Phase Equilibria in the Melting - Crystallization Region for Alloys in the Ti - TiNi - Sc0.53Ni0.47 - Sc Subsystem

Physicochemical analysis methods have been applied to the phase equilibria in the Ti - TiNi - Sc_0.53Ni_0.47 - Sc subsystem of the Ti - Ni - Sc ternary system. No ternary compounds are found in the subsystem. Isomorphous phases based on Ti₂Ni and Sc_0.72Ni_0.28 form continuous series of solid solutions (η) at subsolidus temperatures, as do the equiatomic compounds TiNi and Sc_0.53Ni_0.47. The crystallization of the η phase in the ternary system is incongruent, as in the binary systems Ti - Ni and Sc - Ni. The solidus surface for the Ti - TiNi - Sc_0.53Ni_0.47 - Sc subsystem has a nonvariant four-phase reaction of transition type at 830 °C. The compositions of the alloys that take part in it extend to the Sc - Ni side.