Microstructure, Mechanical Performance and Anti-Bacterial Activity of Degradable Zn-Cu-Ag Alloy
Tongxin Di, Ying Xu, Debao Liu, Xiaohao Sun
Abstract
Zn-based materials have attracted increasing attention in the biodegradable materials field due to their unique combination of suitable biodegradability and good biological functionalities. However, the currently existing Zn alloys exhibited poor mechanical reliability and insufficient anti-bacterial activity. In this study, the microstructure, mechanical properties, corrosion behavior and antibacterial properties of Zn-1Cu-0.5Ag and Zn-1Cu-1Ag alloys were investigated. The average grain size of the alloys decreased from 1.91 μm in the Zn-1Cu-0.5Ag alloy to 1.64 μm in the Zn-1Cu-1Ag alloy with the increasing Ag concentration. Due to the grain refinement effect, Zn-1Cu-1Ag exhibited higher ductility (elongation of 36.0%) compared with its Zn-1Cu-0.5Ag counterparts (elongation of 26.3%). In the meantime, the Zn-1Cu-1Ag alloy possessed the ultimate tensile strength (UTS) of 292.04 MPa, the yield strength (YS) of 269.49 MPa, and the Vickers hardness value of 96.9. The anti-bacterial properties of the material were evaluated by the inhibition zone test. The addition of Cu and Ag endowed strong anti-bacterial activity to staphylococcus aureus (S. aureus) and escherichia coli (E. coli) with the zinc matrix. The Zn-1Cu-1Ag alloy exhibited improved mechanical properties, a moderate degradation rate of 0.0484 mm/y, acceptable cytocompatibility, and efficient anti-bacterial properties which should be useful for orthopedic applications.