The B19-phase transition and the related tensile properties of Ti50Ni30Cu20 shape memory alloys were investigated after hydrogen doping. The results revealed that the presence of hydrogen suppressed the B2–B19 transition by decreasing transformation enthalpies. Aging at room temperature lowered martensitic transformation temperature, which might have been associated with the variation of hydrogen contents and states. Ti50Ni30Cu20 shape memory alloys manifested high thermal cycling stability after the aging treatment. In addition, the increase in the hydrogen content was accompanied by an increment in detwinning stress of B19 phase, whereas the elongation of Ti50Ni30Cu20 alloys decreased. Based on our analysis, these effects were caused by the combined activities of different hydrogen states, including those of hydrides and solid-solution hydrogen.
AsaokaT (1995) Superelastic properties of Ti-Ni-Cu alloy under mild hydrogen absorbing condition. Journal de Physique IV5: C8-723–C8-728.
2.
BiscariniACampanellaRColuzziB. (1999) Martensitic transitions and mechanical spectroscopy of Ni50.8Ti49.2 alloy containing hydrogen. Acta Materialia47: 4525–4533.
3.
BiscariniAColuzziBMazzolaiG. (2003a) Extraordinary high damping of hydrogen-doped NiTi and NiTiCu shape memory alloys. Journal of Alloys and Compounds355: 52–57.
4.
BiscariniAColuzziBMazzolaiG. (2003b) Mechanical spectroscopy of the H-free and H-doped Ni30Ti50Cu20 shape memory alloy. Journal of Alloys and Compounds356–357: 669–672.
5.
FanGOtsukaKRenX. (2008) Twofold role of dislocations in the relaxation behavior of Ti–Ni martensite. Acta Materialia56: 632–641.
6.
FanGZhouYOtsukaK. (2006) Effects of frequency, composition, hydrogen and twin boundary density on the internal friction of Ti50Ni50−xCux shape memory alloys. Acta Materialia54: 5221–5229.
7.
GamaounFSkhiriIBouraouiT. (2013) Hydrogen effect on the austenite–martensite transformation of the cycled Ni-Ti alloy. Journal of Intelligent Material Systems and Structures25(8): 980–988.
8.
HeJGaoKSuY. (2004) The effect of hydride and martensite on the fracture toughness of TiNi shape memory alloy. Smart Materials and Structures13: N24.
9.
HirthJ (1980) Effects of hydrogen on the properties of iron and steel. Metallurgical Transactions A11: 861–890.
10.
HolecDFriákMDlouhýA. (2014) Ab initio study of point defects in NiTi-based alloys. Physical Review B89: 014110.
11.
KuběnováMZálešákJČermákJ. (2013) Impact of hydrogen-assisted heat treatments on microstructure and transformation path in a Ni-rich NiTi shape memory alloy. Journal of Alloys and Compounds577: S287–S290.
12.
MazzolaiGBiscariniAColuzziB. (2004) Ultrasonic investigation of the B2 ↔ B19 martensitic transition in a Ni40Ti50Cu10 alloy. Materials Science and Engineering: A370: 497–503.
13.
MazzolaiGBiscariniAColuzziB. (2006) Diffusion of hydrogen in the Ni30Ti50Cu20 shape memory alloy. Solid State Phenomena115: 51–56.
14.
MengXLLiHCaiW. (2015) Thermal cycling stability mechanism of Ti50.5Ni33.5Cu11.5Pd4.5 shape memory alloy with near-zero hysteresis. Scripta Materialia103: 30–33.
15.
Mohd JaniJLearyMSubicA. (2014) A review of shape memory alloy research, applications and opportunities. Materials & Design56: 1078–1113.
16.
NamTHSaburiTShimizuK (1990) Cu-content dependence of shape memory characteristics in Ti-Ni-Cu alloys. Materials Transactions JIM31: 959–967.
17.
OgawaTYokozawaEOdaT. (2015) Hydrogen embrittlement behavior of Ni-Ti shape memory alloy with different microstructures in acidic fluoride solution. International Journal of Mechanical and Materials Engineering10: 1–10.
18.
OtsukaKRenX (2005) Physical metallurgy of Ti–Ni-based shape memory alloys. Progress in Materials Science50: 511–678.
19.
RotiniABiscariniACampanellaR. (2001) Martensitic transition in a Ni40Ti50Cu10 alloy containing hydrogen: calorimetric (DSC) and mechanical spectroscopy experiments. Scripta Materialia44: 719–724.
20.
WuJXiaotaoZZhiguoW. (2005) Phase transformation behavior of a TiNiCu shape memory alloy electrolytically charged with hydrogen. Rare Metals24: 190–193.
YokoyamaKHamadaKMoriyamaK. (2001b) Degradation and fracture of Ni-Ti superelastic wire in an oral cavity. Biomaterials22: 2257–2262.
23.
YokoyamaKHirataYInabaT. (2015) Inhibition of localized corrosion of Ni–Ti superelastic alloy in NaCl solution by hydrogen charging. Journal of Alloys and Compounds639: 365–372.
24.
YokoyamaKKanekoKOgawaT. (2005) Hydrogen embrittlement of work-hardened Ni–Ti alloy in fluoride solutions. Biomaterials26: 101–108.
25.
YokoyamaKOgawaTTakashimaK. (2007a) Hydrogen embrittlement of Ni–Ti superelastic alloy aged at room temperature after hydrogen charging. Materials Science and Engineering: A466: 106–113.
26.
YokoyamaKTomitaMAsaokaK. (2007b) Hydrogen absorption and thermal desorption behaviors of Ni–Ti superelastic alloy subjected to sustained tensile-straining test with hydrogen charging. Scripta Materialia57: 393–396.
27.
YoshidaAYokoyamaKInabaT. (2012) Fracture and corrosion behaviors of Ni–Ti superelastic alloy under sustained tensile loading in neutral fluoride solution containing hydrogen peroxide. Journal of Alloys and Compounds544: 24–29.
28.
ZhangJSomsenCSimonT. (2012) Leaf-like dislocation substructures and the decrease of martensitic start temperatures: a new explanation for functional fatigue during thermally induced martensitic transformations in coarse-grained Ni-rich Ti–Ni shape memory alloys. Acta Materialia60: 1999–2006.
