Energy consideration of the fcc(gamma)-> hcp(epsilon) martensitic transformation in Fe-Mn-Si based alloys

In order to understand the mechanism of the fcc(gamma)-->hcp(epsilon) marte nsitic transformation in Fe-Mn-Si based alloys, an energy analysis has been carried out. A general model considering the nucleation process was propos ed and the critical driving force was calculated. The discussion of the pos sible formation mechanism revealed that for spontaneous martensitic transfo rmation in Pe-Mn-Si based alloys with low stacking fault energy, the pole m echanism can not be supported. The fcc(gamma)-->hcp(epsilon) transformation is mainly dominated by the directly overlapping process of faults, startin g from an irregular manner and ending with a regular one, in the way of a s elf-accommodation mechanism.