• Adding 0.4 at.% Ta to Ti46Al1.5Cr8Nb alloy yields optimal compressive properties: strength of 2,434 MPa and strain of 33.1%.
• Ta addition refines lamellar colony size from 160.65 μm to 94.44 μm and increases B2 phase content from 12.49% to 21.91%.
• Ta shifts solidification path to lower Al concentrations, enhancing supercooling and promoting phase refinement.
• Property improvement is attributed to lamellar colony refinement, solid solution strengthening, and reduced c/a ratio of γ phase.