High-temperature-stable La(Fe,Si)13-based multi-interstitial-atom hydride magnetic refrigeration material with large magnetic entropy change and preparation method thereof

A magnetic refrigeration material, high-temperature stable technology, applied in the direction of magnetic materials, metal hydrides, heat exchange materials, etc., can solve the problems of difficulty in ensuring the uniformity of interstitial hydrides, complex process flow, and reduced material performance. Rich, simple preparation process, low cost effect

Active Publication Date: 2011-06-15
INST OF PHYSICS - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] CN1450190A patent discloses a kind of NaZn 13 Type rare earth-iron-silicon (R-Fe-Si)-based intermetallic compound, and through direct smelting and annealing, the metal interstitial compound with low C content can be prepared. By changing the content of C atoms in the alloy, it can be adjusted within a certain range Curie temperature, but with the increase of interstitial C atoms, more and more α-Fe appears in the alloy, resulting in a decrease in magnetic entropy change and a decrease in refrigeration capacity; Interstitial compounds can adjust the Curie temperature in a wide range, and the magnetic entropy change is only slightly reduced. However, when the temperature exceeds 150 ° C, interstitial hydrogen atoms will be precipitated from the alloy, resulting in a decrease in material performance. The uniformity of the interstitial hydride prepared by the alloy is difficult to be guaranteed
In addition, according to the preparation method published in the patent, the suction temperature should be in the range of 0-800°C, the pressure should be in the range of 0.5-10 atmospheres, and the suction time should be in the range of 0-100 hours. Higher requirements are put forward; the method of absorbing hydrogen first and then dehydrogenating, on the one hand, makes the process more complicated, and on the other hand, it will also cause the appearance of impurity phase α-Fe
[0008] To sum up, it is difficult for existing materials to meet the requirements of practical magnetic refrigeration materials such as stable material performance, wide-range adjustable Curie point through composition changes near room temperature, large magnetic entropy change, and low hysteresis loss.

Method used

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  • High-temperature-stable La(Fe,Si)13-based multi-interstitial-atom hydride magnetic refrigeration material with large magnetic entropy change and preparation method thereof
  • High-temperature-stable La(Fe,Si)13-based multi-interstitial-atom hydride magnetic refrigeration material with large magnetic entropy change and preparation method thereof
  • High-temperature-stable La(Fe,Si)13-based multi-interstitial-atom hydride magnetic refrigeration material with large magnetic entropy change and preparation method thereof

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0084] Embodiment 1 prepares Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 Interstitial master alloy

[0085] The preparation formula is Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 The gap master alloy, the specific process is:

[0086] i) According to the chemical formula Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 Weighing materials, commercially available rare earth metal La, Pr (manufacturer name: Hunan Shenghua Rare Earth Metal Material Co., Ltd.) and Fe, Fe-C master alloy (carbon content is 4.03% by weight), and Si with purity higher than 99.9% by weight Raw materials are mixed; wherein, the rare earth metals La and R are excessively added by 5% (atomic percentage) to compensate for volatilization and burning loss during the smelting process;

[0087] ii) Put the raw materials prepared in step i) into the electric arc furnace, and evacuate to 2×10 -5 Above Pa, after cleaning 1 or 2 times with the usual high-purity argon gas cleaning method, use the usual method t...

Embodiment 2

[0101] Embodiment 2: prepare Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 H 0.6 and Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 H 1.2

[0102] interstitial master alloy Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 Introduce the interstitial H atoms again to prepare the chemical formula Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 h 1.2 and Pr 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 h 1.2 The compound, the specific process is:

[0103] The fresh Pr prepared by embodiment 1 0.3 La 0.7 Fe 11.5 Si 1.5 C 0.2 The interstitial master alloy is broken into particles, placed in a high-pressure container, and vacuumed to 2×10 -5 Above Pa, at 350°C, pass high-purity H into the high-pressure vessel 2 , the gas pressure is 1.0 and 1.5 atmospheres respectively, and the inhalation time is kept for 5 hours and 2 hours; then put the high-pressure container into water at room temperature (20°C), and at the same time, use a mechanical pump to remove the remaining hy...

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Abstract

The invention discloses a high-temperature-stable La(Fe,Si)13-based multi-interstitial-atom hydride magnetic refrigeration material with large magnetic entropy change and a preparation method thereof. By a method for introducing interstitial hydrogen atoms into an interstitial mother alloy which is La1-aRaFe13-bSibXc through hydrogen absorption treatment, a compound which is La1-aRaFe13-bSibXcHd shown as a chemical formula is prepared, wherein the compound has a cubic NaZn13 structure; R is one or more or the combination of rare earth elements; and X is one or more or the combination of C, B and the like. During the hydrogen absorption treatment, required hydrogen content can be achieved through primary hydrogen absorption by controlling hydrogen pressure, temperature and time. The compound can keep stable performance at the temperature of between room temperature and 350 DEG C and under the normal pressure, namely the hydrogen atoms can stably exist in gaps; moreover, the Curie point can be continuously and greatly adjusted in a range from180 K to 360 K through composition change, magnetic entropy change which is over two times higher than the magnetic entropy change of metal Gd can be achieved near room temperature, and loss caused by magnetic hysteresis is avoided. The refrigeration material is a very ideal room-temperature magnetic refrigeration material.

Description

technical field [0001] The present invention relates to a kind of magnetic material, particularly relate to a kind of high temperature stable La(Fe, Si) with large magnetic entropy change 13 Multi-interstitial hydride magnetic refrigeration materials. [0002] The present invention also relates to a preparation method of the above-mentioned magnetic refrigeration material. technical background [0003] Magnetic refrigeration is a green and environmentally friendly refrigeration technology. Compared with the traditional refrigeration technology that relies on gas compression and expansion, magnetic refrigeration uses magnetic substances as the refrigerant, which has no destructive effect on the atmospheric ozone layer and no greenhouse effect, and the magnetic entropy density of the magnetic refrigerant is larger than that of gas, so refrigeration The device can be made more compact. Magnetic refrigeration only needs to use electromagnets or superconductors and permanent m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K5/14H01F1/053
CPCH01F1/012C01B6/246
Inventor 赵金良沈保根胡凤霞沈俊李养贤孙继荣
Owner INST OF PHYSICS - CHINESE ACAD OF SCI
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