Functional Fatigue of Ni–Mn–Ga and Ni–Ti Alloys with the Shape Memory Effect in Thermocycling Conditions under a Constant Stress

Abstract

We have performed comparative analysis of functional properties and functional fatigue of alloys of the Ni–Mn–Ga system in the initial molded state and the Ni–Ti system in the initial hot-forged state without thermal treatment. It is shown that the Ni2MnGa alloy in the molded state is preferable for low-loaded actuating elements (up to 100 MPa) and low recoverable strains (up to 1.5%) in the temperature range from –85 to –75°C; the Ni–Ti system alloy in the hot-forged state should be used for high-loaded actuating elements (up to 500 MPa) and high recoverable strains (up to 8.5%) in the temperature range from –40 to 40°C.