Hou et al’s study of the interdiffusion behavior of the β-Ni(Al,Cr) phase at different temperature and composition configurations was considered. The two off-diagonal interdiffusion coefficients had been found to possess opposite signs. To explain this phenomenon, Hou et al. had utilized the diffusion potentials and mobilities described in the number-fixed frame of reference. They demonstrated that the thermodynamic factors were responsible for the opposite signs. However, it was pointed out here that the symmetric property of the thermodynamic matrix did not allow their explanation to be valid.

Comment on “Interdiffusion in the Β Phase Region of the Ni–Al–Cr System”. Y.Liu, D.Liang: Scripta Materialia, 2010, 62[8], 629-31