Diffusion processes inβ-Zr(Al) phase: a thermodynamic approach

The diffusion behaviour in the β-Zr(Al) solid solution phase was investigated in the te mperature range 1203-1323 K using a therm odynamic approach. The Boltzmann-Matano relation used for determining interdiffusion coefficients and the Darken's equations used for evaluating the intrinsic diffusion coeff icients from velocity of movement of markers in diffusion couples were modified suitably. The composition depen d- ent thermodynamic interdiffusion coefficients were evaluated using chemical potential gr adient. Composition and temperature dependence of the thermodynamic interdiffusion coefficients were also established. The thermodynamic intrinsic diffusion coefficients of Al and Zr and their temperature dependence were determined using the modified Darken's equations.