Effect of aging treatment on phase evolution and mechanical properties of selective laser melted Al-Mg-Er-Zr alloy

Er and Zr modified Al-Mg alloy was manufactured by selective laser melting. The effect of aging treatment on phase evolution and mechanical properties of alloy has been studied. The results show that bimodal grain structures (2.8 +/- 1.1 mu m) could be obtained, thanks to the Al3Zr primary phases promoting the formation of equiaxed grains (0.8 +/- 0.3 mu m) at the boundary of molten pool. During the aging of 375 degrees C, Al3(Er,Zr) particles with the size of 2-5 nm were produced via synergistic precipitation of Er and Zr, which would greatly improve the strength and reach 510 +/- 9 MPa. At the same time, the Mg-rich phase was dissolved, the Mn-rich phase was precipitated, and dislocations could accelerate the diffusion of solute atoms during the evolution of the phases.

Automated summary

The Er and Zr modified Al-Mg alloy manufactured by selective laser melting showed improved mechanical properties and strength after aging treatment. The synergistic precipitation of Er and Zr led to the formation of bimodal grain structures, promoting phase evolution in the alloy.