Metastable equilibrium in the high-coercivity YuNDK35T5 alloy

X-ray diffraction investigations have been carried out on plates of the YuNDK35T5 alloy single crystals for studying metastable equilibrium in its highly coercive state. Temperature limits have been established for the phase existence when heating this alloy from the highly coercive state to 1270 deg C: the (β2+β) phases exist in the range from 20 to 700 deg C, the (β2+β+βsub(o)) phases - in the range from 700 to 86a deg C, the βsub(o) phase - in the range from 860 to 900 deg C, the (βsub(o)+γ) phases - in the range from 900 to 1200 deg C and the βsub(o) phase - at temperatures over 1200 deg C. The three-phase equilibrium at 700 - 860 deg C single-phase state at 860 - 900 deg C are metastable, being obtained on heating the alloy with a high coercive force, i.e. in a state of an elevated free (elastic) energy. The metastable equilibrium thus found is reversible