Nucleation at plane front in directionally solidified peritectic alloys

The directionally solidified microstructures of peritectic alloys are affected markedly by the nucleation and growth conditions. By using nucleation and constitutional supercooling criterion and assuming that the maximum interface growth temperature of phase growth is more stability in the directional solidification process, the composition range is theoretically developed for predicting the nucleation at the plane-front growth of properitectic and peritectic phases in an initial transient zone. The band-like microstructure occurs as a function of solidification distance and composition range is described on the basis of the purely diffusive model. The calculated results of Fe-Ni and Pb-Bi peritectic alloys are in agreement with their experimental data.