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Low-fatigue magnetic memory alloy and preparation method thereof

A memory alloy and magnetic technology, applied in the field of shape memory alloy, can solve the problems of short functional life, low frequency of use of industrial drives, etc., and achieve the effects of enhanced fatigue life, long fatigue life, and large magnetically induced strain

Inactive Publication Date: 2020-02-21
NANJING INST OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, conventional magnetic shape memory alloys generally have a relatively short functional life, which can only reach a few thousand times, which is far lower than the number of times industrial drives are used. A new type of magnetically controlled shape memory alloy with longer fatigue life to achieve its industrial promotion

Method used

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  • Low-fatigue magnetic memory alloy and preparation method thereof
  • Low-fatigue magnetic memory alloy and preparation method thereof
  • Low-fatigue magnetic memory alloy and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Prepare 400g composition as Ni 36.2 al 32.1 co 31.2 Eu 0.5 The low fatigue magnetic memory alloy, its preparation method is as follows:

[0028] S1. Ingredients: Weigh Ni, Al, Co, Lu with a purity of 99.99% respectively;

[0029] S2. Melting: Put the prepared raw materials in a crucible for vacuum melting, the melting conditions are: a.1×10 -3 The low vacuum state of MPa; b. melting temperature is 1600 ℃; c. melting process adopts magnetic stirring; d. melting time is 180s (according to formula t=K×(M -1 / 2 ) to obtain, where the element coefficient K is 9s g -1 / 2 , M is 400g);

[0030] S3. Magnetic field heat treatment: The alloy ingot obtained by the above vacuum smelting is subjected to vacuum magnetic field heat treatment, the treatment conditions are: temperature 710°C; time: 12 hours; vacuum degree: 1×10 -3 MPa; Applied magnetic field strength: 5×10 6 A·m-1 ; Magnetic field rise rate: 1000A m -1 ·s -1 ;

[0031] S4. Cooling: followed by furnace cooling, ...

Embodiment 2

[0034] Prepare 500g composition as Ni 38.9 al 27.4 co 33.i Eu 0.6 The low fatigue magnetic memory alloy, its preparation method is as follows:

[0035] S1. Ingredients: Weigh Ni, Al, Co, Lu with a purity of 99.99% respectively;

[0036] S2. Melting: Put the prepared raw materials in a crucible for vacuum melting, the melting conditions are: a.2×10 -3 The low vacuum state of MPa; b. melting temperature is 1610 ℃; c. melting process adopts magnetic stirring; d. melting time is 190s (according to formula t=K×(M -1 / 2 ) to obtain, where the element coefficient K is 8.5s g -1 / 2 , M is 500g);

[0037] S3. Magnetic field heat treatment: The alloy ingot obtained by the above vacuum melting is subjected to vacuum magnetic field heat treatment, and the treatment conditions are: temperature 720°C; time: 11 hours; vacuum degree: 2×10 -3 MPa; Applied magnetic field strength: 8×10 6 A·m -1 ; Magnetic field rise rate: 1000A m -1 ·s -1 ;

[0038] S4. Cooling: followed by furnace co...

Embodiment 3

[0041] Prepare 600g composition as Ni 35.5 al 29.1 co 34.7 Eu 0.7 The low fatigue magnetic memory alloy, its preparation method is as follows:

[0042] S1. Ingredients: Weigh Ni, Al, Co, Lu with a purity of 99.99% respectively;

[0043] S2. Melting: Put the prepared raw materials in a crucible for vacuum melting, and the melting conditions are: a.3×10 -3 The low vacuum state of MPa; b. the smelting temperature is 1620 ℃; c. the smelting process adopts magnetic stirring; d. the smelting time is 195s (according to the formula t=K×(M -1 / 2 ) to obtain, where the element coefficient K is 8s·g -1 / 2 , M is 600g);

[0044] S3. Magnetic field heat treatment: The alloy ingot obtained by the above vacuum smelting is subjected to vacuum magnetic field heat treatment, the treatment conditions are: temperature 730°C; time: 10 hours; vacuum degree: 3×10 -3 MPa; Applied magnetic field strength: 1×10 7 A·m -1 ; Magnetic field rise rate: 1000A m -1 ·s -1 ;

[0045] S4. Cooling: foll...

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Abstract

The invention provides a low-fatigue magnetic memory alloy and a preparation method thereof, and belongs to the field of shape memory alloys. Compared with other magnetic shape memory alloys, the alloy has the advantages of large magnetic-field-induced strain and long fatigue life. The chemical formula of the alloy is: NixAlyCozEuj, wherein x is greater than or equal to 34.8 and is less than or equal to 38.9; y is greater than or equal to 27.4 and is less than or equal to 32.5; z is greater than or equal to 30.8 and is less than or equal 35.6; j is greater than or equal to 0.5 and less than orequal to 1.0; x+y+z+j=100; and x, y, z and j represent molar percentage content. Compared with the existing materials, the low-fatigue magnetic memory alloy has the advantages that coherent ultrafinedispersively distributed Ni17Eu2 intermetallic compounds are formed in a matrix phase of the memory alloy, the magnetic-field-induced strain ability of the alloy is strengthened, the fatigue life ofthe alloy is also prolonged, the alloy has large magnetic-field-induced strain and long fatigue life, and the industrial application range of the alloy is greatly expanded.

Description

technical field [0001] The invention belongs to the field of shape memory alloys, in particular to a low-fatigue magnetic memory alloy and a preparation method thereof. Background technique [0002] Magnetic shape memory alloys have become one of the hotspots in the field of smart materials research due to their large reversible strain and high response frequency. Ferromagnetic shape memory alloys can undergo thermally induced martensitic transformation by cooling down to generate a twinned martensite phase with a modulated layered structure, and have large magnetocrystalline anisotropy energy and low twin interface movement energy. Twins are an important feature of martensite in shape memory alloys. When ferromagnetic shape memory alloys are below the Curie point and the martensitic transformation initiation temperature, the twin martensites can move the inner twins under the action of a magnetic field. The reorientation of the surface or the martensite-parent phase interf...

Claims

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Application Information

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IPC IPC(8): C22C30/00C22C1/02C22F1/00C21D1/04C21D1/773
CPCC21D1/04C21D1/773C22C1/02C22C1/023C22C19/058C22C19/07C22C30/00C22C2202/02C22F1/00C22F1/10
Inventor 巨佳刘壮康彦张思斌许永祥张慧巴志新李旋李华冠
Owner NANJING INST OF TECH
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