Peculiarities of high-temperature superelasticity in Ni–Fe–Ga single crystals in compression

Resumo

The high-temperature superelasticity and temperature dependence of the yield stress of 14M and L1₀ martensite in [001]-oriented single crystals of Ni₅₄Fe₁₉Ga₂₇ (at %) in compression alloy have been studied. As the temperature increases, the sequence of stress-induced martensitic transformations (MTs) changes from L2₁–14M to L2₁–L1₀. The yield stress of L1₀ martensite weakly depends on the temperature and is 1.7 times lower than that of 14M martensite. The temperature interval of superelasticity in [001]-oriented single crystals of Ni₅₄Fe₁₉Ga₂₇ under compression is determined by the growth of critical stresses with increasing temperature, the coefficient of strain-hardening, and the yield stress of L1₀ martensite.