In the present study, the temperature dependence of martensite variant reorientation in stress-induced martensite aged at 423 K along the [110] B2 [100] L10 -direction Ni 49 Fe 18 Ga 27 Co 6 single crystals was inves- tigated in compression. This martensite aging induces a rubber-like behavior with a reversible strain of up to –16.0% along the [001] B2 -direction in the temperature range from 248 K to 344 K, which is caused by L 1 0 -martensite variant reorientation. At higher temperatures between the forward and reverse trans- formation from 344 K to 382 K, the stress-induced martensite aged crystals demonstrate a two-stage stress-strain response with a reversible strain of up to –13.5%. The first stage is characterized by low critical stresses of σcr1 ≈1 –15 MPa and an inverse elastocaloric effect (heat absorption) under load- ing. Superelasticity is observed in the second stage with σcr2 ≥100 MPa. In this temperature range, the martensite variant reorientation occurs through reverse and then forward martensitic transformation.
Scripta materialia. 2021. Vol. 194. P. 113618 (1-5)
Language
eng
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Сибирский физико-технический институт
Temperature dependence of martensite variant reorientation in stress-induced martensite aged Ni49Fe18Ga27Co6 single crystals