Thermal- and stress-induced martensitic transformations in [001]-oriented Ni44Fe19Ga27Co10 single crystals

The microstructures and martensitic transformations upon cooling/heating, and under a compressive load have been studied for [001]-oriented Ni44Fe19Ga27Co10 (at.%) single crystals after growth and following annealing at 1448 K for 1 h, followed by quenching. Heat treatment determined the microstructure of the high-temperature phase (crystal lattice, the presence of gamma-phase particles, and the formation of B2-phase nanodomains). A wide superelasticity temperature range of 277 K was found. Annealing led to an 80 K increase in the martensitic transformations temperatures, widening of transformations intervals, and an increase in the strength properties of the high-temperature phase by 100 MPa, which led to a shift of the superelasticity range towards high temperature.

Automated summary

The microstructures and martensitic transformations of [001]-oriented Ni44Fe19Ga27Co10 single crystals were studied after growth and annealing, showing an increase in strength properties and widening of superelasticity temperature range after annealing treatment.