High temperature oxidation and embrittlement at 500–600 °C of Ti-6Al-4V alloy fabricated by Laser and Electron Beam Melting

•Similar oxidation kinetics for additively and conventionally manufactured Ti-6Al-4V.•Diffusion of oxygen in the metal is independent of metallurgical and surface states.•At 500 °C, weight gain is mainly due to oxygen ingress in the metal.•At 600 °C, weight gain is mainly due to oxide layer formation.•Oxygen concentration lower than 1 at. % induces brittle rupture. The oxidation kinetics of Ti-6Al-4V alloys fabricated by LBM and EBM, HIP-treated or not, are similar to that of a rolled annealed Ti-6Al-4V alloy, as regards oxide layer and oxygen diffusion layer thickness. Kinetics of oxygen ingress in the metal is independent of the alloy microstructure. At room temperature, the thickness of the brittle layer after a tensile test corresponds to the oxygen diffusion layer, with an oxygen concentration above a critical value that is clearly below 1 at %.