Dynamic recrystallization behavior of magnesium alloys with LPSO during hot deformation

摘要

The hot deformation and dynamic recrystallization behaviors of as-homogenized Mg-12Gd-4.5Y-2Zn-0.4Zr alloy were investigated through compression tests in this paper. This work presents the appropriate deformation zone. Different degrees of discontinuous dynamic recrystallization occurred in the alloys under different strain rates and temperatures. The critical strain prediction model of these alloys during hot deformation was obtained through calculation of work hardening rate, inflection points in the In theta - epsilon curves and the minimum value of the -(partial derivative(In theta)/partial derivative epsilon) - epsilon curves. At lower strain rates and temperatures, kink band deformations constitute an essential mechanism for homogeneous strain creation. As the strain rate increased, the kink band deformations became significantly serious, the new kinks were formed within the former kink bands, leading to grain refinement. In addition, a low amount. of discontinuous dynamic recrystallizations occurred. As the strain rate increased, the volume fraction of discontinuous dynamic recrystallization was increased, whereas the kink band deformation decreased. (C) 2017 Elsevier B.V. All rights reserved.