A bimodal grain structured Zn–0.5Ag–0.2Mg alloy with high strength and ductility achieved through combined ECAP and cold rolling

Abstract

Zn–Ag alloys are particularly promising for application as biodegradable implant materials due to their harmless degradation products, suitable degradation rate, and remarkable biocompatibility. Nonetheless, their mechanical properties are generally below the requirements for medical implants. In this work, a bimodal grain structured Zn–0.5Ag–0.2Mg alloy with excellent strength and ductility was achieved through combined equal channel angular pressing (ECAP) and cold rolling (CR), significantly superior to their counterparts obtained through ECAP or CR. Specifically, the ultimate tensile strength (UTS) and elongation (EL) of the alloy are as high as 332 MPa and 63%, respectively, far exceeding the application requirements. In achieving the excellent mechanical properties, a key role is played by hetero-deformation induced (HDI) strengthening. This work may provide practical guidance for developing high-performance Zn alloys.

Keywords

• Zn–Ag alloy
• Cold rolling
• ECAP
• Strength
• Ductility