Recent progress of novel biodegradable zinc alloys: from the perspective of strengthening and toughening

With a suitable degradation rate, fully bioresorbable degradation products, and excellent biocompatibility, Zn and its alloys are regarded as the most promising biodegradable metallic materials for clinical applications. However, their strength and ductility are generally below the mechanical benchmark for biodegradable implants, such as bone fixtures and stents, which restrict wider applications. Over the past decade, enormous efforts have been dedicated to improving the mechanical performance of Zn alloys, which greatly advance our understanding of Zn alloy development. This review highlights recent progress of biodegradable Zn alloys from the perspective of strengthening and toughening, with an emphasis on the relationship between the microstructure and the mechanical properties of the four major Zn alloy systems: Zn-Mg, Zn-Li, Zn-Mn, and Zn-Cu based alloys. The dominant mechanisms for high strength and high ductility of these alloys are elaborated. Finally, the future challenges and research directions of the field are outlined. This review strives for provide guidance for the future development of high-performance bioresorbable Zn alloys.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Zn and its alloys are considered as the most promising biodegradable metallic materials for clinical applications due to their suitable degradation rate, fully bioresorbable degradation products, and excellent biocompatibility. However, their strength and ductility are generally below the mechanical benchmark for biodegradable implants, limiting wider applications. Significant efforts have been made in the past decade to improve the mechanical performance of Zn alloys, advancing our understanding of Zn alloy development.