Verformungsinduzierte Martensitbildung in einer Kupfer - Eisen-Legierung: Experimente und Modellierung

The influence of the mean size of austenitic Fe-precipitates in a copper matrix on their stability against a strain-induced martensitic transformation is studied. For this purpose rolling experiments are conducted using specimens containing differently sized particles. The progress of the transformation is monitored by measuring the magnetic susceptibility of the material as a function of the plastic strain. It follows an Avrami-type function. The stability of the precipitates increases with decreasing particle size. The predictions of a continuum mechanical model based on a thermodynamical concept agree with the experimental findings. The model makes possible the calculation of a size-dependent mechanical driving force and allows to study various transformation mechanisms.