Microstructure, mechanical properties, and corrosion behavior of Zn-x wt.% Ti (x = 0, 0.3 and 1) alloys for biomedical applications
Hany R. Ammar, S. Sivasankaran, R. Karunanithi
Abstract
Zn-x wt.% Ti (x = 0, 0.3, and 1) alloys were developed using vacuum induction melting. The alloys were characterized using X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and electron backscatter diffraction (EBSD). XRD analysis revealed the formation of η-Zn-rich solid solution as the primary phase in all alloys, the addition of Ti promoting the formation of TiZn 16 intermetallic phases. Microstructural analysis revealed refined grain structures with increasing Ti content due to the grain-refining effect of Ti and the formation of fine TiZn 16 particles. Nanoindentation testing revealed that the addition of Ti significantly enhanced the mechanical properties of the alloys compared to pure Zn. The hardness of the Zn-0.3 wt% Ti alloy increased by 19.23 %, while the Zn-1 wt.% Ti alloy exhibited a 24 % increase in hardness compared to pure Zn. The elastic modulus of Zn-1 wt.% Ti improved by 80.6 % relative to pure Zn, indicating enhanced stiffness. The alloys' density displayed a marginal decrease with increasing Ti content due to titanium's lower atomic weight compared to zinc. Corrosion testing demonstrated that the addition of Ti significantly improved the corrosion resistance of the Zn–Ti alloys. The current density (I corr ) decreased, and the potential (E corr ) shifted towards more positive values with increasing Ti content. The Zn-1 wt.% Ti alloys exhibited a 27.6 % reduction in corrosion rates compared to pure Zn. A 7-day immersion test in Hanks' solution confirmed the long-term corrosion resistance where Zn-1 wt.% Ti revealed the lowest degradation rate and smoothest corroded surface. These findings demonstrate the potential of Zn–Ti alloys for applications in biomedical implants and advanced manufacturing sectors due to their enhanced mechanical and corrosion-resistant properties. • Zn–x wt.% Ti alloys were developed using vacuum induction melting for biodegradable implant applications. • The addition of Ti promoted TiZn 16 intermetallic phases, which enhanced microstructural uniformity. • Mechanical properties of Zn–1 wt.% Ti exhibited 24.3% increase in hardness and an 82.1% increase in elastic modulus. • Zn–1 wt.% Ti demonstrates 27.6% reduction in corrosion rate due to a protective Ti-rich oxide layer.