Novel partially biodegradable Ti-6Al-4V/Zn composites fabricated through hybrid additive manufacturing and powder metallurgy

This study reports the development of a Ti6Al4V-Zn metallic bi-metal composite (Ti64-Zn MBMC) engineered for biodegradable biomedical applications. The composite features a continuous additively manufactured (AM) Ti64 hexagonal lattice that provides a three-dimensional structural framework, while Zn infiltrates and occupies the interconnected pore network. Fabrication was achieved through a hybrid route combining AM and powder metallurgy, wherein the Ti64 lattice was first produced by AM, followed by Zn incorporation and consolidation via spark plasma sintering. The tomography results reveal that the composite consists of approximately 27% Ti64 reinforcement phase and 73% Zn matrix phase, confirming successful introduction of Zn within the architected Ti64 honeycomb scaffold. Microstructural characterization confirmed a crack-free interface with no detectable interfacial reactions between Ti64 and Zn. The Ti64-Zn MBMC exhibited a compressive strength of 292±25 MPa, surpassing that of both pure Zn and the Ti64 lattice. Potentiodynamic polarization in simulated body fluid (SBF) revealed corrosion behavior comparable to pure Zn, with post-corrosion microscopy showing selective dissolution of Zn while Ti64 struts remained intact. In-vitro biodegradation tests indicated an initial degradation rate of 0.1577 mm/year in SBF. Cytocompatibility assessments using MC3T3-E1 pre-osteoblasts demonstrated healthy cell proliferation in media conditioned with composite leachates. Collectively, these results establish the Ti64-Zn MBMC as a promising candidate for next-generation biodegradable implants and tissue-engineering scaffolds. • Employ hybrid fabrication strategy combining additive manufacturing and powder metallurgy. • Fabricate bio-inspired architecture for partially biodegradable implants. • Controlled degradation of implants by galvanic interactions. • Material with healthy cell proliferation and no cytotoxic effects.