Relationships between build rate and mechanical properties in Ti-6- Al-4V WAAM

Abstract

Wire + Arc Additive Manufacture (WAAM) is a process for building metallic components in a layer-by-layer manner. This process presents has high potential to reduce manufacturing cost and lead-time for large critical components. Its use at low deposition rates and heat inputs might produce smaller features with higher degree of accuracy. Until now, no experimental data have been reported for deposition rates lower than 0.5 kg/h for the Ti64 alloy deposited by WAAM. This project focussed on deposition rates between 0.1 and 0.4 kg/h coupled to changes in thermal conditions. The main outcome was that the reduction of heat input has an impact on the microstructure decreasing both the α lamellae and the prior β grain size. This might result in improved strength and higher hardness. Furthermore, deposits as thin as 3 mm could be produced with the lowest heat input values, which confirmed the potential for production of features with higher resolution, thus enabling further cost savings.