Functional properties of ‘Ti₅₀Ni₅₀–Ti_49.3Ni_50.7’ shape memory composite produced by explosion welding

Abstract

A bimetal composite, Ti50Ni50–Ti49.3Ni50.7, was produced by explosion welding, causing a Martensitic transformation. The functional properties of these objects were studied. It was found that explosion welding partially depressed the Martensitic transformation; however, a subsequent annealing resulted in the recovery of the kinetics of Martensitic transformations. Moreover, a variation in the annealing temperature allowed the control of a sequence of Martensitic transformations in the Ni-rich layer. The influence of the ratio of the equiatomic TiNi layer thickness to the total thickness of the bimetal composite on the recoverable strain was studied, and it was found that the maximum recoverable strain was observed when the thickness of the equiatomic TiNi layer was approximately equal to 55% of the total thickness of the sample. Functional properties were studied in the bimetal composite using the optimal ratio of the layer’s thickness. It was found that the value of the recoverable strain depended on the value of the residual strain as well as the sequence of the Martensitic transformations that occurred in the Ni-rich TiNi layer.

Influence of the initial structural-phase state on inelastic and plastic strains behavior in coarse-grained samples of the Ti49.3Ni50.7 (at.%) alloy

“…Titanium nickelide (TiNi) based alloys are applied in various technology and medicine fields as a functional material with superelasticity and shape memory effects (SME) [1][2][3]. These effects are due to thermoelastic martensitic transformations (MTs) from a high-temperature B2 phase to a monoclinic martensitic phase B19' [1,[4][5][6][7]. The manifestations of reversible inelastic deformation are determined by the position of the temperature of the isothermal loading-unloading cycles, T def , relative to the temperature ranges of the MT realization in the initial unloaded samples [5,[7][8][9].…”

On thermomechanical behaviors of the functional graded shape memory alloy composite for jet engine chevron

“…As for the researches on FG-SMA materials, the studies are mainly focused on the following situations: (1) graded SMA composites with different component fractions, such as gradient composites of NiTi alloy that with different fractions of NiTi and the other elastic material (Belyaev et al, 2010; Fu et al, 2003; Lester et al, 2011; Liu et al, 2013; Tian et al, 2009; Xue et al, 2013; Zheng et al, 2007a), two-phase materials with different gradient fractions of Ni and Ti (Belyaev et al, 2014; Lim et al, 2014; Martins et al, 2010; Yan et al, 2007), and the functionally graded porous SMA material with gradient variation porosity (Zhang et al, 2007). (2) FG-SMA material with the gradient transformation stress and the gradient transformation strain created through the different heat treatment processes or the adjustment of microstructure or geometric size of SMA material (Meng et al, 2012; Shariat et al, 2012, 2013a, 2013b).…”

“…The above reports on the FG-SMA materials are mainly focused on the material preparation, experimental testing, and experimental characterization (Belyaev et al, 2010(Belyaev et al, , 2014Lim et al, 2014;Martins et al, 2010;Meng et al, 2012;Razali and Mahmud, 2015;Tian et al, 2009;Yan et al, 2007;Zhang et al, 2007;Zheng et al, 2007a). However, the research on how to describe the mechanism of phase transformation and microstructure evolution is still in the initial exploring stage (Liu et al, 2013;Shariat et al, 2012Shariat et al, , 2013aShariat et al, , 2013b.…”