Nanocrystallization kinetics under instantaneous growth approximation: Experiments and cellular automata simulations

Nanocrystallization kinetics is analyzed in the frame of instantaneous growth approximation, which implies that the time required for a crystallite to reach its final size is negligible with respect to the time required for the nanocrystallization process. This approach strongly simplifies the kinetic analysis and allows us to obtain the nucleation rate from both isothermal and nonisothermal nanocrystallization processes. Moreover, as no constraining mechanism is considered but the absence of growth, the results could be discussed in the frame of Johnson–Mehl–Avrami–Kolmogorov theory with a growth index equal to zero. Cellular automata simulations are in agreement with the observed kinetics and microstructure.