Effect of combined pulsed magnetic treatment and low-temperature annealing on the microstructure and mechanical properties of as-cast Ti-Al-X(Cr, V, Zr) alloy

γ-TiAl alloys are attractive for aerospace applications owing to their low density and excellent high-temperature properties. However, their widespread use in high-temperature components has been limited by a poor toughness and an unsatisfactory balance between strength and ductility. In this study, a hybrid approach combining pulsed magnetic field treatment with low-temperature annealing treatment (PMAT) is proposed to improve the mechanical performance of an as-cast Ti–Al–X(Cr, V, Zr) alloy. The treatment consists of pulsed magnetic processing at a magnetic induction of 3 T, followed by annealing at 600–700 ℃ for 1 h. Microstructural characterization revealed that the pulsed magnetic field induced a magneto-plasticity effect, which promoted dislocation rearrangement and phase transformation, leading to significant grain refinement from 620 μm to 125 μm and stimulating the precipitation of equiaxed γ grains. Subsequent annealing further optimized the defect structure by organizing dislocations into low-energy configurations such as dislocation walls and subgrain boundaries, thereby reducing lattice distortion and interplanar spacing. A refined basket-weave lamellar structure was obtained, accompanied by enhanced α₂/γ interfacial cohesion. As a result, the optimally processed sample achieved a tensile strength of 387.9 ± 2.52 MPa and an elongation of 4.2 ± 0.21 %, representing improvements of 26.0 % and 50.0 %, respectively, over the untreated alloy, along with a 67.3 % increase in fracture energy absorption. The lowered stacking fault energy and increased fault density restrict dislocation motion, enhancing both strength and ductility. This work demonstrates that PMAT provides an effective microstructural optimization route to overcome the strength–ductility trade-off in TiAl alloys.