HREM observations of continuously changing intermediate structures between f.c.c. and b.c.c. at the austenite-martensite interface

Abstract

Continuous lattice change from f.c.c. to b.c.c. as a function of subnanometric distance is observed near the austerite-marterisite interface in an Fe-Ni-Mn alloy transformed isothermally at low temperature. From detailed analysis of such lattice changes, it is concluded that the lattice deformation proposed by Kurdjumov and Sachs is the most appropriate one. The Bogers-Burgers mechanism on which the Olson-Cohen nucleation model is based is found to be inadequate to explain the present observations.