Superplastic Behavior of AZ31B Magnesium Alloy Processed by Equal Channel Angular Pressing (ECAP)

Abstract

AZ31B magnesium alloy with initial grain size of 11.2 µm was grain refined using Equal Channel Angular Pressing (ECAP) the alloy was ECAP-processed up to 5-times at 473 K. As a result, the grains are refined to 2.1 µm after three ECAP passes, the elongation was increased to 84 % at 473 K and strain rate of 1×10-4 s-1 after ECAP up to 5-passes,. Large fracture elongations of 261% are obtained at 623 K and strain rate 2.45×10-4 s-1 for specimen made from 3 ECAR passes compared to 183% for the as received material. Also the superplastic properties of the ECAP-processed specimens were investigated at 623 K and the strain rate ranges from 2.45×10-4 s-1 to 1.2×10-3 s-1. The strain rate sensitivity were determined to be 0.33