Microstructure, texture, and mechanical properties of multi-pass cold drawn Mg–xZn alloy wire

Abstract

We performed multiple-pass cold drawing for Mg-4.0 wt%Zn (Z4) and Mg-6.0 wt%Zn (Z6) which showed a preferable drawing deformability of ∼76 and 69 % accumulative true strain (ATS), respectively, at room temperature. Zn addition into pure Mg caused the microstructure refinement and the strengthening of Mg alloy, while the ductility of Mg alloys decreased with increasing Zn content. Moreover, the microstructure of as-drawn Z4 wire with larger ATS showed fibrous morphology, and the grains were elongated along the drawing direction (DD) but the grain boundaries could still be distinguished in wires of Z6 alloy. Based on texture analysis, the non-basal texture of Z4 and Z6 gradually increased with cold drawing. Eventually, the texture component of both Z4 and Z6 wires transformed from as-extruded basal texture to obvious fiber texture with parallel to the DD. The difference was that, besides the formation of a main basal texture, a weaker non-basal texture also appeared in as-extruded Z6 alloy with a higher Zn content. The addition of Zn promoted the formation of non-basal texture.

Keywords

• Mg-Zn alloy
• Cold drawing
• Texture
• Microstructure