The mechanical properties of NiTi-based shape memory alloys

Melton, K.N.; Mercier, O.

doi:10.1016/0001-6160(81)90165-6

Cited by 172 publications

(86 citation statements)

References 29 publications

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“…The linear variation in the stress to induce martensite as a function of temperature above Ms satisfies the Clausius-Clapeyron equation. The d/dT of the present alloy is determined to be about 3MPa/K, which is approximately equal to that (about 2.5MPa/K) for Ti-Pd-Cr alloy [13], but smaller than that (5ϳ20MPa/K) for TiNi alloys [14]. Compared with other shape memory alloys, the present experimental alloy shows a relatively high critical slip stress during the martensite variant reorientation.…”

Section: Stress-strain Curvesmentioning

confidence: 51%

The tensile behavior of Ti36Ni49Hf15 high temperature shape memory alloy

Wang

1999

Scripta Materialia

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Section: Stress-strain Curvesmentioning

confidence: 51%

The tensile behavior of Ti36Ni49Hf15 high temperature shape memory alloy

Wang

1999

Scripta Materialia

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“…The change in slope (or stress plateau) in Stage II ( Figure 5) is due to localized Lu¨ders-like martensitic reorientation to accommodate variants in preferred directions, which is often in the direction of the applied stress. [56,57] During quasi-static compression, not all of the martensite variants reorient within Stage II, and so the slope in Stage III is less steep since martensite reorientation continues to occur along with elastic deformation of the reoriented martensite as the strain increases. In contrast, during dynamic compression, more of the martensite variants reorient within in Stage II extending this region by about 1.2 pct more strain before the slope in Stage III becomes much more abrupt and exhibits a steeper slope.…”

Section: Discussionmentioning

confidence: 99%

Influence of Dynamic Compression on Phase Transformation of Martensitic NiTi Shape Memory Alloys

Qiu

Young

Nie

2015

Metall Mater Trans A

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Shape memory alloys (SMAs) exhibit high damping capacity in both austenitic and martensitic phases, due to either a stress-induced martensite phase transformation or a stress-induced martensite variant reorientation, making them ideal candidates for vibration suppression devices to protect structural components from damage due to external forces. In this study, both quasi-static and dynamic compression was conducted on a martensitic NiTi SMA using a mechanical loading frame and on a Kolsky compression bar, respectively, to examine the relationship between microstructure and phase transformation characteristics of martensitic NiTi SMAs. Both endothermic and exothermic peaks disappear completely after experiencing deformation at a strain rate of 10 3 s À1 and to a strain of about 10 pct. The phase transformation peaks reappear after the deformed specimens were annealed at 873 K (600°C) for 30 minutes. As compared to samples from quasi-static loading, where a large amount of twinning is observed with a small amount of grain distortion and fracture, samples from dynamic loading show much less twinning with a larger amount of grain distortion and fracture.

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“…Conventionally, most mechanical testing of SMAs has been carried out in uniaxial tension using wires or straight specimens cut from sheets [1][2][3][4][5][6][7][8][9], shapes that are the most commonly accessible forms for SMAs. Figure 1 shows typical engineering tensile stress-strain curves [7, 10} for the ferroelastic behaviour (a) and superelastic behaviour (b) of polycrystalline NiTi alloys.…”

Section: Nominal Stress-nominal Strain Curvesmentioning

confidence: 99%

Stress state effect on mechanical behaviour of shape memory alloys : Experimental characterisation and modelling

Orgéas

Favier

2001

J. Phys. IV France

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Abstract. As engineering components utilising the beneficial properties of shape memory alloys (SMA) become geometrically complex and as applications involve combinations of loading states, a full evaluation of the effects of stress state on stress-strain response of these materials becomes critical for the success of these applications. Such evaluation is required to establish reliable constitutive relationship to model the complex thermomechanical behaviour of SMAs. This paper is intended to present a non-exhaustive overview on studies and results dealing with experimental characterisation and modelling of the effects of stress state on mechanical behaviour of shape memory alloys. In that respect, our presentation is mainly focused on one hand on experimental results on superelastic and ferroelastic deformation of polycrystalline alloys and on the other hand on the modelling at the macroscopic level, yielding critical reorientation or transformation constitutive equations. INTRODUCTIONShape memory alloys (SMAs) are known to exhibit a range of novel thermomechanical properties due to thermoelastic martensitic transformations. The superelasticity is a quasi-elastic deformation far beyond the conventional elastic limit of the material when deformed at certain temperature above A p the finishing temperature of the reverse martensite-to-austenite transformation. This phenomenon is associated with stress-induced martensitic (SIM) transformation. If the temperature is lowered to below M p the finishing temperature of the forward austenite-to-martensite transformation, the deformation proceeds by martensite reorientation. Martensite may deformed by reorientation forth and back with alternating stresses in opposite directions. This deformation mode is known as the ferroelasticity, in recognition of its phenomenological similarity to ferromagnetism. The one-way shape memory effect is observed when a specimen deformed by martensite reorientation reverts to its original shape upon heating to above A f Numerous experimental works have been performed in the past three decades aiming at characterising the thermo-mechanical behaviour in order to provide experimental evidences for the establishment of constitutive models. These experimental studies have been devoted to both single-crystal and polycrystal specimens, mainly using Cu-based and NiTi SMAs. Most mechanical testing has been carried out in tension using wire specimens. Less work has been done to characterise properties under other stress states. As engineering components become geometrically complex and as applications involve combinations of loading states, it becomes important to characterise material properties in different stress states. This will allow the establishment of reliable constitutive equations to model the complex thermomechanical behaviour of SMAs.The present paper is intended to give a non-exhaustive overview on the studies and results dealing with experimental characterisation and modelling of the influence of stress state on mechanical behaviour of...

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The mechanical properties of NiTi-based shape memory alloys

Cited by 172 publications

References 29 publications

The tensile behavior of Ti36Ni49Hf15 high temperature shape memory alloy

The tensile behavior of Ti36Ni49Hf15 high temperature shape memory alloy

Influence of Dynamic Compression on Phase Transformation of Martensitic NiTi Shape Memory Alloys

Stress state effect on mechanical behaviour of shape memory alloys : Experimental characterisation and modelling

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