A novel approach to achieving hybrid-manufactured Ti6Al4V under ultra-high power additive manufacturing

• A novel strategy utilizing near-spherical powder with 7500 W enables fabrication of high-performance HM Ti components. • The optimized process promotes diverse α variant nucleation at prior-β/β interfaces, suppressing large Widmanstätten α. • Incomplete recrystallization creates more high-angle grain boundaries, aiding lattice distortion absorption and dislocation proliferation. • Gradient interfaces and hardening endow HM Ti6Al4V with superior mechanical properties over cast-forged standards. Achieving satisfactory mechanical properties in high-power laser deposition (≥3000 W) for hybrid manufacturing titanium (Ti) alloy is still a great challenge. Herein, we proposed a novel strategy that utilizes near-spherical powder combined with ultra-high power (7500 W) to fabricate high-performance hybrid manufacturing (HM) Ti components. The near-spherical powder possesses complex subgrain structures during deposition. It tends to form β/β interface with a higher misorientation angle, facilitating diverse α variant nucleation sites at the boundaries. A more gradual gradient interface is formed under 7500 W ultra-high power, allowing for better strain coordination during deformation. Combined with the suppression of extensive Widmanstätten α and the formation of a well-interwoven α colony, the HM Ti6Al4V components exhibit excellent ultimate tensile strength (948 MPa), yield strength (850 MPa) and elongation (14.1 %), far exceeding the ASTM B381 forged standard. These insights offer a cost-effective strategy for producing high-performance Ti alloys through ultra-high power laser deposition, advancing the field of additive manufacturing by addressing key challenges in material design and mechanical properties optimization.