A high-strength and high-ductility Zn–Ag alloy achieved through trace Mg addition and ECAP

Abstract

Zn–Ag alloys are promising biodegradable materials for clinical applications, but their mechanical properties are below the application requirements. In this work, a high-strength and high-ductility Zn–Ag alloy was achieved through trace (0.08 wt%) Mg addition and equal channel angular pressing (ECAP). Specifically, ECAP processed Zn-2.5Ag-0.08Mg alloy possesses a remarkably high ultimate tensile strength (UTS) and elongation (EL) of 393.1 MPa and 56.3%, respectively, far surpassing the application benchmark. The addition of Mg suppresses grain boundary sliding and thus delays the inverse Hall-Petch relation. The alloy features very fine grains of 1.23 μm, and grain boundary strengthening is the dominant strengthening mechanism. High-ductility is attributed to suppression of deformation twinning, activation of <c+a> pyramidal slip, and low dislocation density.