Ni4Ti3-precipitation during aging of NiTi shape memory alloys and its influence on martensitic phase transformations

Khalil‐Allafi, Jafar; Dlouhý, A.; Eggeler, Gunther

doi:10.1016/s1359-6454(02)00257-4

Cited by 628 publications

(334 citation statements)

References 23 publications

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“…This is naturally reasonable as the grain boundaries may provide the nucleation sites during precipitation. The similar distribution of Ti 3 Ni 4 precipitate was also observed in Ni-rich TiNi alloys (Ref 7,8). Further increasing the aging temperature to 600°C leads to the growth of the Ti 3 Ni 4 precipitate to about 200-300 nm (Fig.…”

Section: Methodssupporting

confidence: 77%

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Effect of Aging Treatment on Superelasticity of a Ti48.8Ni50.8V0.4 Alloy

Zhao

Liang

Liu

et al. 2012

J. of Materi Eng and Perform

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In this study, effect of aging treatment on microstructure, deformation behavior, and superelasticity of Ti 48.8 Ni 50.8 V 0.4 alloy was investigated. After aging at 400°C for 30 min, Ti 3 Ni 4 precipitates formed. With increasing aging temperature from 300 to 450°C, the yield strength of reoriented martensite increased due to the strengthening effect of Ti 3 Ni 4 phase, thus improved the shape recovery ratio and reduced the stress hysteresis. Further increasing the aging temperature, the size of Ti 3 Ni 4 precipitates increased and the coherency between precipitate and matrix gradually lost, leading to the decreasing yield strength of reoriented martensite and shape recovery ratio. Simultaneously, the stress hysteresis increased resulting from the hinder of plastic deformation to the interfacial movement during phase transformation. The critical stress to induce martensitic transformation continuously decreased with increasing aging temperature.

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Section: Methodssupporting

confidence: 77%

“…8 Ni 50.8 V 0.4 (at.%) in rod form was used. The samples were sealed in vacuum quartz tubes and then solution-treated at 900°C for 2 h followed by quenching into water.…”

Section: Methodsmentioning

confidence: 99%

Effect of Aging Treatment on Superelasticity of a Ti48.8Ni50.8V0.4 Alloy

Zhao

Liang

Liu

et al. 2012

J. of Materi Eng and Perform

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“…Other compounds, namely precipitates Ti ?2 Ni, Ni ?3 Ti, Ni ?3 Ti ?2 and Ni ?4 Ti ?3 are also observed for this system. Extensive studies [2,[10][11][12][13] have been performed studying the precipitation phenomena for NiTi shape memory alloys. The precipitates Ni ?4 Ti ?3 , Ni ?3 Ti ?2 , Ni ?3 Ti can form when the NiTi alloy is slightly Ni-rich.…”

Section: Figmentioning

confidence: 99%

Welding and Joining of NiTi Shape Memory Alloys: A Review

Oliveira

Miranda

Fernandes

2017

Progress in Materials Science

272

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“…The (Ni,Cu) 4 Ti 3 phase corresponds to Ni 4 Ti 3 phase in binary NiTi SMAs and forms in the NiTi matrix during the heat treatment process (400°C, 8 h). The formation of Ti 2 (Ni,Cu) and (Ni,Cu) 4 Ti 3 phase affects the Ni content of the (Ni,Cu)Ti matrix, which in turn has an influence on the martensite transformation temperatures [33]. As shown in the SEM image in Fig.…”

Section: Resultsmentioning

confidence: 96%

Mechanical Properties of NiTi-Based Foam with High Porosity for Implant Applications

Qiu

Young

2015

Shap. Mem. Superelasticity

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In order to better understand NiTi-based shape memory alloy foams for implant applications, Ni 40 Ti 50 Cu 10 foams were heat treated and then deformed under incremental and cyclic compression loading. After heat treatment, the microstructure consists of a (Ni,Cu)Ti matrix with small (Ni,Cu) 4 Ti 3 precipitates and a large Ti 2 (Ni,Cu) secondary phase. The heat-treated Ni 40 Ti 50 Cu 10 foam exhibits a two-step transformation, involving B19 0 ? B19 and B19 ? B2 on heating and B2 ? B19 and B19 ? B19 0 on cooling, respectively. One Ni 40 Ti 50 Cu 10 foam was compression loaded for 10 cycles at each subsequent strain level, i.e., 1, 2, 3, 4, 5, and 6 % strain. In each set of compressive stress-strain loops, the maximum stress level decreases due to plastic damage accumulation and/or retention of transformed martensite. Cross-sectional images from micro-computed tomography were collected during compression loading, which shows very uniform deformation without severe structural damage even up to 5 % strain. Localized deformation is visible at 6 % strain.

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Ni4Ti3-precipitation during aging of NiTi shape memory alloys and its influence on martensitic phase transformations

Cited by 628 publications

References 23 publications

Effect of Aging Treatment on Superelasticity of a Ti48.8Ni50.8V0.4 Alloy

Effect of Aging Treatment on Superelasticity of a Ti48.8Ni50.8V0.4 Alloy

Welding and Joining of NiTi Shape Memory Alloys: A Review

Mechanical Properties of NiTi-Based Foam with High Porosity for Implant Applications

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