Crystallization of the amorphous phase and martensitic transformations in multicomponent (Ti,Hf,Zr)(Ni,Cu)-based alloys

Design and Development of Ti–Ni, Ni–Mn–Ga and Cu–Al–Ni-based Alloys with High and Low Temperature Shape Memory Effects

“…A complex of high mechanical properties of the rapidly quenched UFG alloy doped with copper (σ u , 850–1550 MPa; σ y , 620–1200 MPa; σ m , 100–50 MPa; δ, 9–12%; reactive stress σ r = σ y −σ m , 620–1110 MPa and a reversible deformation of the ε, 3–5%; Table 10) was received and a new method of obtaining high strength UFG SMEs alloys in the form of thin ribbons was proposed, based on the technology of spinning from the melt of the non-stoichiometric alloys Ti 50+x Ni 25−x Cu 25 (x ≤ ±1 at.%) and Ti 50+y Ni 25 Cu 25−y (y ≤ ±1 at.%) [44,45]. Similar structural changes needed for increasing strength and ductile properties were also found on Ni–Ti–Zr, Ni–Ti–Hf and (Ni, Cu) 50 (Ti, Hf) 50 alloys [56,57,58,59,60,61,62,63,64]. Thus, it was found that the creation of the FG and UFG structure could significantly improve or (in the case of strong strengthening due to extreme external influences) preserve the ductility of the alloys necessary for the implementation of SMEs.…”

“…An important feature of titanium nickelide doped by copper instead of nickel in concentrations exceeding 23–25 at.%, hafnium and zirconium instead of titanium exceeding 10–12 at.% is their ability to synthesize the alloys in the amorphous state by spinning from the melt [55,56,57,58,59,60,61,62,63,64,65,66,67,68,69]. As a result of the subsequent optimal heat treatment, it was possible to provide the formation of predominantly single-packet martensite with high-temperature SMEs, a high-strength and ductile UFG structure (Figure 13).…”

“…A noticeable improvement in the strength and ductile properties of titanium nickelide was achieved in the formation of the UFG structure that was formed via in advanced deformation thermal technologies using SPD (ECAP, HPT, multi-pass rolling and drawing into a strip, rod or wire) of initial large-size samples of Ti–Ni alloys (Table 9) [51,52,53,54,55,56,57,58,59,60,61,62].…”

Characterization of the Solidifying Microstructure in Ti₆₀(Ni_xCu_40-x)₄₀Alloys

“…Interest focuses on Ti-based amorphous alloys among others due to their unique properties such as high strength, elastic strain, low specific density, good wear and corrosion resistance. Most of the developed Ti-based BMGs such as Ti-Cu-Ni(-Sn), Ti-Zr-Cu-Ni-Sn, Ti-Cu-Ni-Si-B and Ti-Zr-Hf-Cu-Ni-Si-Sn [1][2][3][4], have small critical diameter not larger than 8 mm. Only a few of the Ti-based amorphous alloys possess even quite wide supercooled liquid region that shows good glass forming ability (GFA) and possibility of deformation into a bulk form [5].…”