Effect of carbon addition on the microstructure and mechanical behavior of near equiatomic NiTi alloy wire

•NiTiC alloy wires were prepared by accurately adjusting the C content.•NiTi alloy with 0.03 wt% C exhibits excellent tensile strength and tensile fatigue life.•Stacking faults in different directions in eutectic TiC form Lomer-Cottrell locks.•Stacking faults occur in grain boundaries of eutectic TiC in contact with matrix.•Eutectic TiC hinders the movement of adjacent grain boundaries and dislocations.