CN101148719A - Method for obtaining large magneto-strain NiMnGa mono-anamorphosis by strong magnetic field induction - Google Patents
Method for obtaining large magneto-strain NiMnGa mono-anamorphosis by strong magnetic field induction Download PDFInfo
- Publication number
- CN101148719A CN101148719A CNA2007101761476A CN200710176147A CN101148719A CN 101148719 A CN101148719 A CN 101148719A CN A2007101761476 A CNA2007101761476 A CN A2007101761476A CN 200710176147 A CN200710176147 A CN 200710176147A CN 101148719 A CN101148719 A CN 101148719A
- Authority
- CN
- China
- Prior art keywords
- nimnga
- magnetic field
- magnetization
- crystal
- variant
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Hard Magnetic Materials (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
The present invention discloses strong magnetic field inducing process to obtain NiMnGa single variant with great magnetic strain. Monocrystalline NiMnGa material is treated in strong magnetic field of 5-10 T at 25 deg.c and its martensite twin crystal is reorientated to induce single variant. The NiMnGa single variant may have magnetic strain as high as 50000 ppm, or 5 %.
Description
Technical Field
The invention relates to a NiMnGa functional material capable of generating a magnetic control shape memory effect, in particular to a processing method for obtaining a near single variant with large magnetic strain performance (more than 5 percent) by carrying out strong magnetic field (5-10T) processing on NiMnGa single crystal, and the international patent classification belongs to C22F3/00.
Background
As a novel functional material, shape Memory Alloy (SMA) can recover the shape under a certain condition to generate macroscopic strain and restoring force. The NiMnGa alloy integrates the advantages of large strain, high driving force, fast response speed and the like, so that the NiMnGa alloy is expected to become a novel driver material and is widely applied to the fields of national defense, aerospace and high technology.
An "method for improving magnetically-driven reversible strain amount of polycrystalline Ni2MnGa by magnetic field heat treatment" is disclosed in grant publication No. CN 1272464C. This patent document addresses Ni 2 The MnGa polycrystalline material is based on the principle that under the condition of a high-temperature (near Curie temperature) magnetic field (0.7T), the electron cloud arrangement of austenite is controlled through heat treatment, so that the easy magnetization direction is preferentially oriented along the direction of an external magnetic field, and 210ppm of magnetic strain is obtained.
Research shows that the large magnetic strain performance can be obtained only in the NiMnGa single variant, while the single crystal prepared by the crystal growth method is composed of self-coordinated martensite multi-variants, and the preferred arrangement of the variants needs to be realized by a certain process to obtain the similar single variant. The process currently used internationally is a unidirectional compression treatment along the <100> crystal orientation of the NiMnGa single crystal, by which a large magnetic strain of 6.0% has been obtained in the alloy 5M martensite. However, this process often results in cracking of the single crystal sample and is very prone to introduce many non-removable defects, which reduces the efficiency of sample preparation, and for single crystal samples with large aspect ratios, the unidirectional compression process may cause the sample to bend and deform, making it impossible to obtain a single variant, especially for single crystal samples of some special shapes or sizes.
Disclosure of Invention
The invention aims to provide a method for obtaining a NiMnGa single variant with large magnetic strain induced by a strong magnetic field, which comprises the steps of smelting a NiMnGa raw material, casting a rod, growing a single crystal to form a NiMnGa single crystal, and then repeatedly magnetizing the NiMnGa single crystal at the temperature of 18-25 ℃ under the magnetic field of 5-10T to obtain the NiMnGa near single variant. The NiMnGa near single variant prepared by the method has the performance of large magnetic strain of more than 5 percent, and the critical magnetic field of the magnetic strain is below 350 mT.
The invention relates to a method for obtaining the performance of large magnetic strain in NiMnGa monocrystal through magnetic field treatment, which has the advantages that: (1) The method can perform single-variant treatment on NiMnGa single crystals with different shapes, sizes and specifications, and the single crystals cannot be subjected to single-variant treatment by using a one-way compression process; (2) The problems that a single crystal sample is possibly cracked and crushed and the defects in the crystal are excessive are avoided, which cannot be avoided in the process of obtaining the single variant by the unidirectional compression process, the high-quality large-strain NiMnGa near single variant can be prepared, the large magnetic strain performance of more than 5 percent can be stably obtained, and the maximum magnetic strain capacity of the single variant is close to the theoretical maximum magnetic strain capacity.
Drawings
FIG. 1 shows Ni of the present invention 50 Mn 28.5 Ga 21.5 X-ray diffraction profile of the powder.
FIG. 2 shows Ni of the present invention 50 Mn 28.5 Ga 21.5 A plot of the magnetic strain of a near-singlet.
FIG. 3 is a schematic view of the orientation of a magnetized single crystal of a rod.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
The invention relates to a method for obtaining a near-single variant with large magnetic strain performance by processing NiMnGa monocrystal with a strong magnetic field, which comprises the following processing steps:
the first step is as follows: manufacturing NiMnGa bar
Preparing Ni, mn and Ga with the purity of 99.9 percent into a master alloy with target components; then the master alloy is put into a vacuum arc furnace, and the vacuum degree of the vacuum chamber is adjusted to 2-4 multiplied by 10 -3 Pa, filling argon to 0.3-0.7 multiplied by 10 5 Pa, repeatedly smelting for 3-5 times, and then casting into a NiMnGa bar;
the target component is Ni 48～53 Mn 25～30 Ga 16～26 ；
The NiMnGa bar having a length of 1.0mm prepared as described above was cut out as a sample for testing the room-temperature crystal structure. Grinding a sample into NiMnGa powder, performing X-ray diffraction analysis (XRD) on the NiMnGa powder on a Rigaku D/Max2200PC type X-ray diffractometer to obtain a 5-layer modulated body-centered tetragonal martensite structure at room temperature (25 ℃), and calculating the lattice constant of the NiMnGa powder to obtain the maximum magnetostriction of the NiMnGa single crystal of the component under the theoretical condition.
The lattice constant is calculated as follows:
from the XRD result, two peaks [ h ] of the NiMnGa powder at a diffraction wavelength lambda of 0.15405nm can be obtained 1 k 1 l 1 ]And [ h 2 k 2 l 2 ]And two diffraction angles theta corresponding to the two peaks 1 And theta 2 See fig. 1. The interplanar spacing of the NiMnGa tetragonal crystal can be obtained according to the Bragg equation, and the correlation formula of the interplanar spacing and the lattice constant is obtained
The NiMnGa powder is obtained by analysis in the range of [100]]Lattice constant a in crystal orientation, niMnGa powder in [001]]Lattice constant c in crystal orientation. The NiMnGa powder is 5 layers to modulate the body center squareMartensite structure, so NiMnGa powder is in [010]Lattice constants in crystal orientation b and [100]]The lattice constants a in the crystal orientation are the same.
The maximum value of the NiMnGa single crystal magnetic strain under the theoretical condition can be calculated according to the following formula:
δ max ＝(a/c-l)×100％，
the room-temperature structure of the obtained NiMnGa powder was determined by X-ray diffraction analysis to be a 5-layer modulation body-centered tetragonal system, the lattice constant a = b =0.55 to 0.62nm, the lattice constant c =0.52 to 0.60nm, and the theoretical maximum strain of the monotropic form was 4 to 7%.
The second step is that: production of NiMnGa single crystal
Cutting the NiMnGa bar obtained by the first step into a cylindrical material rod and a seed Crystal rod, placing the cylindrical material rod and the seed Crystal rod in an FZ-T-4000-H type photon heating suspension zone melting Crystal growth furnace produced by Crystal Systems company, and preparing the NiMnGa monocrystal by adopting a photon heating suspension zone melting method;
the technological parameters for preparing NiMnGa monocrystal are as follows:
regulating the vacuum degree of the vacuum chamber in the growth furnace to 2-4 x 10 -3 Pa；
Filling high-purity argon to 1.2-1.8 multiplied by 10 5 Pa, the flow speed of argon is 0.2-2.0L/min, and high-purity argon is used as flowing gas;
mounting a seed crystal rod on a lower shaft of a growth furnace, and suspending a cylindrical material rod on an upper shaft of the growth furnace; the rotation directions of the seed crystal bar and the cylindrical material bar are opposite, the rotation speed is 5-50 r/min, the length of a melting zone is 4-10 mm, and the gradient of the solidification temperature is 1-7 multiplied by 10 4 K/m, the growth speed of the crystal is 3-15 mm/h;
the crystal orientation of the NiMnGa single crystal is determined to be a [100] direction parallel to the central axis, a [010] direction and a [001] direction perpendicular to the central axis, respectively, which are perpendicular to each other, and direction lines of the [100] direction, the [010] direction and the [001] direction are perpendicular to each other, as shown in FIG. 3, by Laue analysis.
The third step: magnetization NiMnGa near single variant
Cutting the NiMnGa monocrystal obtained by the second step along the [100] direction, the [010] direction and the [001] direction respectively to obtain a cuboid monocrystal sample; then placing the cuboid single crystal sample in an EX-2530-30 type magnetizing apparatus produced by Shanghai Xianda electronic and magnetic gas company Limited for repeated magnetization treatment to prepare a NiMnGa near single variant;
magnetization conditions: (A) Applying a strong pulse magnetic field of 5-10T along the direction of the single crystal [100] at 18-25 ℃, magnetizing for 5-20 times to prepare a magnetizing part in the direction of [100], and measuring the change rate before and after magnetization by using a vernier caliper or a micrometer, wherein the change rate of the single crystal size is 0.1-3%;
(B) Applying 5-10T strong pulse magnetic field along the single crystal [001] direction at 18-25 deg.C, magnetizing for 5-20 times to obtain a magnetized piece in the [001] direction, and measuring the change rate before and after magnetization by using vernier caliper or micrometer, wherein the change rate of the single crystal size is 1-7%.
In order to better obtain the near-single variant, the magnetization processes (A) and (B) can be repeatedly carried out for a plurality of times until the magnetic strain amounts in the sufficient magnetization processes in any two different directions tend to be consistent and are close to the maximum magnetic strain amount of the NiMnGa single variant theory.
Near single transformation edge [100] of NiMnGa alloy]After being magnetized in a sufficient direction, along nearly monomorphic [001]]Gradually applying a magnetic field in the direction, measuring it [100]]The magnetic strain curve of the direction is obtained to obtain the saturation magnetic strain and the critical magnetic field intensity (mu) of the magnetic strain 0 H) c If this value is close to the theoretical value of the magnetic strain of the alloy single-variant, it is known that the magnetization treatment provides an approximately single-variant.
Example 1:
making Ni with length-diameter ratio less than 2 and magnetic strain of 6.2% 50 Mn 28.5 Ga 21.5 Near single variant
The first step is as follows: manufacturing NiMnGa bar
According to Ni 50 Mn 28.5 Ga 21.5 Preparing a master alloy by using target components; then the master alloy is put into a vacuum arc furnace, and the vacuum degree of the vacuum chamber is adjusted to 4 multiplied by 10 -3 Pa, filling argon to 0.7X 10 5 Pa, repeatedly smelting for 5 times, and casting into Ni 50 Mn 28.5 Ga 21.5 A bar material;
cutting the above-mentioned material to a length of 1.0mmObtained Ni 50 Mn 28.5 Ga 21.5 The bars were used as test specimens for testing the room temperature crystal structure. Firstly, grinding a sample into Ni 50 Mn 28.5 Ga 21.5 After powdering, the Ni was analyzed by X-ray diffraction (XRD) on a RigakuD/Max2200PC X-ray diffractometer 50 Mn 28.5 Ga 21.5 The powder had a 5-layer modulated body-centered tetragonal martensite structure at room temperature (25 deg.C), and Ni was calculated 50 Mn 28.5 Ga 21.5 Lattice constant of the powder, thereby obtaining Ni of the composition 50 Mn 28.5 Ga 21.5 Maximum amount of magnetic strain of a single crystal under theoretical conditions.
The lattice constant is calculated as follows:
from the XRD result, ni was found to be present at a diffraction wavelength of 0.15405nm 50 Mn 28.5 Ga 21.5 Two peaks [ h ] of the Bar powder 1 k 1 l 1 ]And [ h 2 k 2 l 2 ]And two diffraction angles theta corresponding to the two peaks 1 And theta 2 See fig. 1 for a description. Ni can be obtained from the Bragg equation 50 Mn 28.5 Ga 21.5 The interplanar spacing of the tetragonal crystal and the correlation of interplanar spacing with lattice constant
Resolved to obtain Ni 50 Mn 28.5 Ga 21.5 Powder is in [100]]Lattice constant in crystal direction a =0.595nm 50 Mn 28.5 Ga 21.5 Powder is in [001]]Lattice constant c =0.558nm in crystal direction. Due to Ni 50 Mn 28.5 Ga 21.5 The powder has a tetragonal martensite structure with 5 layers, so Ni 50 Mn 28.5 Ga 21.5 The powder is in [010]Lattice constants in crystal orientation b and [100]]The lattice constants a in the crystal directions are the same.
Ni under theoretical conditions 50 Mn 28.5 Ga 21.5 The maximum value of the amount of single crystal magnetic strain can be calculated according to the following formula:
δ max ＝(a/c-1)×100％，
Ni 50 Mn 28.5 Ga 21.5 the theoretical maximum strain of the single variant is 6.6%.
The second step: production of Ni 50 Mn 28.5 Ga 21.5 (Single Crystal)
Ni obtained by the first step 50 Mn 28.5 Ga 21.5 Cutting the bar into a cylindrical material rod and a seed rod, placing the cylindrical material rod and the seed rod in an FZ-T-4000-H type photon heating suspension zone melting crystal growth furnace produced by CrystalSystems, and preparing Ni by a photon heating suspension zone melting method 50 Mn 28.5 Ga 21.5 A single crystal;
production of Ni 50 Mn 28.5 Ga 21.5 The single crystal process parameters are as follows:
regulating vacuum degree of vacuum chamber in growth furnace to 4X 10 -3 Pa；
Filling high-purity argon to 1.8X 10 5 Pa, the flow speed of argon gas is 1.0L/min, and high-purity argon gas is used as flowing gas;
mounting a seed crystal rod on a lower shaft of a growth furnace, and hanging a cylindrical material rod on an upper shaft of the growth furnace; the rotation directions of the seed crystal rod and the cylindrical material rod are opposite, the rotation speed is 10r/min, the length of a melting zone is 10mm, and the solidification temperature gradient is 7 multiplied by 10 4 K/m, the crystal growth speed is 5mm/h;
the Ni is determined by analysis of the Laue method 50 Mn 28.5 Ga 21.5 The crystal orientation of the single crystal parallel to the central axis is [100]]In directions perpendicular to the central axis [010] respectively]Direction and [001]]Direction, and [100]Direction, [010]Direction and [001]]The directional lines of the directions are perpendicular to each other, as shown in fig. 3.
The third step: magnetic Ni production 50 Mn 28.5 Ga 21.5 Near single variant
Ni obtained by the second step 50 Mn 28.5 Ga 21.5 Single crystal edge [100]]Direction, [010]Direction and [001]]Directionally cutting to obtain a cuboid monocrystal sample; then testing the rectangular single crystalThe sample was repeatedly magnetized in an EX-2530-30 magnetizing apparatus manufactured by Shanghai Xianda Electron-magnetic gas Co., ltd to obtain Ni 50 Mn 28.5 Ga 21.5 A near single variant;
magnetization conditions: (A) Applying 5T strong pulse magnetic field along the direction of the single crystal [100] at 25 ℃, and magnetizing for 5 times to prepare a magnetizing piece in the direction of [100 ]; the rate of change of the sample before and after magnetization was measured by a vernier caliper or a micrometer, and the rate of change of the single crystal size was 1.4%.
(B) Applying 8T strong pulse magnetic field along the single crystal [001] direction at 25 ℃, and magnetizing for 5 times to obtain a magnetized piece in the [001] direction; the rate of change of the sample before and after magnetization was measured by a vernier caliper or a micrometer, and the rate of change of the single crystal size was 3%.
(C) Applying 10T strong pulse magnetic field along the direction of the single crystal [100] at 25 ℃, and magnetizing for 5 times to obtain a magnetizing piece in the direction of [100 ]; the rate of change of the sample before and after magnetization was measured with a vernier caliper or a micrometer, and the rate of change of the single crystal size was 4.8%.
(D) Applying 10T strong pulse magnetic field along the direction of the single crystal [001] at 25 ℃, and magnetizing for 5 times to obtain a magnetized piece in the direction of [001 ]; the rate of change of the sample before and after magnetization was measured with a vernier caliper or a micrometer, and the rate of change of the single crystal size was 6.2%.
Ni prepared by the above method 50 Mn 28.5 Ga 21.5 The near-single-variant was subjected to the measurement of the magnetostriction curve, as shown in FIG. 2, in which Ni was introduced 50 Mn 28.5 Ga 21.5 Near single variant edge [100]]After sufficient magnetization in a direction, along a nearly monomorphic [001]]Gradually applying a magnetic field in the direction, measuring it [100]]The directional magnetostriction curve, at a lower magnetic field of 400mT, obtains a large magnetostriction of 6.2%, the critical magnetic field strength (mu) of the magnetostriction 0 H) c Is 227mT.
Example 2:
making Ni with length-diameter ratio larger than 5 and magnetic strain of 5.7% 50 Mn 28.5 Ga 21.5 Near single variant
The first step is as follows: method for manufacturing NiMnGa bar
According to Ni 50 Mn 28.5 Ga 21.5 Preparing a master alloy by using target components; then the master alloy is put into a vacuum arc furnace, and the vacuum degree of the vacuum chamber is adjusted to 2 multiplied by 10 -3 Pa, filling argon to 0.3 × 10 5 Pa, repeatedly smelting for 5 times, and casting into Ni 50 Mn 28.5 Ga 21.5 A bar material;
analysis of Ni by X-ray diffraction (XRD) 50 Mn 28.5 Ga 21.5 The powder had a 5-layer modulated body-centered tetragonal martensite structure at room temperature (25 ℃). Ni 50 Mn 28.5 Ga 21.5 Powder is in [100]]Lattice constant in crystal direction a =0.595 in [ 001%]Lattice constant c =0.558nm in crystal direction at [ 010%]Lattice constant b =0.595nm in crystal orientation.
Ni 50 Mn 28.5 Ga 21.5 The theoretical maximum strain of the single variant is 6.6%.
The second step is that: production of Ni 50 Mn 28.5 Ga 21.5 (Single Crystal)
Ni obtained by the first step 50 Mn 28.5 Ga 21.5 Cutting the bar into a cylindrical material rod and a seed crystal rod, placing the cylindrical material rod and the seed crystal rod in an FZ-T-4000-H type photon heating suspension zone melt crystal growth furnace produced by CrystalSystems, and preparing Ni by adopting a photon heating suspension zone melting method 50 Mn 28.5 Ga 21.5 Single crystal;
production of Ni 50 Mn 28.5 Ga 21.5 The single crystal process parameters are as follows:
regulating vacuum degree of vacuum chamber in growth furnace to 2X 10 -3 Pa；
Filling high-purity argon to 1.2 multiplied by 10 5 Pa, the flow speed of argon gas is 2.0L/min, and high-purity argon gas is used as flowing gas;
mounting a seed crystal rod on a lower shaft of a growth furnace, and suspending a cylindrical material rod on an upper shaft of the growth furnace; the rotation directions of the seed crystal rod and the cylindrical material rod are opposite, the rotation speed is 20r/min,the length of the melting zone is 8mm, and the solidification temperature gradient is 5 multiplied by 10 4 K/m, the crystal growth speed is 10mm/h;
the third step: magnetic system of Ni 50 Mn 28.5 Ga 21.5 Near single variant
Ni obtained by the second step 50 Mn 28.5 Ga 21.5 Single crystal edge [100]]Direction, [010]]Direction and [001]]Directionally cutting to obtain a cuboid monocrystal sample; then placing the cuboid single crystal sample in EX-2530-30 type magnetizer produced by Shanghai Xianda electronic magnetic gas Co Ltd for repeated magnetization treatment to obtain Ni 50 Mn 28.5 Ga 21.5 A near single variant;
applying 10T strong pulse magnetic field along the direction of the single crystal [100] at 22 ℃, magnetizing for 10 times to test a group of deformation rates; A10T strong pulse magnetic field is applied along the single crystal [001] direction at 22 ℃, and the magnetization is carried out for 10 times to form a group of deformation rate tests. After repeated magnetization, the amount of the magnetic strain in each direction of the single crystal is shown in the following table:
for Ni with aspect ratio greater than 5 50 Mn 28.5 Ga 21.5 Near single modification, at a lower magnetic field of 410mT, a large magnetic strain of 5.7% is obtained, the critical magnetic field strength (mu) of which 0 H) c Is 308mT.
Example 3:
making Ni with length-diameter ratio less than 2 and magnetic strain of 6.2% 48 Mn 30 Ga 22 Near single variant
Ni production by the same production method as in example 1 48 Mn 30 Ga 22 Near single variant.
Ni 48 Mn 30 Ga 22 Powder is in [100]]Lattice constant in crystal direction a =0.594nm at [001]]Lattice constant in crystal direction c =0.559nm is at [010]Lattice constant b =0.594nm in the crystal direction.
Ni 48 Mn 30 Ga 22 The theoretical maximum strain of the single variant is 6.3%.
Rate of change after magnetization:
(A) Applying 5T strong pulse magnetic field along the direction of the single crystal [100] at 18 ℃, and magnetizing for 5 times to obtain a magnetized piece in the direction of [100 ]; the rate of change of the sample before and after magnetization was measured with a vernier caliper, and the rate of change of the single crystal size was 1.0%.
(B) Applying 8T strong pulse magnetic field along the single crystal [001] direction at 18 ℃, and magnetizing for 5 times to obtain a magnetized piece in the [001] direction; the rate of change of the single crystal size of the sample before and after magnetization was measured by a vernier caliper and found to be 2.3%.
(C) Applying 10T strong pulse magnetic field along the direction of the single crystal [100] at 18 ℃, and magnetizing for 5 times to obtain a magnetized piece in the direction of [100 ]; the rate of change of the single crystal size of the sample before and after magnetization was measured by a vernier caliper and was 4.3%.
(D) Applying 10T strong pulse magnetic field along the single crystal [001] direction at 18 ℃, and magnetizing for 5 times to obtain a magnetized piece in the [001] direction; the rate of change of the sample before and after magnetization was measured with a vernier caliper, and the rate of change of the single crystal size was 5.9%.
For Ni 48 Mn 30 Ga 23 Near single variant, at a lower magnetic field of 451mT, a large magnetostriction of 5.9% is obtained, the critical magnetic field strength (μ) of which 0 H) c Is 301mT.
The method is characterized in that a strong magnetic field is applied to the NiMnGa single crystal, so that under the action of the static magnetic energy generated by an external magnetic field, the NiMnGa single crystal generates shear stress which is larger than the twin crystal reorientation stress through the coupling effect between the NiMnGa single crystal and the magnetic crystal anisotropy, the martensite twin crystal reorientation in the single crystal is realized, and the martensite single crystal with large magnetic strain is induced, so that the large magnetic strain of more than 50000ppm (5%) is obtained.
The invention relates to a method for performing single-variant treatment by adopting a strong magnetic field, which is based on the strong magnetocrystalline anisotropy and the low twin crystal reorientation stress of NiMnGa alloy. In the ferromagnetic martensite state, the short axis of the tetragonal lattice of the alloy body core is strongly coupled with the easy magnetization axis of the magnetic domain, while the orientations of different variants of the self-coordinated state are different, and under the action of a magnetic field, the energy difference between the variants with different orientations acts on a variant interface to generate shear stress. Under the action of the shear stress, the volume fraction of a preferred variant in the martensite variant, wherein the magnetic moment direction is consistent with the external magnetic field direction, is increased, and the volume shrinkage even disappears of a non-preferred variant, wherein the magnetic moment direction is inconsistent with the external magnetic field direction. Thus, the NiMnGa single crystal gradually turns into a nearly single-variant during the magnetization process in which the easy magnetization axis of the NiMnGa single crystal gradually turns to the external magnetic field direction.
Claims (3)
1. A method for obtaining a NiMnGa single variant with large magnetic strain induced by strong magnetic field is characterized in that the magnetization treatment comprises the following treatment steps:
the first step is as follows: manufacturing NiMnGa bar
Preparing Ni, mn and Ga with the purity of 99.9 percent into a master alloy with target components; then the master alloy is put into a vacuum arc furnace, and the vacuum degree of the vacuum chamber is adjusted to 2-4 multiplied by 10 -3 Pa, filling argon to 0.3-0.7 multiplied by 10 5 Pa, repeatedly smelting for 3-5 times, and then casting into a NiMnGa bar;
the target component is Ni 48～53 Mn 25～30 Ga 16～26 ；
The second step: production of NiMnGa single crystal
Cutting the NiMnGa bar obtained in the first step into a cylindrical material rod and a seed crystal rod, placing the cylindrical material rod and the seed crystal rod in a photon heating suspension zone melting crystal growth furnace, and preparing the NiMnGa monocrystal by adopting a photon heating suspension zone melting method;
the technological parameters for preparing NiMnGa monocrystal are as follows:
regulating the vacuum degree of the vacuum chamber in the growth furnace to 2-4 multiplied by 10 -3 Pa；
Filling high-purity argon to 1.2-1.8 multiplied by 10 5 Pa, the flow speed of argon gas is 0.2-2.0L/min, and high-purity argon gas is used as flowing gas;
mounting a seed crystal rod on a lower shaft of a growth furnace, and suspending a cylindrical material rod on an upper shaft of the growth furnace; the rotation directions of the seed crystal bar and the cylindrical material bar are opposite, the rotation speed is 5-50 r/min, the length of a melting zone is 4-10 mm, and the gradient of the solidification temperature is 1-7 multiplied by 10 4 K/m, the growth speed of the crystal is 3-15 mm/h;
the third step: magnetization NiMnGa near single variant
Cutting the NiMnGa monocrystal obtained in the second step along the [100] direction, the [010] direction and the [001] direction respectively to obtain a cuboid monocrystal sample; then placing the cuboid monocrystal sample in a magnetizing machine for repeated magnetization treatment to prepare a NiMnGa near single variant;
magnetization conditions are as follows: (A) Applying 5-10T strong pulse magnetic field along the single crystal (100) direction at 18-25 ℃, magnetizing for 5-20 times to obtain a magnetizing piece in the (100) direction, and measuring the change rate before and after magnetization by using a vernier caliper or a micrometer, wherein the change rate of the single crystal size is 0.1-3%;
(B) Applying 5-10T strong pulse magnetic field along the single crystal [001] direction at 18-25 deg.C, magnetizing for 5-20 times to obtain a magnetized piece in the [001] direction, and measuring the change rate before and after magnetization by using vernier caliper or micrometer, wherein the change rate of the single crystal size is 1-7%.
2. The method for obtaining NiMnGa single variant with large magnetic strain induced by strong magnetic field according to claim 1, is characterized in that: in the magnetization condition of the third step, the magnetic strain quantities in the processes of repeating the steps (A) and (B) to two arbitrary times of sufficient magnetization in different directions tend to be consistent and are close to the maximum magnetic strain quantity of the NiMnGa single-variant theory.
3. The method for obtaining the NiMnGa single variant with large magnetic strain induced by the strong magnetic field according to claim 1, is characterized in that: the NiMnGa single variant has large magnetic strain performance of over 5 percent, and the critical magnetic field of the magnetic strain is below 350 mT.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2007101761476A CN100494438C (en) | 2007-10-22 | 2007-10-22 | Method for obtaining large magneto-strain NiMnGa mono-anamorphosis by strong magnetic field induction |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2007101761476A CN100494438C (en) | 2007-10-22 | 2007-10-22 | Method for obtaining large magneto-strain NiMnGa mono-anamorphosis by strong magnetic field induction |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101148719A true CN101148719A (en) | 2008-03-26 |
| CN100494438C CN100494438C (en) | 2009-06-03 |
Family
ID=39249415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2007101761476A Expired - Fee Related CN100494438C (en) | 2007-10-22 | 2007-10-22 | Method for obtaining large magneto-strain NiMnGa mono-anamorphosis by strong magnetic field induction |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100494438C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102228964A (en) * | 2011-06-21 | 2011-11-02 | 哈尔滨工业大学 | Method for preparing Ni-Mn-Ga ferromagnetic shape memory alloy continuous fibers by adopting spinning method |
| CN102719692A (en) * | 2012-07-13 | 2012-10-10 | 哈尔滨工业大学 | Preparation method of quasi-continuous pore nickel-manganese-gallium foam alloy |
| CN108251775A (en) * | 2018-01-26 | 2018-07-06 | 哈尔滨工业大学 | A kind of method for reducing the twin stress of polycrystalline nickel manganese gallium alloy |
-
2007
- 2007-10-22 CN CNB2007101761476A patent/CN100494438C/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102228964A (en) * | 2011-06-21 | 2011-11-02 | 哈尔滨工业大学 | Method for preparing Ni-Mn-Ga ferromagnetic shape memory alloy continuous fibers by adopting spinning method |
| CN102228964B (en) * | 2011-06-21 | 2012-09-26 | 哈尔滨工业大学 | Method for preparing Ni-Mn-Ga ferromagnetic shape memory alloy continuous fibers by adopting spinning method |
| CN102719692A (en) * | 2012-07-13 | 2012-10-10 | 哈尔滨工业大学 | Preparation method of quasi-continuous pore nickel-manganese-gallium foam alloy |
| CN102719692B (en) * | 2012-07-13 | 2013-11-06 | 哈尔滨工业大学 | Preparation method of quasi-continuous pore nickel-manganese-gallium foam alloy |
| CN108251775A (en) * | 2018-01-26 | 2018-07-06 | 哈尔滨工业大学 | A kind of method for reducing the twin stress of polycrystalline nickel manganese gallium alloy |
Also Published As
| Publication number | Publication date |
|---|---|
| CN100494438C (en) | 2009-06-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6293803B2 (en) | Magnetic phase transformation material, method for producing magnetic phase transformation material and use of magnetic phase transformation material | |
| CN101308718B (en) | Rare earth - iron super magnetostriction material | |
| Meng et al. | Magnetostriction of a Fe83Ga17 single crystal slightly doped with Tb | |
| WO2001055687A2 (en) | MAGNETOSTRICTIVE DEVICES AND METHODS USING HIGH MAGNETOSTRICTION, HIGH STRENGTH FeGa ALLOYS | |
| Dong et al. | Enhancement of mechanical properties of Tb0. 27Dy0. 73Fe1. 95 alloy by directional solidification in high magnetic field | |
| CN101148719A (en) | Method for obtaining large magneto-strain NiMnGa mono-anamorphosis by strong magnetic field induction | |
| Jia et al. | Influence of energy area densities on microstructure evolution and properties of laser direct energy deposited Ni-Co-Mn-Al-Y magnetic shape memory alloy | |
| Liu et al. | Effects of high magnetic fields on the crystal orientation and magnetostriction of a TbFe2 based alloy during treatment in the semi-solid state | |
| Zhao et al. | Stress dependence of magnetostrictions and strains in< 111>‐oriented single crystals of Terfenol‐D | |
| Chen et al. | Tailoring ferroic domains by introducing internal stress: Fe81Ga19 magnetostrictive alloy as an example | |
| Liu et al. | Magnetic-field-dependent microstructure evolution and magnetic properties of Tb0. 27Dy0. 73Fe1. 95 alloy during solidification | |
| Tu et al. | Enhancement of magnetostrictive performance of Tb0. 27Dy0. 73Fe1. 95 by solidification in high magnetic field gradient | |
| Wang et al. | Magnetostriction increase of Tb0. 3Dy0. 7Fe1. 95 alloy prepared by solidification in high magnetic fields | |
| CN113046619B (en) | Large-expansion-amount rare earth giant magnetostrictive material and preparation method thereof | |
| Mulyukov et al. | Properties of Fe-36% Ni Invar with nanocrystalline structure | |
| Mu et al. | Phase structures and magnetostriction of Fe 7 1. 3 Ga 2 8. 7 alloys prepared by different solidification rates | |
| Shi et al. | Structure, magnetic properties and magnetostriction in NdFe1. 9 bulk nanocrystalline alloys | |
| Ma et al. | Magnetostriction of< 1 1 0> oriented crystals in Tb0. 36Dy0. 64 (Fe1− xCox) 2 (x= 0–0.30) alloys | |
| Ma et al. | Magnetostriction of Tb0. 36Dy0. 64 (Fe1− xCox) 2 (x= 0–0.20)< 1 1 2>-oriented crystals | |
| Deng et al. | Study on the melt-textured technique in a magnetic field for giant magnetostrictive materials R–Fe alloy | |
| CN113073249B (en) | Preparation method of <111> + <110> preferred orientation giant magnetostrictive material TbxDy1-xFey | |
| CN116334472B (en) | Preparation method of <111> oriented rare earth-iron-based magnetostrictive material | |
| Yan et al. | Effect of Co on the martensitic transformation, crystal structure and magnetization of Ni 52.5 Mn 23.5 Ga 24 based ferromagnetic shape memory alloys | |
| CN114752837B (en) | Medium-entropy magnetostrictive alloy and preparation method and application thereof | |
| EP0140523B1 (en) | Directional solidification of bi/mnbi compositions |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090603 Termination date: 20091123 |