Influence of Sc addition on microstructure and transformation behaviour of Ni24.7Ti50.3Pd25.0 high temperature shape memory alloy

Ramaiah, K.V.; Saikrishna, C.N.; Bhagyaraj, J.; Gouthama,; Bhaumik, SK

doi:10.1016/j.intermet.2013.03.023

Cited by 16 publications

(9 citation statements)

References 26 publications

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“…Overall, these studies have indicated that the accumulation of residual strain is an issue during thermomechanical cycling of NiTiPd alloys. Consequently, precipitation strengthening [38][39][40], quaternary alloying [17,27,28,[41][42][43], and grain size refinements [31,44] have been investigated in order to improve the alloys' response. Modeling of NiTiPd has also been attempted to understand various fundamental properties using atomistic [45][46][47], semi-empirical [48] and constitutive [49] approaches.…”

Section: Introductionmentioning

confidence: 99%

Thermomechanical behavior and microstructural evolution of a Ni(Pd)-rich Ni24.3Ti49.7Pd26 high temperature shape memory alloy

Benafan

Garg

Noebe

et al. 2015

Journal of Alloys and Compounds

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The effect of thermomechanical cycling on a slightly Ni-rich Ni 24.3 Ti 49.7 Pd 26 (near stochiometric Ni-Ti basis with Pd replacing Ni) high temperature shape memory alloy was investigated. Aged tensile specimens (400 °C/24 hr/furnace cooled) were subjected to loadbiased thermal cycling in conjunction with microstructural assessment via in situ neutron diffraction and transmission electron microscopy (TEM), before and after testing. It was shown that in spite of the slightly Ni-rich composition and heat treatment used to precipitation harden the alloy, the material exhibited dimensional instabilities with residual strain accumulation reaching 1.5% over 10 thermomechanical cycles. This was attributed to insufficient strengthening of the material (insufficient volume fraction of precipitate phase) to prevent plasticity from occurring concomitant with the martensitic transformation. In situ neutron diffraction revealed the presence of retained martensite while cycling under 300 MPa stress, which was also confirmed by transmission electron microscopy of post-cycled samples. Neutron diffraction analysis of the post-thermally-cycled samples under no-load revealed residual lattice strains in the martensite and austenite phases, remnant texture in the martensite phase, and peak broadening of the austenite phase. Texture developed in the martensite phase was composed

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Section: Introductionmentioning

confidence: 99%

Thermomechanical behavior and microstructural evolution of a Ni(Pd)-rich Ni24.3Ti49.7Pd26 high temperature shape memory alloy

Benafan

Garg

Noebe

et al. 2015

Journal of Alloys and Compounds

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“…The microalloying enhanced the dimensional stability of the material during repeated thermomechanical cycling by increasing resistance against irreversible deformation processes, while only reducing the transformation temperatures by about 10 1C. A recent study by Ramaiah et al [15] supported this finding in a Ti 50.3 Ni 24.7 Pd 25 HTSMA alloyed with 1 at% Sc addition. The Sc-modified alloy exhibited a smaller thermal hysteresis compared to the ternary alloy, though transformation temperatures further decreased by 30 1C.…”

Section: Introductionmentioning

confidence: 84%

“…The problem is exacerbated for HTSMAs, since the materials, by definition, operate at elevated temperatures resulting in decreased strength levels and the possibility of thermally activated deformation processes [6,7,13]. Several solutions have been proposed to alleviate the dimensional instability problem in HTSMAs, all of which target improving the strength of the alloy through (a) solidsolution strengthening [8,14,15], (b) thermomechanical processing [9,16,17], and (c) precipitation hardening [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Influence of tantalum additions on the microstructure and shape memory response of Ti 50.5 Ni 24.5 Pd 25 high-temperature shape memory alloy

Atli

Караман

Noebe

2014

Materials Science and Engineering: A

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“…However, the phase stability of these precipitates limit the ability to achieve similar strengthening at higher transformation temperatures where precipitate coarsening begins to occur [19]. Because of this, there have been increased interest recently in microalloying to achieve solid-solution or interstitial strengthening [20,21]. Nevertheless, HTSMA systems designed to operate at temperatures above 400°C seldom show appreciable shape memory and superelastic behavior at the present time, and even in alloys that do, full recovery at any applied strain level is rarely observed.…”

Section: Unique Challenges Of High-temperature Shape Memory Alloysmentioning

confidence: 99%

Computational Thermodynamics and Kinetics-Based ICME Framework for High-Temperature Shape Memory Alloys

Arróyave

Talapatra

Johnson

et al. 2015

Shap. Mem. Superelasticity

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Over the last decade, considerable interest in the development of High-Temperature Shape Memory Alloys (HTSMAs) for solid-state actuation has increased dramatically as key applications in the aerospace and automotive industry demand actuation temperatures well above those of conventional SMAs. Most of the research to date has focused on establishing the (forward) connections between chemistry, processing, (micro)structure, properties, and performance. Much less work has been dedicated to the development of frameworks capable of addressing the inverse problem of establishing necessary chemistry and processing schedules to achieve specific performance goals. Integrated Computational Materials Engineering (ICME) has emerged as a powerful framework to address this problem, although it has yet to be applied to the development of HTSMAs. In this paper, the contributions of computational thermodynamics and kinetics to ICME of HTSMAs are described. Some representative examples of the use of computational thermodynamics and kinetics to understand the phase stability and microstructural evolution in HTSMAs are discussed. Some very recent efforts at combining both to assist in the design of HTSMAs and limitations to the full implementation of ICME frameworks for HTSMA development are presented.

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Influence of Sc addition on microstructure and transformation behaviour of Ni24.7Ti50.3Pd25.0 high temperature shape memory alloy

Cited by 16 publications

References 26 publications

Thermomechanical behavior and microstructural evolution of a Ni(Pd)-rich Ni24.3Ti49.7Pd26 high temperature shape memory alloy

Thermomechanical behavior and microstructural evolution of a Ni(Pd)-rich Ni24.3Ti49.7Pd26 high temperature shape memory alloy

Influence of tantalum additions on the microstructure and shape memory response of Ti 50.5 Ni 24.5 Pd 25 high-temperature shape memory alloy

Computational Thermodynamics and Kinetics-Based ICME Framework for High-Temperature Shape Memory Alloys

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