The formation of the two-way shape memory effect in rapidly quenched TiNiCu alloy under laser radiation

Abstract

The effect of pulsed laser radiation (λ = 248 nm, τ = 20 ns) on structural properties and shape memory behavior of the rapidly quenched Ti50Ni25Cu25 alloy ribbon was studied. The radiation energy density was varied from 2 to 20 mJ mm−2. The samples were characterized by means of scanning electron microscopy, x-ray diffraction, microhardness measurements and shape memory bending tests. It was ascertained that the action of the laser radiation leads to the formation of a structural composite material due to amorphization or martensite modification in the surface layer of the ribbon. Two methods are proposed which allow one to generate the pronounced two-way shape memory effect (TWSME) in a local area of the ribbon by using only a single pulse of the laser radiation. With increasing energy density of laser treatment, the magnitude of the reversible angular displacement with realization of the TWSME increases. The developed techniques can be used for the creation of various micromechanical devices.