Ternary diffusion and thermodynamic interaction in the β solid solutions of Ti-Al-Fe alloys at 1423 K

► The binary and ternary interdiffusion coefficients in Ti-rich β Ti-Al-Fe alloys have been determined at 1423 K using the extended Matano method. ► The main and cross interdiffusion coefficients are positive in the ternary alloys. ► The repulsive interactions exist between Al and Fe atoms in the ternary alloys. ► Al occur by vacancy diffusion mechanisms and Fe diffusion takes place by some kind of interstitial diffusion mechanism in β Ti-Al-Fe alloys.