Binder Jetting of Ti-6Al-4V Alloy: The Effect of Thermal Debinding

Binder jetting, a sinter-based additive manufacturing method, provides a cost-effective route for producing complex-shaped parts from high-value materials such as titanium alloys for biomedical application. However, maintaining C and O content below the required levels for biomedical applications remains a significant challenge. In this context, thermal debinding is a critical post-processing step as it governs the removal of organic binders and directly influences the attainment of carbon and oxygen levels compliant with ASTM standards for surgical implants. In this study, the effects of debinding parameters—temperature, dwell time, and atmosphere—on microstructure, impurity uptake and mechanical properties of Ti-6Al-4V components produced via binder jetting were systematically investigated. The highest mechanical performance, with a tensile strength of ~ 860 MPa, elongation of ~ 7%, and porosity of ~ 7%, was achieved in samples subjected to a double debinding cycle: hydrogen at 350 °C followed by argon at 550 °C. In contrast, high-temperature debinding in hydrogen (550-650 °C) caused rapid binder evaporation, leading to large pore formation reducing strength and ductility. Although hydrogen atmospheres and multistep debinding improved mechanical properties and mitigated impurities uptake in Ti-6Al-4V components, the final carbon and oxygen levels still exceed ASTM specifications for biomedical-grade Ti-6Al-4V. Further optimization, such as the development of catalytic debinding strategies and novel low-residue binder formulations, will be required to minimize interstitial contamination and unlock the full potential of binder jetting for titanium alloy biomedical components.