Influence of quenching on the martensitic transformation temperature in Au–47.5at.%Cd–Ag alloys

We determined bcc↔B2, B2↔L21 and martensitic transformation temperatures in Au–47.5at.%Cd–Ag alloys for a wide range of compositions, and examined changes in martensitic transformation temperatures by quenching from various temperatures for Au–47.5at.%Cd–15at.%Ag and Au–47.5at.%Cd–27at.%Ag alloys. It has been found that in spite of the differences in the long-range β-phase order of both alloys, the quenching behavior of the martensitic transformation temperatures is quite similar for each of them, i.e. the maximum depression of the transformation temperature due to quenching occurs when quenched from temperatures near 773 K corresponding well to the B2 order state. This result suggests that the short-range disorder in the B2 ordered phase causes the martensitic transformation temperature to decrease.