Interpenetrating phases composites Ti6Al4V/Zn as partially degradable biomaterials to improve bone-implant properties

Abstract

Ti6Al4V is a commonly used metal for implants in clinical practice. While Ti6Al4V scaffolds offer adjustable mechanical properties, they are prone to causing infections post-implantation due to their lack of antibacterial properties. On the other hand, Zn is a promising degradable medical metal with antibacterial capabilities, but falls short in meeting the mechanical requirements for implants and has a slow degradation rate. In this paper, the Ti6Al4V scaffold was fabricated using laser-based powder bed fusion (PBF-LB), then immersed in molten Zn while utilizing an oxide film to prevent merging of the two materials. This resulted in the development of an interpenetrating phase composites (IPCs) combining Ti6Al4V and Zn, effectively leveraging the strengths of both materials to enhance implant performance in bone repair applications. The fabrication of Ti6Al4V/Zn IPCs not only imparts excellent antibacterial properties to the implant, but also improves stress transfer within the Ti6Al4V scaffold during deformation, preventing local collapse and optimizing mechanical properties. The Ti6Al4V scaffold provides mechanical support throughout the degradation of Zn, while the galvanic corrosion effect accelerates Zn degradation. These IPCs exhibit mechanical and biological properties essential for implants, offering a novel approach to integrating mechanical and antibacterial properties in bone-implant materials. This technique can be applied to create multifunctional integrated materials in various engineering and manufacturing sectors beyond just bone implants.