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 - Sc0.53Ni0.47 - Sc subsystem of the Ti - Ni - Sc ternary system. No ternary compounds are found in the subsystem. Isomorphous phases based on Ti2Ni and Sc0.72Ni0.28 form continuous series of solid solutions (η) at subsolidus temperatures, as do the equiatomic compounds TiNi and Sc0.53Ni0.47. 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 - Sc0.53Ni0.47 - 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.