Functional properties of NiTi / Kapton nanocomposites deposited by electronic beam evaporation

Abstract

Shape memory effects were studied in a NiTi / Kapton composite produced by deposition of a thin layer of NiTi on a Kapton substrate by electronic beam evaporation. It was shown that after preliminary deformation by bending at room temperature, the composite demonstrated strain recovery on heating. An increase in preliminary strain increased the recoverable strain the maximum value of which was 2.1 %. The two-way shape memory effect was not observed due to a small thickness of the NiTi layer that did not exceed 300 nm. It was shown that the recoverable strain variation on cooling and heating under a stress was not observed due to the polymer creep on heating. The functional properties of the NiTi / Kapton composite produced by e-beam evaporation were compared to the behaviour of the NiTi / Kapton composite produced by the flash evaporation technique. It was shown that the value of the shape memory effect was comparable for both composites, whereas the irreversible strain was smaller in the samples produced by e-beam evaporation.