The Cyclic Stability of the Superelasticity in Quenched and Aged Ni44Fe19Ga27Co10 Single Crystals

The effect of aging (at 773 K for 1 h) on the cyclic stability of superelasticity was studied in preliminarily quenched (after annealing at 1448 K for 1 h) Ni44Fe19Ga27Co10 [001]-oriented single crystals. It was shown that NiFeGaCo single crystals (both quenched and aged) exhibited highly stable superelasticity during more than 10(5) loading/unloading cycles in compression without destruction. The degradation of the superelasticity curves was divided into stages, and each stage of degradation was carefully considered. The precipitation of omega-phase particles led to a change in the degradation mechanism of superelasticity in the aged crystals. The main degradation mechanism for quenched crystals is a formation of uniform distribution of dislocations; for aged crystals, the microstructural degradation mechanisms consist of a non-uniform distribution of dislocations around the particles and the appearance of residual martensite.

Automated summary

The effect of aging on the cyclic stability of superelasticity in quenched and aged NiFeGaCo single crystals was studied. It was found that both quenched and aged crystals exhibited highly stable superelasticity during more than 10^5 loading/unloading cycles. The degradation of superelasticity was divided into stages, and the aging crystals showed different degradation mechanisms compared to the quenched crystals, including a non-uniform distribution of dislocations and the appearance of residual martensite.