Tensile deformation characteristics of a nano-structured 5083 Al alloy

The microstructure and tensile deformation characteristics in the commercial 5083 Al alloy after equal channel angular pressing (ECAP) at 373 and 473 K were investigated and compared with those of one reannealed at 473 K for 1 h after ECAP at 373 K. All specimens revealed nano-structure with grains of ∼300 nm and no distinct grain boundaries except the reannealed alloy. The strength in the alloy pressed at 373 K was much higher than that of as-received alloy but the elongation to failure was significantly smaller, while, in case of pressing at 473 K, the improvement in strength was found concurrent with slight work hardening, without sacrificing much of the elongation. The tensile properties of the reannealed alloy were in between those of ones pressed at 373 and 473 K. These tensile deformation characteristics were analyzed based on the observations of deformed microstructure and fracture surface by TEM and FE-SEM, respectively.