Enhanced mechanical properties of near-α Ti60 alloy by laser powder bed fusion

The near-α Ti60 alloy, renowned for its exceptional high-temperature performance, is highly sought after for aerospace applications. This study optimized the laser powder bed fusion (LPBF) parameters to fabricate Ti60 alloy with a density approaching 99.84 %. The rapid solidification process inherent to LPBF results in an ultrafine martensitic microstructure within the Ti60 alloy, characterized by the presence of intricate α′ martensite laths within the β columnar grains. The alloy's crystallographic structure is distinguished by a high density of dislocations and twins, which significantly augment its mechanical properties at both ambient and elevated temperatures. At room temperature, the alloy exhibits a tensile strength of 1402 MPa coupled with a elongation of 12.3 %. At 600 °C, these values increase to 686 MPa and 25.6 % elongation, respectively. These findings have the potential to significantly advance the application of LPBF-ed Ti60 alloy in the aerospace sector, while also offering a pivotal reference for the additive manufacturing of other high-performance titanium alloys.