Ternary interdiffusion coefficicents in α ₂ - phase Ti ₃Al/Nb system

The α ₂ single phase interdiffusion in Ti ₃Al-Nb ternary system was studied at temperatures of 1323, 1373 and 1423 K. The interdiffusion coefficients were calculated by the method of Dayananda. The average ternary interdiffusion coeffcients were determined in the mid of the diffusion zone, and the trace diffusion coefficients can be estimitaed in the limit c _X→0. The obtained main interdiffusion coeffcients is little smaller than privious reported and the diffusion activation energy of Nb calculated by the trace diffusion coefficients is 299.29 kJmol ^-1 accoding to the Arrhenius equation. These results can provide a theoretical basis for the mechanisms of Nb improving the oxidation resistance of Ti ₃Al.