Phase equilibria at 1073 K, 1173 K, and 1273 K in the Fe-Cu portion of the Fe-Cu-Al system were determined by a diffusion couple technique, metallography, and transmission electron microscopy (TEM). It is shown that there is a miscibility gap of the bcc phase which is divided into A2 + A2, A2 + B2 and B2 + B2 two-phase regions. Based on the experimental data of phase equilibria of the present as well as of previous studies, a thermodynamic assessment of phase equilibria was made, in which the order-disorder transition of the bcc phase is taken into account. The thermodynamic parameters of fcc, bcc, and liquid phases were evaluated to describe the Gibbs energy of each phase leading to a better fit between calculations and experimental findings above 1073 K.
|Number of pages
|International Journal of Materials Research
|Published - 1998 Dec