Microstructure and mechanical properties of Ti2AlNb alloys manufactured by LPBF and HIP post-treatment

This study investigates effects of laser powder bed fusion (LPBF) parameters and hot isostatic pressing (HIP) on microstructure and mechanical properties of Ti2AlNb alloy. Through parameter optimization with 315 W laser power and 1100 mm/s scanning speed, Ti2AlNb exhibited an ultimate tensile strength (UTS) of 1060 MPa and an elongation (EL) of 19.85%, far surpassing the level of traditional casting and forging. Ductility of Ti2AlNb with low volume energy densities (VED) was affected by defect size and distribution, while those with high VED may experience embrittlement due to thermal stress accumulation. Although HIP eliminated defects and increased UTS to 1168 MPa, it induced grain coarsening to 187.7 μm. Multiple coarse needle-like O and α2 phases caused a sharp drop in EL to 1%.