Beginning Time of Formation of New Phase in Fe-Zn Diffusion Couple during Non-isothermal Diffusion and Numerical Analysis for the Phase Growth Behavior.

Abstract

A numerical analysis for phase growth behavior in Fe-Zn multi-phase diffusion couple during non-isothermal diffusion has been proposed by taking formation process of a new phase into account. For the purpose, an equation which gives the beginning time of formation of new phase during the non-isothermal heating has been derived from an empirical equation which gives the beginning time during isothermal diffusion.By use of some special techniques so as to save an amount of computation time, concentration-distance curve in a binary alloy model have been calculated under the experimental condition that finite/semi-infinite diffusion couples are heated isochronally with different constant heating rates.