Effect of Stress-Induced Martensite Aging on Martensite Variant Reorientation Strain in NiMnGa Single Crystals

Panchenko, E. Yu.; Timofeeva, Е. Е.; Pichkaleva, Maria; Tokhmetova, A. B.; Surikov, N. Yu.; Tagiltsev, A. I.; Chumlyakov, Y.I.

doi:10.1007/s40830-019-00242-5

Cited by 10 publications

(10 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At temperatures below A s , i.e., at 22 • C and 40 • C, the curves show a plateau corresponding to the irreversible twin variant reorientation process followed by the elastic deformation of the martensitic phase reaching maximum strain of 9% at 350 MPa at 22 • C. This induced strain is only partly recovered after the unloading resulting in a residual deformation of around 6% related to SIM stabilization. This strain value, resulting from the detwinning process in the martensitic microstructure, is in line with the obtained one in the <110> A compression tests of the martensitic phases in NiFeGaCo [19] and NiMnGa [36]. The curve at 60 • C, also obtained below A s , does not show the strain accumulation, only indicates the presence of the quasi-elastic σ-ε loop almost identical to the one for the oriented martensite obtained at 40 • C test.…”

Section: Resultssupporting

confidence: 88%

Temperature Dependent Stress–Strain Behavior and Martensite Stabilization in Magnetic Shape Memory Ni51.1Fe16.4Ga26.3Co6.2 Single Crystal

Lázpita,

Villa,

Villa

et al. 2021

Metals

View full text Add to dashboard Cite

The superelastic properties and stress-induced martensite (SIM) stabilization have been studied in a shape memory Ni51.1Fe16.4Ga26.3Co6.2 single crystal. The single crystal, characterized by a thermally induced forward martensitic transformation temperature around 56 °C in the initial state, has been submitted to compression mechanical testing at different temperatures well above, near and below the martensitic transformation (MT). After each mechanical test, the characteristic MT temperatures and the transformation enthalpy have been monitored by means of differential scanning calorimetry. At temperatures below MT, the stress–strain (σ–ε) curves show a large strain, around 6.0%, resulting from the detwinning process in the martensitic microstructure, which remains accumulated after unloading in the detwinned state of the sample as a typical behavior of the shape memory alloys (SMAs). After just two “σ–ε + heating” cycles the accumulation of strain was not observed any more indicating the formation of a two-way shape memory effect which consists in a spontaneous recovery of the aforementioned detwinned state of the sample during its cooling across the forward MT. Whereas the thermally induced shape recovery in conventional SMAs occurs at the fixed value of the reverse MT temperature, the heating DSC curves of the mechanically deformed martensite in the present work show a burst-like calorimetric peak at the reverse MT arising at temperatures essentially higher than the thermally activated one. This behavior is the result of the SIM stabilization effect. After a short thermal aging in the stress-free state, this effect almost disappears, showing a slight impact on the MT characteristic temperatures and the enthalpy. At temperatures higher than the transformation one, the SIM is not stabilized, as the mechanically induced martensite fully retransforms into austenite after the unloading. From the σ–ε curves, the critical stress, σc, as well as the values of Young’s moduli of martensite and austenite are determined showing linear dependences on the temperature with a slope of 3.6 MPa/°C.

show abstract

Section: Resultssupporting

confidence: 88%

Temperature Dependent Stress–Strain Behavior and Martensite Stabilization in Magnetic Shape Memory Ni51.1Fe16.4Ga26.3Co6.2 Single Crystal

Lázpita,

Villa,

Villa

et al. 2021

Metals

View full text Add to dashboard Cite

show abstract

“…These results, together with the results obtained in [15] will provide a good set of experimental data for better understanding of the effects of SIM-aging. This is the first time that after the recent first reports on the SIM-aging in this alloy [5,21,22] results of acoustic emission measurements have also been published.…”

Section: Introductionmentioning

confidence: 71%

“…Our results for the hysteresis loops can be compared with the results of [5] and [22], where the transformation strain versus temperature (ε∼T) after SIM-aging along [110] and [123] direction was carried out and the start and finish temperatures were determined from DSC runs in the as grown state of the same single crystal (Figure 5). Comparing Figures 3 and 5 we can conclude that the agreement is reasonable.…”

Section: Discussionmentioning

confidence: 99%

“…Comparing Figures 3 and 5 we can conclude that the agreement is reasonable. It is worth noting that according to [5] and [22] the shapes and the positions of the hysteresis loops after SIM-aging are very sensitive to the orientation of the uniaxial stress applied during SIM-aging and also to the twinning/detwinning of the martensite variant [5,6,22].…”

Section: Discussionmentioning

confidence: 99%

“…The sample underwent a compressive stress (along the [110] L21 direction) induced forward martensitic transformation at 423 K and it was followed by heat treatment at this temperature, under 175 MPa compressive stress, for 2 h along the [110] L21 ||[100] L10 direction (SIM-aged sample). These SIM-aged crystals undergo martensitic transformation to non-modulated tetragonal L1 0 martensite [5,22].…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Acoustic Emission Characteristics and Change the Transformation Entropy after Stress-Induced Martensite Stabilization in Shape Memory Ni53Mn25Ga22 Single Crystal

et al. 2020

Self Cite

View full text Add to dashboard Cite

Measurements have been carried out to compare stress-induced martensite stabilization aged (SIM-aged) and as grown shape memory Ni53Mn25Ga22 single crystals with the means of simultaneous differential scanning calorimetry (DSC) and acoustic emission (AE). Contrary to expectations, the position of the hysteresis practically did not change, whilst the width of the hysteresis increased, and the forward and reverse transitions became sharper in the SIM-aged sample. The energy distributions of acoustic hits showed regular power law behaviour and the energy exponents were slightly different for heating and cooling; this asymmetry had different signs for the SIM-aged and as grown samples. During heating, in accordance with the sharper transitions observed in the DSC runs, two well-marked jumps could be seen on the plot of cumulative number of the acoustic emission events. Therefore, these were attributed to high sudden jumps in the phase transition during heating observed in the DSC. The effect of the SIM-aging on the transformation entropy was also investigated and it was found that it was about 36% less in the case of the SIM-aged sample.

show abstract

Regularities of Functional Properties in Stress-Induced Aged Martensite Single Crystals of Ni51Fe18Ga27Co4 Ferromagnetic Alloy

et al. 2023

View full text Add to dashboard Cite

Effect of Stress-Induced Martensite Aging on Martensite Variant Reorientation Strain in NiMnGa Single Crystals

Cited by 10 publications

References 18 publications

Temperature Dependent Stress–Strain Behavior and Martensite Stabilization in Magnetic Shape Memory Ni51.1Fe16.4Ga26.3Co6.2 Single Crystal

Temperature Dependent Stress–Strain Behavior and Martensite Stabilization in Magnetic Shape Memory Ni51.1Fe16.4Ga26.3Co6.2 Single Crystal

Acoustic Emission Characteristics and Change the Transformation Entropy after Stress-Induced Martensite Stabilization in Shape Memory Ni53Mn25Ga22 Single Crystal

Regularities of Functional Properties in Stress-Induced Aged Martensite Single Crystals of Ni51Fe18Ga27Co4 Ferromagnetic Alloy

Contact Info

Product

Resources

About