Effect of Al addition on microstructure and mechanical properties of as-cast Mg-4Y-3Nd alloy

ABSTRACT

The microstructure and mechanical properties of Mg-4Y-3Nd-xAl (x = 0, 0.6, 0.9, 1.2, 1.5, 2.0%) alloys were investigated in the present work. The results show that the addition of Al can refine the grain of as-cast Mg-4Y-3Nd alloy significantly. The refining effect increases first and then decreases with increasing Al addition. The grain size of Mg-4Y-3Nd alloy is smallest when the Al addition is 1.5%. The reason for refinement is that the in-situ Al₂RE particles reacted Al with RE can serve as for α-Mg matrix. The orientation relationship between Al₂RE particles and α-Mg was determined by TEM analysis: $[101{]}_{\mathrm{A}{\mathrm{l}}_2\mathrm{R}\mathrm{E}}\parallel [1\overline{1}00{]}_{\mathrm{M}\mathrm{g}}{\left(\overline{2}22\right)}_{\mathrm{A}{\mathrm{l}}_2\mathrm{R}\mathrm{E}}\parallel (0002{)}_{\mathrm{M}\mathrm{g}}$. The effective size of Al₂RE particle served as heterogeneous nucleation site is 1 ∼12 μm. In addition, the strength and ductility of the alloy increase with the increase of Al addition. The Mg-4Y-3Nd-Al alloy with the higher mechanical properties can be attributed to fine grain strengthening and second phase strengthening.

KEYWORDS:

• Mg-Y-Nd alloy
• grain refinement
• Al₂RE particles
• mechanical properties

Acknowledgment

The authors gratefully acknowledge the financial support from the Heilongjiang Province Natural Science Foundation (No. E2018045).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Heilongjiang Province Natural Science Foundation: [Grant Number E2018045].