• Ti45Al8Nb-0.6C alloy exhibits a creep life of 137 h at 800°C/200 MPa, with a ductile-brittle mixed fracture mode.
• Dynamic in-situ precipitation of Ti3AlC phase enhances creep resistance by impeding dislocation motion and inducing defect structures.
• Creep deformation triggers pronounced B2 phase formation, deformation twinning, lamellar coarsening, and stacking faults.
• Extensive dynamic recrystallization during creep leads to fine recrystallized grains, contributing to improved creep performance.