The cyclic stability of rubber-like behaviour in stress-induced martensite aged Ni49Fe18Ga27Co6 (at.%) single crystals

Timofeeva, E. E.; Panchenko, E. Yu.; Tokhmetova, A. B.; Eftifeeva, A. S.; Chumlyakov, Yu. I.; et al. Materials Letters.

In present work, the cyclic stability of the rubber-like behaviour (RLB) was investigated in Ni49Fe18Ga27Co6 (at.%) single crystals. Crystals were aged in the martensite phase at 423 K for 1 h under a compressive stress of 450 MPa, applied along the [1 1 0]B2||[1 0 0]L10-direction. The RLB was induced by a preliminary chemical stabilization of the oriented L10-martensite during stress-induced martensite aging (SIM-aging) and following the reversible reorientation of martensitic variants under a compressive stress applied along the [0 0 1]B2||[0 0 1]L10-direction. The high cyclic stability of the RLB was obtained in 200 loading/unloading cycles, due to the low reorientation stresses of the L10-martensite variants (no higher than 140 MPa) and the high strength properties of the L10-martensite (~1.6 GPa). The irreversible strain after 200 cycles did not exceed 0.6%. An increase in the number of cycles did not lead to the effect of destabilization of the L10-martensite.