Interdiffusion in β Phase of the Ternary Ti-Al-V System

The interdiffusion in Ti-rich β Ti-Al-V alloys has been investigated in the temperature range from 1323 to 1473 K. The direct interdiffusion coefficients, \\ ildeDAlAlTi and \\ ildeDVVTi, and indirect interdiffusion coefficients, \\ ildeDAlVTi and \\ ildeDVAlTi, are positive in the ternary alloys, and these four interdiffusion coefficients have slight concentration dependence. The values of \\ ildeDAlAlTi are larger than those of \\ ildeDVVTi, and the values of \\ ildeDAlVTi are also larger than those of \\ ildeDVAlTi. The repulsive interactions exist between Al and V atoms in the Ti-Al-V alloys, because the ratio values of indirect coefficient to direct one are positive. On the other hand, the interactions between Ti (solvent) and Al (or V) atoms are attractive in the present alloy, since the ratio of converted interdiffusion coefficients in the ternary alloys shows negative values.