Design of novel Zn-Ag-Zr alloy with enhanced strength as a potential biodegradable implant material

In this study, a new biodegradable alloy from the Zn-Ag-Zr system was investigated. Most importantly, mechanical properties and ductility were significantly improved in designed Zn1Ag0.05Zr alloy in comparison to binary Zn1Ag and previously investigated Zn0.05Zr alloys (wt%). The characterized alloy reached values of yield strength, ultimate tensile strength and elongation to failure equal to 166 +/- 2 MPa, 211 +/- 1 MPa and 35 +/- 1%, respectively. Simultaneous addition of both alloying elements contributed to solid solution strengthening, intermetallic Zr-rich phase formation, and effective grain refinement. Immersion and electrochemical in vitro corrosion tests showed a slight increase of degradation rate in ternary alloy up to 17.1 +/- 1.0 mu m/year and no significant loss of mechanical properties after 28-day of immersion in simulated physiological solution. In addition, the preliminary antimicrobial studies show antimicrobial activity of the investigated Zn-Ag-Zr alloy against Escherichia coli and Staphylococcus aureus. The presented results demonstrate that newly developed Zn-based alloy can be considered as a promising biodegradable material for medical applications. (C) 2019 The Authors. Published by Elsevier Ltd.