Computer simulation of multiphase diffusion layers growth.

A mathematical model of processes taking place during a thermo-chemical heat treatment is presented. The paper focuses on the analysis of phenomena which occur when a diffusing element forms with an alloy a phase diagram containing three solid solutions. It was assumed that the concentration of elements on the phase boundaries in the diffusion layer are consistent with the phase diagram. The effect of the surface reactions and of the diffusion coefficient values on the kinetics of the growth of various phases is discussed in the light of solutions of Fick's second law. Using computer simulation a process of new phases formation on the surface is analysed.