Additive manufacturing of Y ₂ O ₃ ‐modified TA15 titanium alloy: enhanced mechanical properties at room and high temperatures

Abstract Ensuring structural integrity in critical applications necessitates performance optimization of selective laser melted (SLM) TA15 alloys across room to elevated temperature regimes, demanding coordinated enhancement of their thermomechanical stability and microstructural reliability. This article demonstrated an SLM strategy for fabricating Y 2 O 3 ‐modified TA15 alloys with thermally adaptive mechanical properties. Systematic investigations reveal that bimodal Y 2 O 3 nanoparticles formed in TA15‐ x Y 2 O 3 alloy (primary Y 2 O 3 : formed during the liquid phase cooling; secondary Y 2 O 3 : precipitated from the α′ and β phase, maintaining the orientation relationship of , with the matrix.), enabling α‐lath refinement from 1.183 to 0.487 μm through synergistic nucleation promotion and growth inhibition (Thermal cycling, annealing). At room temperature, 0.1 wt% Y 2 O 3 optimizes strength‐plasticity balance (increased 14.7% ultimate tensile strength (UTS) to 1097 MPa, increased 11.4% elongation (EL)) via grain refinement and dispersion strengthening. However, excessive Y 2 O 3 fragments β phase and induces α/β interfacial voids, yet paradoxically enhances high‐temperature tensile strength by 18.5% (749 MPa) through intensified dislocation‐Y 2 O 3 interactions. This composition‐dependent transition correlates with the improved by Y 2 O 3 ‐induced α, β‐phase stabilization, establishing a dual‐phase optimization paradigm for temperature‐specific titanium alloy design.