Oxidation difference of microstructural bands in additive manufactured titanium alloy

In this study, Ti6Al7Nb alloy produced by twin-wire arc additive manufacturing was oxidized at 800 degrees C to identify the oxidation difference induced by heat-affected bands (HABs), which have been widely reported in additive manufactured titanium alloys. The oxidation kinetics proved that HABs with compact beta laths have stronger oxidation resistance compared with that of the non-HAB zone. Nb element enriched in beta phase promoted Ti3Al to precipitate at the original position of beta laths after oxidation, having a similar spacing to the beta laths. The formation of compact Ti3Al on HAB beneficially inhibits oxygen diffusion across the oxide scale/matrix interface. IMPACT STATEMENT Oxidation difference induced by microstructural bands in additive manufactured titanium alloy was identified, and the stronger oxidation resistance of heat-affected bands was attributed to the more compact beta laths.

Automated summary

This study identified the oxidation difference induced by microstructural bands in additive manufactured titanium alloy. The stronger oxidation resistance of heat-affected bands is attributed to the more compact beta laths.