A review on the biomedical Ti-Cu alloys: Design, preparation, microstructure and properties

In clinical fields with a high risk of infection, such as orthopedics and dentistry, stringent requirements are imposed on the mechanical properties, biocompatibility, and antibacterial performance of biomedical materials. As an emerging functional biomedical alloy, Titanium-copper (Ti-Cu) alloys have received increasing attention due to their unique composition and microstructure, which endow these materials with favorable mechanical strength, biological activity, and long-lasting antibacterial functionality. However, a systematic summary of the existing research findings remains lacking. In this review, the classification and fundamental properties of Ti-Cu alloys are first outlined. Recent progress in design strategies, fabrication techniques, microstructural characteristics, mechanical behavior, wear resistance, corrosion performance, and biological properties is comprehensively reviewed. Special emphasis is placed on the dual forms of Cu (solid solution Cu and Ti 2 Cu phase) and their synergistic effects on both mechanical and biological performance. The antibacterial mechanisms and biosafety of Cu are specifically summarized, and its antibacterial efficacy and tissue compatibility are evaluated based on in vitro studies and animal models. Based on these findings, the key challenges associated with the practical application of Ti-Cu alloys are analyzed, and potential directions for optimization and future development are proposed. The review concludes with a concise summary and several forward-looking perspectives. • The two forms of Cu in Ti alloys and their synergistic mechanisms were systematically elucidated. • The processing-microstructure-properties relationship on Ti-Cu alloys is discussed. • The multiple antibacterial mechanisms of Ti-Cu alloys were clarified. • Multidisciplinary perspectives to guide future works on Ti-Cu alloys are discussed.