Interphase boundary diffusion of ~(44)Ti in two-phase TiAl with lamellar #alpha#_2/#gamma# structure

摘要

~(44)Ti self-diffusion in #alpha#_2/#gamma# interphase boundaries in two-phase PST-TiAl was measured for he first time. The diffusivity turns out to be in line with the GB self-diffusivity in Al-rich #alpha#_2-Ti_3Al. This phenomenon correlates with the specific atomistic structure of the #alpha#_2/#gamma# interfaces in two-phase PST-TiAl.The contribution of Ti GB diffusion along #gamma#/#gamma# twin interfaces was not possible to reliably detect on the present penetration profiles that means that this diffusion mode is much slower than Ti self-diffusion along the #alpha#_2/#gamma# interphase boundaries.