1. Martensitic transformations

1.1 General features

The term martensitic transformation was originally associated with the transformation that takes place during the quenching of steels: austenite formed at high temperature is transformed into martensite by rapid cooling to avoid diffusion. By extension, the term martensitic transformation designates transitions occurring in a number of alloys and presenting analogous characteristics described by the following definition.

The term first-order displacive means that the transformation involves small but finite...