Multiphase field modeling of the eutectic growth at varying velocity

By multiphase field model, the stable and non-stable growths of eutectic CBr₄-C₂Cl₆ alloy are simulated. The simulated results of stable growth are accordant with Jackson-Hunt's eutectic theory, which proved that the model is reliable. For the non-stable growth under varying growth velocity, the results show that during step increase or step decrease in velocity, the mechanism of the lamellar spacing adjustment is through abrupt lamellar branching or progressive merging and annihilation accompanied the growing up by itself, respectively, moreover, there exists strong asymmetry between these two processes during lamellar adjustment. At the moment of step changing in velocity, the adjustment of lamellar spacing, the changes of average velocity and average interface undercooling have all the hysteresis effect.