Strain-rate dependence of mechanical properties in AA5056 Al–Mg alloy processed by equal-channel-angular-extrusion

Microstructure of AA5056 Al–Mg alloy is refined dramatically by the equal-channel-angular-extrusion (ECAE) process. Tensile properties at room temperature in the ECAE-processed 5056 Al–Mg alloy (5056-ECAE) are characterized as a function of strain rate. Total elongation of 5056-ECAE increases with strain rate in the same way as some fully annealed Al–Mg alloys, and the result supports the possibility of using the alloy for high-rate forming. Yield stress (YS) and ultimate tensile strength (UTS) in 5056-ECAE exhibit remarkably higher values than those of the fully annealed 5056 alloy (5056-O). UTS of 5056-ECAE is almost independent of strain rate below the strain rate of 6.5×102 s−1, compared with 5056-O. Change in the strain rate sensitivity of UTS may be caused by the difference in the interaction between solute atoms and dislocations.