MARTENSITE AND EQUILIBRIUM PHASES IN HUME-ROTHERY NOBLE-METAL ALLOYS

On the basis of recently published data for the martensitic transforma tions in Cu-Zn-Al alloys, an evaluation of the phase stabilities of ma rtensitic and equilibrium phases in other noble-metal alloys has been made. The contributions which control the Gibbs energy of the differen t phases are discussed quantitatively. The most important of these are the stability of the disordered phases, the vibrational entropy, the influence of the long-range order characterized by pair interchange en ergies, the structure-dependent lattice distortions and the energies a ssociated with the stacking sequences in the different close-packed ph ases.