Enhanced oxidation resistance of a titanium–based alloy by the addition of boron and the application of electron beam melting

Refined TiB precipitates significantly enhance the oxidation resistance of Ti-6Al-2Sn-4Zr-2Mo-0.1Si-1.0B alloy fabricated by electron beam powder bed fusion (EB-PBF). Refined TiB precipitates in the EB-PBF-built alloy enable finer oxide formation than the larger precipitates in the forged alloy, and the resulting oxidation layers are more compact. Evaporation of scattered B2O3 generated by the refined TiB precipitates in the EB-PBF-built alloy do not significantly accelerate detachment of the oxidation layer from the substrate. However, collective evaporation of B2O3 generated by larger TiB precipitates in the forged alloy accelerate detachment. The oxidation layer on the EB-PBF-fabricated alloy was more stable, preventing further oxidation and improving oxidation resistance.