High strength, ductility and superplasticity Mg-6Zn-1Y-0.6Ce-0.6Zr alloy prepared by rapid solidification and reciprocating extrusion

Abstract

High strength, ductility, and superplasticity Mg-6.0%Zn-1.0%Y-0.6%Ce-0.6%Zr (wt%) alloy was prepared by sequentially applying rapid solidification, extrusion, and reciprocating extrusion (REX). The microstructure of the alloy after 2-pass REX consisted of fine grains smaller than 0.7 μm and nanometer strengthening particles. The refined grains resulted from recrystallization during which the nanometer particles played an important role in restrain grain growth. The mechanical properties of the material were investigated at room and elevated temperatures. High tensile yield strength of 336 MPa and elongation of 27% were obtained at room temperature. At elevated temperatures, the highest elongation of 270% was obtained at 250 °C and an initial strain rate of 3.3×10-3 s-1, and LTS and HSRS were achieved. The high strength, ductility, and superplasticity were attributed to the refined unique microstructure.