Thermal stability of the unstable fcc-Fe50Cu50 phase prepared by mechanical alloying

Abstract

An unstable fcc-Fe50Cu50 alloy has been prepared by milling of elemental powder blends. The structure and the decomposition behavior of the alloy were studied by x-ray diffraction and Mössbauer spectroscopy. A broad distribution of different local environments of the iron atoms was observed in the fcc-FeCu phase. This indicates that Fe and Cu are mixed on an atomic level. In the initial state of decomposition, iron atoms precipitated coherently in the fcc-FeCu matrix as fcc-Fe particles. At higher annealing temperatures the particle size increased during the thermal treatment, and the fcc-Fe precipitates transformed into the bcc-Fe structure.