CN112760535A - Magnetic refrigeration material and preparation method thereof - Google Patents
Magnetic refrigeration material and preparation method thereof Download PDFInfo
- Publication number
- CN112760535A CN112760535A CN202011530302.1A CN202011530302A CN112760535A CN 112760535 A CN112760535 A CN 112760535A CN 202011530302 A CN202011530302 A CN 202011530302A CN 112760535 A CN112760535 A CN 112760535A
- Authority
- CN
- China
- Prior art keywords
- magnetic
- magnetic refrigeration
- equal
- raw materials
- rare earth
- 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.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C22/00—Alloys based on manganese
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
- B22D11/0611—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by a single casting wheel, e.g. for casting amorphous metal strips or wires
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
- C09K5/02—Materials undergoing a change of physical state when used
- C09K5/06—Materials undergoing a change of physical state when used the change of state being from liquid to solid or vice versa
- C09K5/066—Cooling mixtures; De-icing compositions
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/02—Making non-ferrous alloys by melting
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/07—Alloys based on nickel or cobalt based on cobalt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C30/00—Alloys containing less than 50% by weight of each constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/02—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working in inert or controlled atmosphere or vacuum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/10—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of nickel or cobalt or alloys based thereon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/16—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/012—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials adapted for magnetic entropy change by magnetocaloric effect, e.g. used as magnetic refrigerating material
- H01F1/015—Metals or alloys
Abstract
The invention relates to a magnetic refrigeration material and a preparation method thereof, wherein a high-abundance rare earth element R is used for replacing Ni, Co, Mn and Ti, and the phase transition temperature can be effectively regulated and controlled. The preparation method of the material comprises the following steps: weighing high-purity raw materials according to the stoichiometric ratio of the chemical formula and uniformly mixing; then preparing the raw materials into a magnetic phase-change material by adopting an electric arc melting or pulling method or a directional solidification method; arc melting is carried out on the high-purity raw materials under the protection of argon to obtain a block sample; and finally, performing vacuum melt rapid quenching on part of the block sample obtained by arc melting to obtain a thin strip or performing vacuum annealing. The phase transition temperature is regulated and controlled within a wide temperature range of 100-350K along with the increase of the content of the high-abundance rare earth elements, and an enhanced magnetocaloric effect is obtained. The method has wide application prospect in production and life of room temperature magnetic refrigeration, high temperature heat pump and the like. The high-abundance rare earth is efficiently developed and utilized, and the balanced utilization of rare earth resources is facilitated.
Description
Technical Field
The invention relates to the field of magnetic materials, and relates to a magnetic refrigeration material and a preparation method thereof.
Background
With the increasing awareness of sustainable development along with economic development, the traditional gas compression technology is gradually eliminated. The magnetic refrigeration technology appearing in recent years receives wide attention due to the advantages of energy conservation, high efficiency, environmental protection, stability and reliability. Magnetic refrigeration is a type of refrigeration based on the Magnetocaloric Effect (Magnetocaloric Effect) of magnetic materials. The basic principle of magnetic refrigeration is to utilize the magnetocaloric effect of magnetic refrigeration material, i.e. the magnetic refrigeration material emits heat to the outside when magnetized and absorbs heat from the outside when demagnetized, so as to achieve the purpose of refrigeration. When the magnetic field is applied and demagnetized, the change of the entropy value is accompanied, so that the system has heat exchange with the surrounding environment.
Heusler alloy is one of the magnetic refrigeration materials. Such alloys have a ferromagnetic martensitic transformation behaviour. The ferromagnetic martensitic transformation in Heusler alloys is p2Found in MnGa. The method is characterized in that the first-order structure phase change is coupled with the second-order magnetic structure phase change. Since then, a ferromagnetic martensite phase change material system based on the Heusler alloy is continuously developed, and becomes a research hot tide. In the ferromagnetic martensite phase transformation process, the magnetism and the structure mutually influence to bring a plurality of physical effects, including the shape memory effect induced by a magnetic field, the strain output induced by the magnetic field, the magnetoresistance, the exchange bias, the magnetic entropy change and the like. In general, in the Heusler alloy, p-D hybridization of main group element atoms occupying D position, transition group element atoms occupying A/C position and D positioned at the most adjacent A/C position atom forms a covalent bondDetermines the structure and phase stability of the alloy. Wenchangyang et al propose an all-d-metal Heusler alloy consisting entirely of transition group metal elements based on the structural characteristics of Heusler alloys. And proposes a prediction: the transition group elements with multiple electrons and the transition group elements with few electrons can form d-d full shell hybridization to obtain the Ni-Mn-Ti all-d-metal Heusler alloy with atoms occupying high order and stable cubic structure, and the prediction is verified by experiments. Furthermore, the parent phase of the Ni-Mn-Ti all-d-metal Heusler alloy is antiferromagnetically coupled, and ferromagnetic coupling of the parent phase can be established by introducing magnetic elements such as Co (Fe) and the like into the Ni bit, and meanwhile, the low saturation magnetic moment of the martensite phase is kept, so that ferromagnetic martensite phase transformation is successfully realized, and the alloy becomes a new type of ferromagnetic shape memory alloy. In the alloy, the phase change behavior and the magnetocaloric effect of the alloy can be regulated and controlled through the substitution of elements with different atomic radii, so that the magnetic refrigeration can be realized in a wider temperature range. Rare earth elements are very good doping elements. Among rare earth elements, Pr, Nd, Dy, Tb and the like are consumed greatly as main required elements of rare earth permanent magnet materials, so that La, Ce and Y elements with high abundance and low price are accumulated in a large quantity, and the utilization of the rare earth elements is seriously unbalanced. The high-efficiency development and utilization of high-abundance rare earth or mixed rare earth become research hotspots, and have important significance for the balanced utilization of rare earth resources. The Ni-Co-Mn-Ti-based alloy is doped with abundant rare earth elements R (La, Ce and Y), so that the phase change and magnetocaloric effects can be regulated and controlled to adapt to different environments, and the current unbalanced situation of rare earth utilization can be relieved. The rare earth element is doped in the alloy, so that the valence electron concentration can be adjusted, the phase transition temperature can be regulated and controlled, and the magnetocaloric effect can be improved. At present, rare earth is expensive and the crust content is low, so that the rare earth is regulated and controlled by introducing abundant rare earth elements R (La, Ce and Y).
According to the invention, the Ni-Co-Mn-Ti-based material is doped with abundant rare earth elements R (La, Ce and Y) to regulate and control the phase change temperature, enhance the magnetocaloric effect of the material and simultaneously improve the utilization rate of the abundant rare earth elements.
Disclosure of Invention
In order to achieve the purpose, the invention provides a magnetic refrigeration material and a preparation method thereof.
The invention is realized by the following technical scheme:
a magnetic refrigerating material, an all-d-metal Heusler alloy with high-abundance rare earth elements R (La, Ce, Y) doped to improve Ni-Co-Mn-Ti-based magnetocaloric effect, has a chemical formula of Nix1-a1Cox2-a2Mnx3-a3Tix4-a4RaWherein x1 is more than or equal to 0 and less than or equal to 50, x2 is more than or equal to 0 and less than or equal to 50, x3 is more than or equal to 0 and less than or equal to 50, and x4 is more than or equal to 0 and less than or equal to 50; r is La, Ce, Y; a1+ a2+ a3+ a4 ═ a (0 < a ≦ 20).
In an all-d-metal alloy system of Ni-Co-Mn-Ti, the invention obtains a new alloy by replacing Ni, Co, Mn and Ti with high-abundance rare earth elements R (La, Ce and Y). The high-abundance rare earth elements R (La, Ce and Y) in the invention replace Ni, Co, Mn and Ti, and the phase transition temperature can be effectively regulated and controlled. The atom occupation condition and the magnetic atom spacing in the regulation and control process can be changed along with the introduction of the components, the exchange effect of the magnetic atoms is enhanced, the magnetization difference before and after the phase change is further increased, and the magnetic response effect is facilitated. The magnetic entropy change value accompanying the first-order magnetic phase change is increased, so that a large magnetocaloric effect is obtained.
Preferably, the phase transition temperature range of the material is 100-350K, and the Curie temperature range is 300-400K.
The invention can regulate and control the phase transition temperature in the range covering the room temperature, can obtain large magnetization intensity difference, further shows enhanced magnetocaloric effect, and is beneficial to the application of magnetic refrigeration in the large temperature range covering the room temperature. The invention has better application prospect in the response room temperature of devices and equipment.
According to the material disclosed by the invention, as the content of high-abundance rare earth elements R (La, Ce and Y) replacing Ni, Co, Mn and Ti is increased, the phase transition temperature of the structure is regulated within 100-350K, and the Curie temperature of the parent phase is regulated within 300-400K.
The maximum magnetic entropy change value of the material is 6.2Jkg under the change of a 0-20 kOe magnetic field-1K-1(ii) a Under the change of a 0-70 kOe magnetic field, the maximum magnetic entropy change value is 12.6Jkg-1K-1。
The invention covers large magnetic entropy variation value of room temperature range, and can be effectively applied to solid magnetic refrigeration technology in production and life under wide temperature range and low magnetic field covering room temperature.
The invention also relates to a method for preparing the magnetic refrigeration material, which comprises the following steps:
(1) weighing high-purity (more than or equal to 99.99 percent) raw materials according to the stoichiometric ratio of the chemical formula, uniformly mixing, wherein Mn is a volatile element, and adding 1 percent more to compensate loss in the smelting process;
(2) preparing the raw materials into a magnetic phase-change material by adopting an electric arc melting or pulling method or a directional solidification method; arc melting is carried out on the high-purity raw materials under the protection of argon to obtain a block sample;
(3) performing vacuum melt rapid quenching on part of the block sample obtained by arc melting in the step (2) to obtain a thin strip;
(4) carrying out vacuum annealing heat treatment on the sample in the step (2) or (3) at different temperatures;
preferably, the vacuum degree of arc melting is less than 4X 10-3Pa。
Preferably, when the single crystal is grown by the pulling method, the raw material in the magnetic suspension cold crucible is heated to 1200-1400 ℃ by adopting radio frequency of 245kHz, the heating power is 20kW, the seed crystal rod is lifted at a uniform speed of 3-80 mm/h by adopting a seed crystal rotation speed of 0-50 rpm, and a single crystal rod with the diameter of 10mm and the length of 100mm is obtained.
Preferably, when the polycrystal is prepared by the directional solidification method, the polycrystal is heated to 1350 ℃ by the radio frequency of 245kHz and the heating power is 25kW, and the polycrystal oriented material with the diameter of 25mm and the length of 150mm is obtained at the growth rate of 30 mm/h.
Preferably, the rotation speed of the copper wheel in the preparation process of the step (3) is 10-45m/s, the length of the thrown thin strip is about 1-20 cm, and the thickness of the thrown thin strip is about 10-35 mu m.
Preferably, the degree of vacuum in the vacuum annealing is less than 1X 10-3Pa, the annealing temperature is 500-1000 ℃, the annealing time is 0-5 days, and furnace cooling treatment or quenching treatment is carried out after the annealing is finished.
Through high-abundance rare earth elements R (La, Ce and Y), the phase change temperature can be randomly regulated and controlled within a range covering room temperature, the magnetocaloric effect is obviously enhanced, and the method has important application to the response of the solid magnetic refrigeration working medium to an external field in a room temperature environment.
Therefore, the invention has the following advantages:
the material of the invention can transform from a high-temperature ferromagnetic parent phase to low-temperature paramagnetic/antiferromagnetic martensite, realizes magnetic structure coupling and has larger magnetic entropy change effect. The magnetic intensity difference before and after the phase change is larger, the magnetic heat effect is enhanced, and the refrigeration is more facilitated.
The material disclosed by the invention has the advantages that the content of R replacing Ni, Co, Mn and Ti is increased, the structural phase transition temperature is regulated and controlled within 100-350K, and the material can work near room temperature.
The magnetic material of the invention has simple preparation process and using equipment, and is beneficial to industrial-grade production.
The transition elements Ni, Co, Mn and Ti used for the magnetic material have low price, rich reserves and easy storage. The doped high-abundance rare earth elements La, Ce and Y have more contents in the rare earth, and the price is relatively low, thereby being beneficial to the effective utilization of the high-abundance rare earth.
The invention is a candidate material of a high-abundance rare earth doped Ni-Co-Mn-Ti based solid magnetic refrigeration material, improves the utilization rate of the high-abundance rare earth, has wider phase change regulation range, can cover room temperature, and can realize magnetic refrigeration application at different temperatures. Therefore, the method has good application prospect.
Drawings
FIG. 1 shows Mn50-a3Ya3Ni30.5Co9.5Ti10XRD pattern of thin band (a3 ═ 0.3,0.5, 0.7);
FIG. 2 shows Mn50-a3Ya3Ni30.5Co9.5Ti10(a3 ═ 0.3,0.5,0.7) M-T plot for thin strip;
FIG. 3 shows Mn49.7Y0.03Ni30.5Co9.5Ti10Magnetic entropy curve of thin band.
Detailed Description
The present invention will now be further described with reference to specific embodiments, which are given by way of illustration and are not intended to limit the scope of the invention.
In the following specific examples, the inventors measured room temperature XRD, thermomagnetic (M-T) curve, isothermal magnetization curve, and magnetic entropy change curve of samples under various processes, respectively, to show the relevant properties of the materials designed by the present invention. For convenience, results are given for only a few samples, with other samples having similar characteristic results.
Example 1:
a magnetic refrigeration material has a chemical formula of Mn50-a3Ya3Ni30.5Co9.5Ti10(a3 ═ 0.3,0.5,0.7), the material preparation method comprising the steps of:
firstly, before proportioning, elements are polished and ground to remove surface scale, and then Mn is adopted50- a3Ya3Ni30.5Co9.5Ti10(a3 is 0.3,0.5,0.7) the raw materials for the preparation in the chemical formula, the purities of Ni, Co, Mn, Ti and Y are all higher than 99.99%, Mn is a volatile element, and 1% is added to compensate the loss in the smelting process.
Then, a water-cooled copper crucible is used for smelting, and circulating water is used for cooling. And (3) putting the prepared raw materials and Ti ingots into the center position of the bottom of the copper crucible, recording the positions of different samples, and closing the furnace to ensure that each valve is in a closed state. Before smelting, the furnace is required to be vacuumized twice: pumping to about 10Pa by a mechanical pump, and then pumping to 3x10 by a molecular pump-3High vacuum of Pa; all valves are closed to ensure that the furnace is an independent vacuum system; finally, high-purity Ar gas with 0.5 atmospheric pressure is filled as protection and arc striking gas. Firstly, igniting an arc on a Ti ingot and smelting for about 1 minute so as to ensure that Ti absorbs residual oxygen in the furnace; then smelting a sample, starting magnetic stirring, and swinging the electric arc head around the sample at a position 2cm above the sample for 45 seconds to enable the surface of the sample to be in a flowing state; after one time of refining, the turn-over is followed by refining according to the method, and each sample is refined for 4 times to ensure the uniformity of the sample.
Finally, the freshly smelted sample is surface ground, the scale is removed and a small spindle of about 3g is cut off. The spindle was placed in a quartz tube with a small hole of 1mm diameter at one end. Putting the quartz tube into an induction coil in a furnace cavity of a melt-spun machine, wherein the end with the small hole is higher than the copper wheelDegree 3 cm. Closing the furnace chamber and vacuumizing twice: pumping to about 10Pa by a mechanical pump, and then pumping to 3x10 by a molecular pump-3Pa of high vacuum. All valves are closed to ensure that the furnace is an independent vacuum system. And finally, filling high-purity Ar gas with 0.5 atmospheric pressure as protective gas. Setting the linear speed of the copper wheel to be 20m/s, melting the cast ingot through high-frequency heating to enable the cast ingot to be completely molten, opening an inflation valve Ar gas to spray the molten material onto the copper wheel rotating at high speed through small holes to obtain a thin strip with the width of 2.5-3.5 mm and the thickness of 10-20 microns.
Example 2:
a magnetic refrigerating material with chemical formula of Ni19Co38-a2Laa2Mn10Ti14(a2 ═ 2,4,6,8), the material preparation method comprising the steps of:
firstly, before proportioning, the elements are polished and grinded to remove surface scale, and then according to Ni19Co38- a2Laa2Mn10Ti14(a2 ═ 2,4,6,8) the raw materials for preparation in the chemical formula, the purity of Ni, Co, Mn, La and Ti is higher than 99.99%, Mn is volatile element, and 1% is added to compensate the loss in the smelting process.
Then, a water-cooled copper crucible is used for smelting, and circulating water is used for cooling. And (3) putting the prepared raw materials and Ti ingots into the center position of the bottom of the copper crucible, recording the positions of different samples, and closing the furnace to ensure that each valve is in a closed state. Before smelting, the furnace is required to be vacuumized twice: pumping to about 10Pa by a mechanical pump, and then pumping to 3x10 by a molecular pump-3Pa of high vacuum. All valves are closed to ensure that the furnace is an independent vacuum system. Finally, high-purity Ar gas with 0.5 atmospheric pressure is filled as protection and arc striking gas. Firstly, arc striking and smelting are carried out on a Ti ingot for about 1 minute, so that the Ti absorbs residual oxygen in the furnace. The sample was then melted, magnetic stirring was turned on, and the arc head was swung around the sample 2cm above the sample for 45 seconds to fluidize the sample surface. After one time of refining, the turn-over is followed by refining according to the method, and each sample is refined for 4 times to ensure the uniformity of the sample.
Finally, the freshly melted sample is surfacedPolished, descaled and cut a small spindle of about 3 g. The spindle was placed in a quartz tube with a small hole of 1mm diameter at one end. And (3) putting the quartz tube into an induction coil in a furnace cavity of the melt-spun machine, wherein the end with the small hole is 3cm away from the copper wheel. Closing the furnace chamber and vacuumizing twice: pumping to about 10Pa by a mechanical pump, and then pumping to 3x10 by a molecular pump-3Pa of high vacuum. All valves are closed to ensure that the furnace is an independent vacuum system. And finally, filling high-purity Ar gas with 0.5 atmospheric pressure as protective gas. Setting the linear speed of the copper wheel to be 20m/s, melting the cast ingot through high-frequency heating to enable the cast ingot to be completely molten, opening an inflation valve Ar gas to spray the molten material onto the copper wheel rotating at high speed through small holes to obtain a thin strip with the width of 3-4.5 mm and the thickness of 10-20 microns.
Example 3:
a magnetic refrigerating material with chemical formula of Ni20Co16Mn29-a3Cea3Ti18.8(a3 ═ 1, 3, 5, 7), the material preparation method comprising the steps of:
firstly, before proportioning, the elements are polished and grinded to remove surface scale, and then according to Ni20Co16Mn29-a3Cea3Ti18.8(a3 ═ 1, 3, 5, 7) the raw materials for preparation in the chemical formula, the purity of Ni, Co, Mn, Ti and Ce is higher than 99.99%, Mn is volatile element, and 1% is added to compensate the loss in the smelting process.
Then, adopting a conventional pulling method to prepare Ni through growth20Co16Mn29-a3Cea3Ti18.8(a3 ═ 1, 3, 5, 7) single crystals: firstly, melting the prepared material placed in a magnetic suspension cold crucible into an ingot with uniform texture by utilizing 245kHz radio frequency, wherein the heating power is 20kW, the heating temperature is 1250 ℃, and the heating time is 20 minutes; then, the ingot having a uniform texture was cut into single crystal grains of 3X10 mm, rotated at a rotation speed of 30 rpm on the surface of the molten raw material and pulled upward at a speed of 30 mm/hour to obtain a single crystal rod of 10mm in diameter and 100mm in length; finally, the obtained single crystal rod is pulled away from the liquid surface and cooled to the room temperature at the speed of 10 ℃/min.
And finally, preserving the temperature of the obtained single crystal rod sample at 1000 ℃ for 100 hours, reducing the temperature to 500 ℃, preserving the temperature for 24 hours, and then cooling at the cooling rate of 10 ℃/second to enable the interior of the material to be more uniform.
Example 4:
a magnetic refrigerating material with chemical formula of Ni20Co25Mn29Ti30-a4Laa4(a4 ═ 5, 7, 9, 11), the material preparation method comprising the steps of:
firstly, before proportioning, the elements are polished and grinded to remove surface scale, and then according to Ni20Co25Mn29Ti30-a4Laa4(a4 ═ 5, 7, 9, 11) formula, the purities of Ni, Co, Mn, Ti and La were all higher than 99.99%, Mn is a volatile element, and 1% more was added to compensate for the loss during the melting process.
Then, preparing Ni by adopting a conventional directional solidification method20Co25Mn29Ti30-a4Laa4(a4 ═ 5, 7, 9, 11) polycrystalline oriented material. The prepared materials in a quartz crucible are melted into an ingot with uniform texture by utilizing 245kHz radio frequency, the heating power is 25kW, the heating temperature is 1400 ℃, and the heating time is 10 minutes. Thereafter, a polycrystalline oriented material having a diameter of 25mm and a length of 150mm was obtained at a growth rate of 30 mm/hr. After that, it was cooled to room temperature at 10 ℃/min.
Finally, the obtained polycrystalline orientation material sample is annealed for 5 hours at 950 ℃, and then cooled at a cooling rate of 20 ℃/minute so that the interior of the material is more uniform.
Example 5:
a magnetic refrigerating material with chemical formula of Ni14(Co36-a2Laa2)Mn40(Ti20-a4Laa4) (a2 ═ 1, 2, 3, 4; a4 ═ 3, 4, 5, 6), the preparation method of the material comprises the following steps:
firstly, before proportioning, the elements are polished and grinded to remove surface scale, and then according to Ni14(Co36- a2Laa2)Mn40(Ti20-a4Laa4)(a2＝1，2，3，4；a4＝3，4，5，6)The purity of the raw materials for preparation in the chemical formula, namely Ni, Co, Mn, Ti and La is higher than 99.99 percent, Mn is a volatile element, and 1 percent is added to compensate the loss in the smelting process.
Then, a water-cooled copper crucible is used for smelting, and circulating water is used for cooling. And (3) putting the prepared raw materials and Ti ingots into the center position of the bottom of the copper crucible, recording the positions of different samples, and closing the furnace to ensure that each valve is in a closed state. Before smelting, the furnace is required to be vacuumized twice: pumping to about 10Pa by a mechanical pump, and then pumping to 3x10 by a molecular pump-3High vacuum of Pa; all valves are closed to ensure that the furnace is an independent vacuum system; finally, high-purity Ar gas with 0.5 atmospheric pressure is filled as protection and arc striking gas; firstly, igniting an arc on a Ti ingot and smelting for about 1 minute so as to ensure that Ti absorbs residual oxygen in the furnace; then smelting a sample, starting magnetic stirring, and swinging the electric arc head around the sample at a position 2cm above the sample for 45 seconds to enable the surface of the sample to be in a flowing state; after one time of refining, the turn-over is followed by refining according to the method, and each sample is refined for 4 times to ensure the uniformity of the sample.
Finally, the ingot obtained by melting was cut into about 3g of blocks, the surface was polished to remove oxide skin, and wrapped with Ti sheets. Putting the quartz tube into the vacuum chamber, vacuumizing and sealing the quartz tube by using a small quartz column to ensure that the quartz tube is vacuum. And (3) putting the quartz tube into a muffle furnace for annealing at 700 ℃, and cooling the furnace after heat preservation for 4 days.
And (3) data analysis:
mn obtained in example 150-a3Ya3Ni30.5Co9.5Ti10The (a3 ═ 0.3,0.5,0.7) thin strip was subjected to a crystal structure test using a Cu target X-ray diffractometer (XRD) at room temperature, and the test pattern thereof is shown in fig. 1, and it was found that the sample was a B2 phase structure and was a single phase. The martensite structure transformation temperature of Y replacing Mn is below room temperature.
FIG. 2 shows Mn obtained in example 150-a3Ya3Ni30.5Co9.5Ti10The thermomagnetic (M-T) curve of the (a3 ═ 0.3,0.5,0.7) thin strip under a 0.1kOe magnetic field measured on a superconducting quantum magnetometer. The phase transition temperature and the Curie temperature of the parent phase of the magnetic structure can be determined from the M-T curve. As can be seen from the figure, temperature hysteresis (about 40K) exists near the phase transition, and the first-order phase transition characteristic is exhibited. All samples underwent a martensitic transformation from ferromagnetic austenite to paramagnetic martensite. The Y replaces Mn, so that the magnetic/structural phase-change coupling is kept, and meanwhile, a large magnetization difference can be obtained, and a large magnetic refrigeration effect is obtained. As the Y substitution increases, the magnetic/structural phase change coupling temperature shifts to a low temperature.
Mn obtained in example 1 was treated with MPMS49.7Y0.3Ni30.5Co9.5Ti10And measuring an isothermal magnetization curve of the thin strip, and calculating a magnetic entropy change curve graph according to a Maxwell formula. FIG. 3 is a graph of magnetic entropy change calculated from isothermal magnetization curves. It can be seen that the magnetic entropy change value is 3.3Jkg under the change of 10kOe magnetic field in the phase transition temperature region-1K-1Under the change of a 70kOe magnetic field, the magnetic entropy change value is 12.6Jkg-1K-1。
According to the invention, the Ni-Co-Mn-Ti-based all-d-metal Heusler alloy is doped with abundant rare earth elements R (La, Ce and Y), so that the magnetization intensity of the alloy can be enhanced, the difference between the magnetization intensity of a parent phase and that of a martensite phase is increased, the generation of magnetic field induced phase transition is promoted, and the magnetocaloric effect is enhanced. The magnetic structure coupling is kept all the time in the doping process, and the phase transition temperature is regulated and controlled near room temperature along with the increase of the content of the high-abundance rare earth elements R (La, Ce and Y). The material of the invention can be applied to magnetic refrigeration in complex environments covering the room temperature range. The invention has better application prospect in the environment of diversified device and equipment response.
Although the present invention has been described by way of preferred embodiments, the present invention is not limited to the embodiments described herein, and various changes and modifications may be made without departing from the scope of the present invention.
Claims (9)
1. A magnetic refrigeration material characterized by: the chemical formula of the material is Nix1-a1Cox2-a2Mnx3-a3Tix4-a4RaWherein x1 is more than or equal to 0 and less than or equal to 50, x2 is more than or equal to 0 and less than or equal to 50, x3 is more than or equal to 0 and less than or equal to 50, and x4 is more than or equal to 0 and less than or equal to 50; r is La or Ce、Y；a1+a2+a3+a4＝a(0＜a≤20)。
2. A magnetic refrigeration material according to claim 1, characterized in that: the phase transition temperature range of the material is 100-350K, and the Curie temperature range is 300-400K.
3. A magnetic refrigeration material according to claim 1 or 2, characterized in that: the maximum magnetic entropy change value of the material is 6.2Jkg under the change of a 0-20 kOe magnetic field-1K-1(ii) a Under the change of a 0-70 kOe magnetic field, the maximum magnetic entropy change value is 12.6Jkg-1K-1。
4. The preparation method of the magnetic refrigeration material is characterized by comprising the following steps of:
(1) weighing high-purity raw materials according to the stoichiometric ratio of the chemical formula, uniformly mixing, wherein Mn is a volatile element, and adding 1% more to compensate loss in the smelting process;
(2) preparing the raw materials into a magnetic phase-change material by adopting an electric arc melting or pulling method or a directional solidification method; arc melting is carried out on the high-purity raw materials under the protection of argon to obtain a block sample;
(3) performing vacuum melt rapid quenching on part of the block sample obtained by arc melting in the step (2) to obtain a thin strip;
(4) and (3) carrying out vacuum annealing heat treatment on the sample in the step (2) or (3) at different temperatures.
5. The method for producing a magnetic refrigeration material according to claim 4, characterized in that: the vacuum degree of the electric arc melting is less than 4 multiplied by 10-3Pa。
6. The method for producing a magnetic refrigeration material according to claim 4, characterized in that: when the pulling method is selected to grow the single crystal, the raw materials in the magnetic suspension cold crucible are heated to 1200-1400 ℃ by adopting radio frequency of 245kHz, the heating power is 20kW, the seed crystal rod is lifted at a uniform speed of 3-80 mm/h by adopting a seed crystal rotation speed of 0-50 rpm, and the single crystal rod with the diameter of 10mm and the length of 100mm is obtained.
7. The method for producing a magnetic refrigeration material according to claim 4, characterized in that: when the polycrystal is prepared by the directional solidification method, the polycrystal is heated to 1350 ℃ by adopting 245kHz radio frequency, the heating power is 25kW, and the polycrystal oriented material with the diameter of 25mm and the length of 150mm is obtained at the growth rate of 30 mm/h.
8. The method for producing a magnetic refrigeration material according to claim 4, characterized in that: the rotation speed of the copper wheel in the preparation process is 10-45m/s, the length of the thin strip thrown out is about 1-20 cm, and the thickness of the thin strip is about 10-35 mu m.
9. The method for producing a magnetic refrigeration material according to claim 4, characterized in that: vacuum degree of less than 1 × 10 during annealing-3Pa, the annealing temperature is 500-1000 ℃, the annealing time is 0-5 days, and furnace cooling treatment or quenching treatment is carried out after the annealing is finished.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011530302.1A CN112760535A (en) | 2020-12-22 | 2020-12-22 | Magnetic refrigeration material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011530302.1A CN112760535A (en) | 2020-12-22 | 2020-12-22 | Magnetic refrigeration material and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112760535A true CN112760535A (en) | 2021-05-07 |
Family
ID=75695128
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011530302.1A Pending CN112760535A (en) | 2020-12-22 | 2020-12-22 | Magnetic refrigeration material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112760535A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1450190A (en) * | 2002-03-26 | 2003-10-22 | 中国科学院物理研究所 | Rereearth-iron base compound magnetic refrigeration material with large magnetic entropy change and preparation process thereof |
| EP2816570A1 (en) * | 2013-06-18 | 2014-12-24 | Karlsruher Institut für Technologie | Reversible alteration of a magnetic state of a material |
| CN105986322A (en) * | 2015-03-03 | 2016-10-05 | 中国科学院物理研究所 | Magnetic phase change material |
| CN109680200A (en) * | 2019-03-18 | 2019-04-26 | 江西理工大学 | A kind of novel Mn base magnetic phase transition alloy and its preparation method and application |
| US20190214169A1 (en) * | 2017-12-28 | 2019-07-11 | Iowa State University Research Foundation, Inc. | Highly tunable, inexpensive and easily fabricated magnetocaloric materials |
| CN111210959A (en) * | 2019-10-25 | 2020-05-29 | 杭州电子科技大学 | Material capable of regulating magnetism and related magnetic effect through bending or twisting and preparation method and application thereof |
-
2020
- 2020-12-22 CN CN202011530302.1A patent/CN112760535A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1450190A (en) * | 2002-03-26 | 2003-10-22 | 中国科学院物理研究所 | Rereearth-iron base compound magnetic refrigeration material with large magnetic entropy change and preparation process thereof |
| EP2816570A1 (en) * | 2013-06-18 | 2014-12-24 | Karlsruher Institut für Technologie | Reversible alteration of a magnetic state of a material |
| CN105986322A (en) * | 2015-03-03 | 2016-10-05 | 中国科学院物理研究所 | Magnetic phase change material |
| US20190214169A1 (en) * | 2017-12-28 | 2019-07-11 | Iowa State University Research Foundation, Inc. | Highly tunable, inexpensive and easily fabricated magnetocaloric materials |
| CN109680200A (en) * | 2019-03-18 | 2019-04-26 | 江西理工大学 | A kind of novel Mn base magnetic phase transition alloy and its preparation method and application |
| CN111210959A (en) * | 2019-10-25 | 2020-05-29 | 杭州电子科技大学 | Material capable of regulating magnetism and related magnetic effect through bending or twisting and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102093850B (en) | High-temperature-stable La(Fe,Si)13-based multi-interstitial-atom hydride magnetic refrigeration material with large magnetic entropy change and preparation method thereof | |
| KR101848520B1 (en) | Magnetocaloric materials | |
| CN109108227B (en) | High-flux preparation method of LaFeSi-based magnetic refrigeration material | |
| CN106917030B (en) | A kind of driving of downfield is orientated Mn-Ni-Sn magnetic refrigeration alloy material and its method for preparing thin strip thereof | |
| US20160256923A1 (en) | Magnetic phase-transformation material | |
| CN110343931A (en) | A kind of room temperature magnetostriction materials and preparation method thereof | |
| CN110970170A (en) | Preparation method of FeTeSe polycrystalline superconductor | |
| TW201113911A (en) | Polycrystalline magnetocaloric materials | |
| CN110534279A (en) | A kind of pure high abundance Rare-Earth Ce, La, the nanocrystalline permanent-magnet alloy of the Quito Y member and preparation | |
| CN108330372B (en) | Ni-Co-Mn-Sn magnetic refrigeration material and preparation method thereof | |
| CN101923933A (en) | Hydrogenated NiMn-based alloy magnetic refrigeration material and preparation method and use thereof | |
| CN105671396B (en) | Terbium germanium antimony material for room temperature magnetic refrigerating and preparation method thereof | |
| CN107574347A (en) | A kind of praseodymium cobalt-base alloys magnetic refrigerating material and its preparation method and application | |
| CN107393670A (en) | A kind of high-performance MnBi base permanent magnetic alloys and preparation method thereof | |
| CN112760535A (en) | Magnetic refrigeration material and preparation method thereof | |
| CN103668008A (en) | Thulium-based metal glass, preparation method and application thereof | |
| CN109576530B (en) | Giant exchange bias Mn-based alloy and preparation method and application thereof | |
| CN100489137C (en) | Rare earth-iron-silicon base compound having primary magnetic phase change characteristics and its preparation method | |
| CN105861860B (en) | A kind of terbium germanium bismuth material, preparation method and applications | |
| CN112216458A (en) | Material for enhancing magnetocaloric effect and preparation method thereof | |
| CN107267839B (en) | A kind of room temperature magnetic refrigerating alloy magneto-caloric material and the preparation method and application thereof | |
| CN108286004A (en) | A kind of rare earth-nickel-aluminum material, preparation method and applications | |
| CN117637274B (en) | Rare earth-iron-silicon magnetic refrigeration material with low magnetic field, preparation method and application | |
| CN110453132B (en) | Ni-Mn-Sn-Co-Si magnetic refrigeration material | |
| CN110172631B (en) | Cobalt-manganese-tin-based alloy material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210507 |
|
| RJ01 | Rejection of invention patent application after publication |