Phase transformations in Au–Fe melt spun alloys

Supersaturated Au80Fe20 and Au70Fe30 solid solutions have been obtained by melt spinning. Heat treatments of as-quenched ribbons in the temperature range between 320 and 550 °C induced the precipitation of a fcc Fe-rich phase. From structural and microstructural analysis of precipitates and residual matrix, a discontinuous (cellular) transformation mechanism has been observed. Calculated driving forces for nucleation of bcc and fcc phases suggest a critical role of defect concentration on observed phase transformations.