Superplasticity of Mg-Gd-Y alloy in tensile test at
elevated temperature
elevated temperature
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: The high tensile ductility of Mg-Gd-Y alloy at temperatures above 623 K and average engineering strain rate of 4.6×10−4 s−1 was investigated. The results show that the high ductility (elongation 77%) at 623 K is attributed to the basal, non-basal dislocations glides. The superplasticity deformation (elongation 180%) at 673 K includes three stages. The first stage is the plastic deformation induced by dislocation gliding and twining. The second stage is the grain refinement controlled by dynamic recrystallization. The third stage includes two processes of the fine grain growth and grain refinement of the elongated grain with high stored energy.
Key words: Mg-Gd-Y; ductility; superplasticity; microstructure