Influence of annealing on martensitic transformation and magnetic entropy change in Ni37.7Co12.7Mn40.8Sn8.8 magnetic shape memory alloy ribbon

doi:10.1016/j.jmmm.2014.10.077

Journal of Magnetism and Magnetic Materials

Volume 377, 1 March 2015, Pages 137-141

https://doi.org/10.1016/j.jmmm.2014.10.077 Get rights and content

Highlights

•
Annealing below or above 1173 K had different effects on transformation temperatures of Ni_37.7Co_12.7Mn_40.8Sn_8.8 ribbon, which was due to the formation of second phases.
•
A large magnetic entropy change of 15 J/kg K was obtained above 400 K in both the as-spun ribbon and that annealed at 973 K.
•
To achieve a giant high-temperature MCE in Ni_37.7Co_12.7Mn_40.8Sn_8.8 ribbon, the annealing temperature should not exceed 973 K.

Abstract

The microstructure, martensitic transformation and magnetic properties of Ni_37.7Co_12.7Mn_40.8Sn_8.8 high temperature magnetic shape memory ribbon subjected to different annealing temperature were investigated. Annealing up to 1073 K slightly raised the transformation temperatures and the transformation interval, while annealing at 1173 K considerably decreased the transformation temperature and strongly widened the transformation interval due to the formation of a second phase. The as-spun and annealed ribbon at 973 K exhibited giant magnetic entropy changes of around 15 J/kg K under 15 kOe magnetic field above 400 K. Further increasing annealing temperature caused a decrease of the magnetic entropy change. To achieve a large magnetocaloric effect while keeping an elevated transformation temperature, an appropriate annealing parameter should be carefully considered.

Introduction

Ni–Mn–Sn, including Ni–Co–Mn–Sn, magnetic shape memory alloys (MSMAs) have attracted much attention [1], [2], [3], [4]. Ni–Mn–Sn alloys undergo a first order magneto-structural transition between the paramagnetic/antiferromagnetic martensite phase and the ferromagnetic austenite phase upon heating and cooling [1], [5]. Due to a large magnetization change (ΔM) between the martensite and austenite, the phase transition can be driven by a moderate magnetic field resulting in a large magnetic-field-induced strain (MFIS), giant magnetocaloric effect (MCE) and magneroresistance (MR) [1], [2], [3], [6], [7], [8]. Compared with other Ni–Mn–X (X=In, Ga, Sb) MSMAs, Ni–Mn–Sn has relatively low cost, which makes it more competitive for practical applications. Recently, a giant MCE with an effective magnetic refrigeration capacity of 251 J/kg for 5 T near room temperature was reported in Ni₄₀Co₁₀Mn₄₀Sn₁₀ polycrystalline sample, revealing the promising prospect of Ni–Co–Mn–Sn as a room-temperature magnetic cooling material [9].

The melt spinning technique is an effective method to fabricate homogeneous MSMAs ribbons with a refined and highly textured polycrystalline microstructure [6], [10], [11], [12]. Due to the rapid solidification during processing, some lattice defects and internal stress may be introduced into the ribbons [13]. Thus, an appropriate post-annealing for a short time is of necessity. In addition, the ordering degree and the phase constitution would be changed by the post-annealing [14], which subsequently should have a remarkable effect on the martensitic transformation and magnetic properties. Up to now, some groups had reported the effect of annealing on the transformation temperatures, Curie temperature (T_c) and the MCE in MSMAs ribbons [5], [14], [15], [16], [17]. Whereas, it was evident that such a influence was very complex. For example, the peak magnetic entropy change (ΔS_m) of an as-spun Ni_44.1Mn_44.2Sn_11.7 ribbon increased from about 8–32.1 J/kg K by annealing at 1123 K and reduced to 20.1 J/kg K with additional annealing at 1173 K [5]. Liu et al. [14] also reported effects of annealing on Ni₄₅Mn₃₇In₁₃Co₅ and Ni₄₆Mn₃₅In₁₄Co₅ ribbons. For the former, annealing enhanced ΔM and promoted the magnetic-field-induced transformation (MFIT). In contrast, in the latter ribbon, with increasing the annealing time at 1173 K, the MFIT was smeared and the MCE was weakened due to the formation of second phase particles. Therefore, it is essential to carry out more investigations on the effect of annealing on various Ni–Mn–X ribbons, particularly those tending to precipitate the second phase in some cases.

In this paper, we prepared a Ni–Co–Mn–Sn ribbon with 12.7 at% Co undergoing a martensitic transformation above 373 K, which belonged to a high temperature MSMA. We found the presence of second phases after high temperature annealing, which was seldom reported in Ni–Co–Mn–Sn ribbon. We also discussed the effect of annealing on the microstructure, the martensitic transformation, and the MCE.

Section snippets

Experimental procedures

The as-cast Ni–Co–Mn–Sn alloy was inductively melted in a quartz tube and then ejected onto a rotating copper wheel to produce the ribbons. The surface velocity of the wheel was 10 m/s. Three ribbons were then sealed in vacuum quartz tubes and annealed for 30 min at 973, 1073 and 1173 K, followed by quenching in water. For simplicity, these three samples are denoted as A, B and C ribbons. The microstructure and atomic composition were examined by scanning electron microscopy (SEM) equipped with

Results and discussion

Fig. 1 shows the microstructures of the ribbons annealed at different temperatures. Martensite plates were present in the as-spun (Fig. 1a), A (Fig. 1b) and B (Fig. 1c) ribbons. For the C ribbon (Fig. 1d), a two-phase microstructure was found consisting of the martensite and the particulate-shaped second phase γ. EDS result showed that the detailed composition of γ phase was Ni_31.2Co_23.4Mn_43.7Sn_1.7 (at%). In comparison with the matrix (Ni_37.6Co_10.4Mn_40.3Sn_9.7), in the γ phase, the Co content

Conclusions

In summary, effects of the annealing temperature on the martensitic transformation and magnetic properties in Ni_37.7Co_12.7Mn_40.8Sn_8.8 ribbon were investigated. Annealing at 973 and 1073 K lead to a small rise in the transformation temperatures from 402 to 410 K for A_s and slightly widened the transformation interval. Annealing at 1173 K reduced the transformation temperatures (A_s≈317 K) and greatly increased the transformation interval, which could be ascribed to the formation of the Co-rich γ

Acknowledgment

We appreciate technical assistance of Nikole Kucza and Charles Patrick at the VSM, and Brittany Muntifering at the XRD. This work was supported by the National Natural Science Foundation of China (No. 51101040), Harbin Special Fund for Innovation Talents of Science and Technology (2013RFLXJ030), and the State Scholarship Fund of China. PM acknowledges financial support through the National Science Foundation through projects DMR-1207192 and CMMI-1068069, and NSF MRI award 0619795 (XRD).

References (26)

M. Khan et al.
J. Magn. Magn. Mater.
(2008)
K. Ito et al.
Scr. Mater.
(2009)
F. Chen et al.
Intermetallics
(2013)
F. Albertini et al.
J. Magn. Magn. Mater. 242–245 (
(2002)
J. Liu et al.
Acta Mater.
(2009)
W. Cai et al.
Scr. Mater.
(2008)
Y. Feng et al.
Mater. Lett.
(2009)
S.C. Ma et al.
J. Alloys Compd.
(2011)
F. Chen et al.
J. Magn. Magn. Mater.
(2013)
Y.Q. Ma et al.
Acta Mater.
(2009)

J. Liu et al.

Acta Mater.

(2008)

T. Krenke et al.

Nat. Mater

(2005)

R. Kainuma et al.

Appl. Phys. Lett.

(2006)

Cited by (18)

Influence of γ phase on the magnetostructural transition and magnetocaloric properties of Ni<inf>38</inf>Co<inf>12</inf>Mn<inf>41</inf>Sn<inf>9</inf> melt-spun ribbons
2023, Journal of Magnetism and Magnetic Materials
In the present work, Ni₃₈Co₁₂Mn₄₁Sn₉ melt-spun ribbons were annealed under different conditions to make samples free of secondary γ phase precipitates or get them with various average grain sizes. A comparative study was carried out to demonstrate how γ phase formation affects the martensitic transformation (MT) and the magnetocaloric properties linked to the first-order phase transition. The γ phase significantly reduces the structural transformation temperatures, while slightly increases the thermal hysteresis. The γ phase also decreases the maximum entropy change (|ΔS|^max) and the effect is more significant for smaller γ phase precipitates. As compared with those with coarse γ phase grains, the ribbons containing smaller ones possess a lower |ΔS|^max but a smaller maximum magnetic hysteresis loss.
Effect of carbide formation on phase equilibria and compositional modulation of transformation properties in (Mn,Fe)<inf>2</inf>(P,Si) alloys
2020, Journal of Alloys and Compounds
Practical implementation of efficient magnetocaloric effect-based refrigeration and energy conversion applications requires the design of whole alloy families with narrow tolerances on the transformation properties, and therefore composition, of the component alloys. In the promising class of magnetocaloric (Mn,Fe)₂(P,Si) alloys, this task of compositional tuning is made especially difficult by the observed co-existence of several P-depleted impurity phases, which for example, increases both the P content and transformation hysteresis losses of the main quaternary phase. In this work, we study the mechanisms that induce impurity phase formation in the Mn–Fe–P–Si system, and investigate the impact of sequential carbide formation on observed phase microstructure along with its effect on the composition and transformation properties of the (Mn,Fe)₂(P,Si) phase. Using quantitative analyses to measure the composition within main and impurity phases in samples throughout the bulk alloy space, we establish that (1) repeated processing steps increase the content of a (Mn,Fe)₉Si₂ carbide phase, resulting in (2) deviations in the magnetocaloric (Mn,Fe)₂(P,Si) phase from bulk nominal composition of up to ∼4 at. %. Finally, we map out (3) the dependence of transformation critical temperature, hysteresis, and enthalpy on the composition of the (Mn,Fe)₂(P,Si) phase of interest. Together, these results suggest carbon impurities can have a critical impact on magnetocaloric transformation properties in (Mn,Fe)₂(P,Si) alloys, since 0.3 wt % carbon content can cause critical temperatures and hystereses to deviate by more than 95 K and 8 K from desired design values.
Large magnetic entropy change and refrigeration capacity around room temperature in quinary Ni<inf>41</inf>Co<inf>9-x</inf>Fe<inf>x</inf>Mn<inf>40</inf>Sn<inf>10</inf> alloys (x= 2.0 and 2.5)
2020, Journal of Alloys and Compounds
Citation Excerpt :
Their large, and in some cases giant, MCE comes from the magnetostructural coupling (i.e., the strong coupling between the structural and magnetic transitions [1–3]). Among Ni–Mn-Z (Z = In, Sn, Ga and Sb) Heusler alloys, the large maximum magnetic entropy change ΔSMpeak [37,38,49–55], easily adjustable working temperature [56], low cost [57] and non-toxicity of raw materials [57] make Ni–Mn–Sn alloys promising candidates for their utilization as working substances in commercial cooling devices. However, brittleness and considerable magnetic field-induced hysteresis loss HL, still hinder their practical applications.
We report the magnetocaloric properties of two Fe-containing quinary bulk polycrystalline alloys of nominal compositions Ni₄₁Co₇Fe₂Mn₄₀Sn₁₀ and Ni₄₁Co_6.5Fe_2.5Mn₄₀Sn₁₀ that were determined by indirect and direct methods. Both samples showed a large refrigeration capacity RC and maximum magnetic entropy change ΔS_M^peak around room temperature. For a magnetic field change of 2 T (5 T), a large magnetic entropy change of 18.9 (22.4) J kg⁻¹ K⁻¹ and 11.8 (16.8) J kg⁻¹ K⁻¹ and a refrigeration capacity of 128 (396) J kg⁻¹ and 99 (313) J kg⁻¹ were found in Ni₄₁Co₇Fe₂Mn₄₀Sn₁₀ and Ni₄₁Co_6.5Fe_2.5Mn₄₀Sn₁₀ alloys, respectively. RC for the alloy Ni₄₁Co₇Fe₂Mn₄₀Sn₁₀, is among the largest value reported so far for Ni–Mn based Heusler alloys. Under a 1.5 T field change, the direct measurements showed the maximum adiabatic temperature changes ΔT_ad^max of −0.8 K and −1.5 K for these two alloys, respectively. The present findings point out the potential of Fe-alloyed Ni₄₁Co₉Mn₄₀Sn₁₀ Heusler alloys as room-temperature magnetic refrigerants.
Ni-Co-Mn-Sn quaternary alloys: Magnetic hysteresis loss reduction and ductility enhancement by iron alloying
2019, Journal of Magnetism and Magnetic Materials
Citation Excerpt :
Further, the cost and toxicity of raw materials and mechanical properties are also of practical importance. Ni-Co-Mn-Sn quarternary magnetic shape memory alloys (SMAs) are competitive candidates as magnetic refrigerant materials, due to their large maximum entropy change ΔSMpeak [4–12], easily adjustable working temperature [13], low cost [14] and non-toxicity of raw materials. However, brittleness and considerable HL are factors that hinder their practical application.
The influence of Fe-alloying on the structural transition temperatures, microstructure, and mechanical and magnetocaloric properties of polycrystalline Ni₄₁Co_9−xFe_xMn₄₀Sn₁₀ (at. %) (x = 0–3) alloys has been studied. The substitution of Fe for Co introduced the so-called γ phase when the Fe content exceeds 1 at. %. The transformation temperatures decreased almost linearly with increasing Fe content without alteration of the transformation sequence. The compressive strength and maximum compressive strain increased to 1270 MPa and 21.3 % for Fe content of 3 at. %. In addition, the fracture type changed gradually from typical intergranular cracking to transgranular cracking with increasing Fe content. Magnetic field-induced reverse martensitic transformation was modified by increasing the Fe alloying, leading to the reduction of magnetic hysteresis loss (∼ 82.5 % drop after addition of 3 at. % Fe) but at the expense of a significant reduction in the maximum magnetic entropy change value.
Magnetic field induced martensitic transition in Fe doped Ni-Mn-Sn-B shape memory ribbons
2019, Intermetallics
Citation Excerpt :
Ni-Mn-X (X = In, Sn, Sb) Heusler alloys exhibit some characteristic properties such as magnetic shape memory effect, magneto-thermal conductivity, elasta-caloric effect [7–9]. The Ni-Mn-Sn alloy seems as one of the most suitable systems for practical applications when the cost-performance relation considers [10]. But despite its many advantages, the evaporation of Mn during the fabrication of the Ni-Mn-Sn alloy has a destructive effect on the shape memory effect [5].
In this study, effect of the Fe-doping on the microstructural evolution, phase transformation and magnetoresistance properties of the Ni-Mn-Sn-B magnetic shape memory ribbons fabricated by melt-spinning technique were investigated. While the phase transition temperatures from austenite to martensite in the undoped ribbon was very close to room temperature, it was found that they decreased by the Fe-doping, which was attributed to decrease in the e/a value with the Fe-content. A voltage change of 5 μV at a constant current of 1 mA and at 283 K and in the magnetic range of 0–10 kOe was obtained, which is good value obtained for the Heusler alloys. The resistivity data measured in the martensitic − austenite transition region was overlapped at ∼90 kOe, which is clear evidence for the magnetic field-induced one way martensitic transition. The ribbons showed an antiferromagnetic behavior at low magnetic field and a ferromagnetic behavior at high magnetic fields. The Fe-doping to the Ni-Mn-Sn system caused a significant increase in the magnitude of the magnetization. The results showed that the melt-spinning technique used in the production of magnetic shape memory strips is very promising for magnetic sensor applications.
Thermal hysteresis dependent magnetocaloric effect properties of Ni <inf>50-x</inf> Cu <inf>x</inf> Mn <inf>38</inf> Sn <inf>12</inf> B <inf>3</inf> shape memory ribbons
2019, Intermetallics
In this study, the magnetocaloric effect in Ni_50-xCu_xMn₃₈Sn₁₂B₃ ribbons depending on Cu substitution (x = 0, 1, 3) was investigated. The martensitic transition (MT) temperature of the ribbons shifted to lower temperatures with increasing Cu content. An inverse giant magnetocaloric effect (IMCE) was observed around the MT. Furthermore, the MT temperature of the x = 0 parent ribbon is around room temperature, which is important for technological applications. The Cu substitution helped to tune magnetization difference $Δ M$ and hence the IMCE. The highest inverse magnetic entropy change $Δ S_{M}^{m a x}$ and the refrigerant capacity $R C$ was obtained in the x = 1 Cu substituted ribbon. It is found that the inverse magnetic entropy changes $Δ S_{M}$ were dependent on the thermal hysteresis. The average hysteresis losses ( $A H L$ ) determined during cooling and heating processes were extremely different, indicating that the $A H L$ is also thermal hysteresis dependent.

View all citing articles on Scopus

View full text

Influence of annealing on martensitic transformation and magnetic entropy change in Ni37.7Co12.7Mn40.8Sn8.8 magnetic shape memory alloy ribbon

Highlights

Abstract

Introduction

Section snippets

Experimental procedures

Results and discussion

Conclusions

Acknowledgment

J. Magn. Magn. Mater.

Scr. Mater.

Intermetallics

J. Magn. Magn. Mater. 242–245 (

Acta Mater.

Scr. Mater.

Mater. Lett.

J. Alloys Compd.

J. Magn. Magn. Mater.

Acta Mater.

Acta Mater.

Nat. Mater

Appl. Phys. Lett.

Influence of annealing on martensitic transformation and magnetic entropy change in Ni_37.7Co_12.7Mn_40.8Sn_8.8 magnetic shape memory alloy ribbon