Investigation on mechanical anisotropy of strip cast (SC) aluminum alloy AA5182

Mechanical anisotropy between the rolling direction (RD), 45degrees from the rolling direction (QD) and the transverse direction (TD) has been studied in both strip cast (SC) and direct chill (DC) cast AA 5182 alloy with regard to the tensile yield strength (YS) as well as the Portevin-Le Chatelier (PLC) effect. A material with tensile strength anisotropy also exhibits anisotropy of serration intensity (Deltasigma). A material without tensile strength anisotropy also does not possess serration intensity anisotropy. The anisotropic behavior of mechanical properties is associated with the microstructure of the materials. Materials with a rolling structure (i.e., SC hot band) exhibit an apparent mechanical anisotropy (YS and Deltasigma). The YS in the RD and the TD are very close and both are higher than in the QD while the serration intensity (Deltasigma) is largest in the TD, smallest in the RD with the QD in between but closer to the TD. However, no such mechanical anisotropy was observed in fully recrystallized materials (i.e., DC hot band and annealed SC hot band). The mechanical anisotropy is ascribed to the combination of elongated grains and the anisotropic distribution of microstructures, i.e. precipitates, dislocations, and solute atoms.