Characteristics of microstructural and mechanical evolution in 6111Al alloy containing Al3(Er,Zr) nanoprecipitates

The evolution of microstructure and mechanical performances in 6111Al matrix alloy affected by trace amount of Er and Zr elements was thoroughly explored in this research work. Nanosized Al-3(Er,Zr) particles with core shell or hybrid structure owned perfect coherent relation with matrix Al, which acted as effective sites for the heterogeneous nucleation of alpha-Al. The average grain size was significantly refined from 147 +/- 5 mu m to 53 +/- 2 mu m in 6111Al-0.3wt%Er-0.1wt%Zr alloy. Besides, the precipitation behavior of the initial Mg2Si strengthening phase was also enhanced by these Al-3(Er,Zr) dispersoids. Assisted by the cooperation of Grain refinement strengthening and Orowan strengthening etc., the yield strength, ultimate tensile strength and elongation of the alloy were high up to 289 MPa, 320 MPa and 12.9% respectively. A traditional hot rolling process has been conducted here to study the promotion and inhibition effect induced by Al3(Er,Zr) phases on recrystallization during deformation. The interaction among dislocations, grain boundaries and dispersoids was systematically and comprehensively revealed in this paper.

Automated summary

By introducing trace amounts of Er and Zr elements into the 6111Al matrix alloy, the microstructure was refined and the mechanical properties were improved significantly. The introduction of Al-3(Er,Zr) particles contributed to the nucleation of alpha-Al and enhanced the precipitation behavior of the strengthening phase. The alloy exhibited high yield strength, ultimate tensile strength, and elongation due to the combined effects of grain refinement strengthening and Orowan strengthening.