In situ optical microscopy study of a phase transformation induced by the dezincification of beta Cu-Zn

The formation of the alpha fcc phase during the dezincification of beta Cu-Zn was in situ observed. The transformation temperature (470 °C) was close to the minimum temperature at which the transformation could be detected in previous works. The reason for choosing this temperature was that in this way the transformation proceeds sufficiently slowly, making it possible to observe clearly the nucleation stage and the growing process at the surface of the sample. The progress of the dezincification experiment was recorded as a function of time allowing to follow the growing process of fcc needles. The experiments indicated that the formation of the fcc precipitates takes place by a heterogeneous mechanism.