Molecular dynamics simulations of martensitic transformation in iron

The aim of this PhD. thesis is to use molecular dynamics (MD) simulations to comprehend the mechanisms governing nucleation and growth of martensite phase in austenitic phases in iron. In view of this objective, the thesis is divided into five parts: Chapter 2 reviews previous investigations of the fcc-to-bcc transformation in iron by MD simulations; Chapter 3 performs a preliminary study of the nucleation and growth of bcc phase into fcc bulk in iron at existing bcc/fcc interfaces in the Nishiyama-Wassermann orientation relationship; Chapter 4 studies the mechanisms governing the growth of bcc phase at bcc/fcc interfaces in iron; Chapter 5 and 6 study the thermodynamics of the homogeneous and heterogeneous nucleation of bcc phase inside the fcc crystals, respectively; Chapter 7 illustrates the effects of external strain on the nucleation and growth of bcc phase in fcc iron with (and without) fcc/fcc grain boundaries. A more detailed description of each chapter are included below.