High Temperature Tensile Strength of TI6AL4V Processed by L-PBF—Influence of Microstructure and Heat Treatment

Abstract

Ti6Al4V is the most widely used α‑β Titanium alloy for application in medicine, automotive, and aerospace, known for its high strength and corrosion resistance, but also its high maximal operating temperature of around 420 °C. Combined with its decent weldability under a shield atmosphere it has become a standard alloy for additive manufacturing processes, especially laser and electron beam powder bed fusion (L-PBF). Although this material is well studied, the influence of the L‑PBF process on its tensile properties at elevated temperatures remains almost unexplored. For that reason, this contribution focuses on the analysis of the tensile properties of Ti6Al4V up to 500 °C for different heat treatments and compares it to aerospace standards.Furnace annealed samples reach a tensile strength between 1022 to 660 MPa from room temperature to 500 °C respectively, while stress-relieved specimens reach 1205 to 756 MPa. Stress-relieved samples show a lower ductility at room temperature, but elongation at break increases at high temperature and outperforms furnace annealed samples at 500 °C.