AuCu-Sn pseudobinary phase diagram

A pseudobinary phase diagram was determined from powder X-ray diffraction (XRD) data derived from the addition of varying amounts of Sn to the AuCu alloy system. Prior to XRD studies, the alloy samples were initially solution-treated and quenched. They were then subjected to annealing at lower temperatures ranging from 200 to 450 °C for a duration of 20 000 min and then subsequently quenched in ice brine. The resulting phase diagram presented two significant results. First, it showed the existence of a AuCu III phase which was previously reported only in the Au-Cu-Ga ternary system. And second, it shows the existence of a AuCu III′ phase which Karlsen and co-workers designated as the 'B' phase in his early work concerning the Au-Cu-Sn alloy system.