Review of additively manufactured zinc alloys by laser powder bed fusion for biomedical applications

Abstract

Zinc (Zn) and its alloys have emerged as promising candidates for biomedical materials, owing to their controlled degradation kinetics, intrinsic biocompatibility, and the release Zn²⁺ ions which are known to promote bone regeneration and tissue healing. Despite their potential, the widespread clinical adoption of Zn alloys has been hindered by insufficient mechanical properties, design limitations of traditional manufacturing, and limited clinical validation. Recent advances in additive manufacturing (AM), particularly laser powder bed fusion (LPBF), are revolutionizing the production of Zn alloy implants. LPBF enables unprecedented design freedom and accuracy, allowing the fabrication of patient-specific, geometrically-intricate and porous structures with unique functionality that are previously unattainable. This review aims to provide a comprehensive overview of the latest progress in LPBF processing of Zn alloys, focusing on structure design, fabrication, microstructural characteristics, and mechanical and biological properties—critical factors for real applications of functional implants, particularly in cardiovascular and orthopedic fields. Additionally, this review examines the role of post-processing treatments, such as heat treatments and surface modifications, in adjusting degradation rate, controlling Zn²⁺ ion release, and improving cell viability, proliferation and differentiation, all of which are vital for achieving predictable and reliable in vivo outcomes. Further, the review seeks to synthesize these advances and their interplays to provide a strategic insight for translating patient-specific, biodegradable Zn implants into clinical practice.

Graphical abstract