Superelastic Deformation In Polycrystalline Fe-Ni-Co-Ti Alloys

The paper discusses the causes contributing to behavior of reversible γ↔α martensite transformation in aged polycrystalline Fe-Ni-Co-Ti alloys. The effect of chemical composition (doping), heat treatment, magnetic ordering on the magnitude of elastic energy E_a of martensite crystals formation and martensite transformation hysteresis ΔT has been studied. The experimental results of the deformation behavior of investigated alloys at various temperatures of test under uniaxial tension show that the alloys of Fe-Ni-Co-Ti system demonstrate the high- and low-temperature superelasticity. The reasons leading to an increase of superelastic deformation in polycrystalline alloys based on Fe-Ni-Co-Ti are analysed.