The mechanisms of stress-induced transformation in ultimately fine-grained titanium nickelide, and critical grain size for this transformation

Dubinskiy, S.; Прокошкин, С. Д.; Sheremetyev, V.; Konopatsky, Anton S.; Korotitskiy, Andrey; Tabachkova, N. Yu.; Блинова, Е. Н.; Glezer, A. M.; Braïlovski, Vladimir

doi:10.1016/j.jallcom.2020.157733

Cited by 15 publications

(8 citation statements)

References 37 publications

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“…It was mentioned above that the grain boundaries can affect the nucleation and growth of martensite crystals, controlling the MT temperatures [ 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ]. A decrease in grain size, with a subsequent increase in the bulk density of the boundaries, is known to affect the nucleation of martensite crystals and the nature of MT propagation in a polycrystalline system [ 72 , 73 ].…”

Section: Resultsmentioning

confidence: 99%

TiNi-Based Material with Shape-Memory Effect for Surgical Treatment of Diseases of Small Intestine in Newborn and Young Children

Аникеев

Kaftaranova

Hodorenko

et al. 2023

JFB

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Alloys based on TiNi are widely used in various fields of technology and medicine. In the present work, we report on the preparation of TiNi-alloy-based wire with the shape-memory effect, which was used for compression clips for surgery. The composition and structure of the wire and its martensitic and physical–chemical properties were studied using SEM, TEM, optic microscopy, profilometry, mechanical tests, etc. The TiNi alloy was found to consist of B2 and B19’ and secondary-phase particles of Ti2Ni, TiNi3 and Ti3Ni4. Its matrix was slightly enriched in Ni (50.3 at.% of Ni). A homogeneous grain structure was revealed (an average grain size of 19 ± 0.3 μm) with equal quantities of grain boundaries of special and general types. The surface oxide layer provides improved biocompatibility and promotes the adhesion of protein molecules. Overall, the obtained TiNi wire was concluded to exhibit martensitic, physical and mechanical properties suitable for its use as an implant material. The wire was then used for manufacturing compression clips with the shape-memory effect and applied in surgery. The medical experiment that involved 46 children demonstrated that the use of such clips in children with double-barreled enterostomies permitted improvement in the results of surgical treatment.

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Section: Resultsmentioning

confidence: 99%

TiNi-Based Material with Shape-Memory Effect for Surgical Treatment of Diseases of Small Intestine in Newborn and Young Children

Аникеев

Kaftaranova

Hodorenko

et al. 2023

JFB

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“…The nanometre-sized martensite grains observed in the TEM image (Fig. 2 a) could have formed directly because of stress-induced martensitic transformation of nanometresized austenite grains that were formed as a result of EPR and some of them may have formed from the refinement of larger martensite grains formed during the initial stages of deformation [38,39]. Furthermore, the EPR process could have changed the transformation temperatures in such a way that the final material is martensitic at ambient temperature.…”

Section: Microstructure Of the Ns Nitimentioning

confidence: 99%

On the microstructure and tensile behaviour of nanostructured NiTi alloy produced by electroplastic rolling

et al. 2022

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Electroplastic rolling was employed to produce nanostructured (NS), near-equiatomic NiTi alloy from a coarse grained NiTi nugget (ingot), which was produced using vacuum induction melting, followed by quenching in water from a temperature of 800°C. The microstructure of NS NiTi was characterized using X-ray Diffraction (XRD) and transmission electron microscopy (TEM). XRD analysis revealed that the NS NiTi is predominantly martensitic at room temperature, with less than ≈10 % of the austenite phase. The NS NiTi alloy has an average grain size of ≈36 nm. TEM investigation confirmed the presence of grains that are less than 10 nm in size and no amorphous zones were detected. The NS martensitic NiTi alloy specimens were tested in tension at two different strain rates (10 −2 and 10 −1 s −1 ). In contrast to a stress-strain profile expected in a martensitic NiTi alloy, the stress-strain curves show conventional tensile behaviour. The observed UTS was high, around ≈1800 MPa, with a less than usual elongation to failure of ≈6 %. The presence of dimples on the fracture surfaces can be seen in scanning electron microscopy (SEM) images, which is indicative of ductile fracture. The role of grain size in the observed deformation and fracture features is also discussed.

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“…The trigger stress constantly decreases concerning the increase of grain size from hundreds of nanometres to about 400 µm [22]. Such descending tendency of trigger stress is more evident in Ti–50.61Ni alloy [23]. The trigger stress for stress-induced martensitic transformation substantially decreases from about 1000 to 200 MPa concerning the increase of grain size from 2.3 to 20 nm.…”

Section: Introductionmentioning

confidence: 99%

Grain size-dependent tensile behaviour in a metastable beta titanium alloy

Xiao

Shang

et al. 2022

Materials Science and Technology

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The present study investigates the effect of beta grain size on the stability of the beta phase in terms of trigger stress and the resultant mechanical properties of metastable beta titanium alloy. The trigger stress has a complex U-shaped relation concerning the beta grain size, which could be due to alternant mechanisms from interface friction and elastic energy. Nevertheless, the residual stress/strain could affect the trigger stress in the small grain size scale. More interestingly, dominant deformation modes are altered by a change of grain size with predominant stress-induced martensite (SIM) at small grain size and prime dislocation at large grain size, leading to grain size-dependent tensile behaviour of a metastable beta titanium alloy.

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The mechanisms of stress-induced transformation in ultimately fine-grained titanium nickelide, and critical grain size for this transformation

Cited by 15 publications

References 37 publications

TiNi-Based Material with Shape-Memory Effect for Surgical Treatment of Diseases of Small Intestine in Newborn and Young Children

TiNi-Based Material with Shape-Memory Effect for Surgical Treatment of Diseases of Small Intestine in Newborn and Young Children

On the microstructure and tensile behaviour of nanostructured NiTi alloy produced by electroplastic rolling

Grain size-dependent tensile behaviour in a metastable beta titanium alloy

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