directions. The cuboid-shaped phase can be eliminated by a designed annealing treatment, without grain coarsening simultaneously. The ductility of as-cast alloy is about 20% higher than that of the annealed one. The improvement of ductility was caused by cuboid-shaped phase in three aspects: first-principle calculations, hydrogen embrittlement and crystal imperfections.

KEYWORDS:

• Magnesium alloys
• cuboid-shaped phase
• high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM)
• first-principle calculations
• ductility

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by Natural Science Foundation of Chongqing Science and Technology Commission, China (cstc2019jcyj–msxmX0601 and cstc2020jcyj–msxmX0069), Science and Technology Research Program of Chongqing Municipal Education Commission (KJQN201801312, KJQN202001303 and KJQN202101303) and Talent projects of Chongqing University of Arts and Sciences (2017RXC24).