Method for improving physical properties of Mn2Sb-based alloy material with rich Bi phase

Abstract

The application belongs to the technical field of magnetic phase change materials, and particularly relates to a method for improving the physical performance of a Bi-rich phase Mn2Sb-based alloy material, which comprises the following steps: mixing a parent phase alloy with a diffusion source, sintering, and diffusing the diffusion source into the parent phase alloy to obtain a Bi-rich phase Mn2Sb-based alloy material; the diffusion source accounts for 2.9% to 30% of the total mass of the parent phase alloy and the diffusion source; the diffusion source is Dy 100‑y Cu y , 5<=y<=40 or Pr 100‑z Ga z , 5<=z<=40; the parent phase alloy is (Mn2Sb) 1‑x Bi x , 0 The application diffuses rare earth alloy to the grain boundary phase of the Bi-rich phase Mn2Sb-based alloy to optimize the magnetic performance of the material, so that the material can be widely applied to magnetic memories, magnetic drivers, magnetic sensors, thermomagnetic electric conversion devices, solid-state refrigeration devices and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of magnetic phase change materials, and particularly relates to a method for improving the physical properties of a Bi-rich Mn2Sb-based alloy material. BACKGROUND

[0002] Mn atoms have good magnetic moments and also have the advantages of low cost, and among these Mn-based intermetallic compounds, the magnetic phase change material Mn2Sb-based alloy stands out. This new type of magnetic functional material exhibits many rich and application-valued physical properties and effects, such as dynamic confinement, spin reorientation, giant magnetocaloric effect, giant magnetoresistance effect, exchange bias effect and Hall effect, and has important applications in some basic research fields of phase change physics, as well as in the fields of smart materials, information storage, magnetic refrigeration and other frontiers.

[0003] The Mn2Sb-based alloy has rich physical properties and effects, but its physical properties are not excellent. The performance of the Mn2Sb-based alloy, especially the magnetic performance, can be improved by adding magnetic rare earth elements. However, in the process of doping Bi elements, the Mn2Sb-based alloy has obvious Bi-rich grain boundary phases, and the grain boundary phases may agglomerate during the diffusion of Bi elements. The agglomeration phenomenon will seriously affect the magnetic performance of the Bi-rich Mn2Sb-based alloy. SUMMARY

[0004] To solve the above technical problems, the application provides a method for improving the physical properties of a Bi-rich Mn2Sb-based alloy material, which improves the magnetic performance of the Bi-rich Mn2Sb-based alloy material by introducing a diffusion source.

[0005] The application provides a method for improving the physical properties of a Bi-rich Mn2Sb-based alloy material, wherein the physical properties are magnetic properties, and the method comprises the following steps:

[0006] Mixing the parent phase alloy with the diffusion source, sintering at 500-850 DEG C for 15-36 min, so that the diffusion source diffuses into the parent phase alloy;

[0007] The diffusion source accounts for 2.9-30% of the total mass of the parent phase alloy and the diffusion source;

[0008] The diffusion source is Dy 100-y Cu y , 5<=y<=40 or Pr 100-z Ga z , 5<=z<=40;

[0009] The parent phase alloy is (Mn2Sb) 1-x Bi x , 0

[0010] wherein x, y, z represent atomic percentage content.

[0011] The application diffuses the rare earth alloy to the material grain boundary phase by mixing the diffusion source with the matrix alloy, controlling the diffusion source Dy 100-y Cu y or Pr 100-z Ga z The mass percentage of the diffusion source is 2.9% to 30%, the rare earth alloy is diffused to the material grain boundary phase, and the magnetic grain boundary phase is obtained in the (Mn2Sb) 1-x Bi x alloy. Sintering at 500℃ to 850℃ for 15min to 36min can make the diffusion source better diffuse in the matrix alloy, thereby further improving the magnetic properties of the Bi-rich phase Mn2Sb-based alloy material. 1-x Bi x 0

[0012] In another preferred embodiment, the sintering is followed by heat treatment.

[0013] The heat treatment refers to annealing at the sintering temperature for 1 day to 5 days and then cooling to 21℃ to 25℃. Through the heat treatment, the purpose of uniform diffusion is achieved.

[0014] In another preferred embodiment, the sintering pressure is 15Mpa to 100Mpa.

[0015] In another preferred embodiment, the particle size of the matrix alloy is 10μm to 50μm, and the particle size of the diffusion source is 1μm to 50μm.

[0016] In another preferred embodiment, the specific preparation process of the matrix alloy is as follows:

[0017] According to the stoichiometric ratio, the matrix alloy raw materials Mn, Sb and Bi are weighed respectively, mixed and then melted to obtain the (Mn2Sb) 1-x Bi x ingot, the (Mn2Sb) 1-x Bi x ingot is annealed and crushed to obtain the matrix alloy.

[0018] The specific preparation process of the diffusion source is as follows:

[0019] According to the stoichiometric ratio, the diffusion source raw materials Dy and Cu, or Pr and Ga are weighed respectively, mixed, and then melted to obtain the diffusion source Dy 100-y Cuy ingot or Pr 100-z Ga z ingot;

[0020] Dy 100-y Cu y ingot or Pr 100-z Ga z ingot is melted into liquid state and sprayed onto a rotating copper roll to obtain Dy 100- y Cu y rapidly-quenched strip or Pr 100-z Ga z rapidly-quenched strip, Dy 100-y Cu y rapidly-quenched strip or Pr 100-z Ga z The rapidly-quenched strip is crushed to obtain the diffusion source.

[0021] In another preferred embodiment, the melting temperature during preparation of the parent phase alloy is 950-1000℃, the annealing temperature is 680-700℃, and the annealing time is 5-7d;

[0022] The melting temperature of the diffusion source preparation process is 800-900℃.

[0023] In another preferred embodiment, the crushing is performed by grinding or ball milling.

[0024] In another preferred embodiment, the grinding time is 30-60min.

[0025] In another preferred embodiment, the ball milling is performed at a forward-reverse rotation speed of 200-500rpm for 40-60min, with 5-10 cycles.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] (1) The present application can make the rare earth element diffusion source better diffuse into (Mn2Sb) 1-x Bi x parent phase alloy by introducing the rare earth element diffusion source Dy 100-y Cu y or Pr 100-z Ga z , and controlling the sintering temperature, so that the rare earth element diffusion source can better diffuse into (Mn2Sb) 1-x Bi xIn the parent phase alloy, the phase transformation thermal hysteresis is significantly reduced after diffusion, thereby effectively improving the magnetic properties of the Bi-rich Mn2Sb-based alloy material. The Bi-rich Mn2Sb-based alloy material obtained through grain boundary diffusion of rare earth elements possesses a magnetic grain boundary phase, further enhancing its magnetic properties and making it more promising for a wider range of applications. Furthermore, the (Mn2Sb) in this invention... 1- x Bi x For alloys with 0 < x ≤ 0.2, the number of alloy components and Bi-rich grain boundary phases can be adjusted by changing the value of x, thereby achieving controllable grain boundary channels, regulating grain boundary diffusion channels, and promoting the diffusion of rare earth elements.

[0028] (2) The method in this invention enables Bi-rich Mn2Sb-based alloy materials to have multifunctional properties, including giant magnetocaloric effect, giant magnetoresistance effect, exchange bias effect and Hall effect, which can then be widely used in some basic research fields of phase transition physics as well as potential application fields such as smart materials, information storage, magnetic refrigeration / heating. Attached Figure Description

[0029] Figure 1 This refers to the alloy diffusion (Mn2Sb) in Example 1 of the present invention. 0.89 Bi 0.11 The horizontal iso-field thermomagnetic curves of the alloy sample are shown in the figure. ZFC represents the zero-field cooling curve and FC represents the field cooling curve.

[0030] Figure 2 Dy in Embodiment 1 of the present invention 70 Cu 30 Alloy diffusion (Mn2Sb) 0.89 Bi 0.11 Vertical iso-field thermomagnetic curves of the alloy sample.

[0031] Figure 3 Dy in Embodiment 1 of the present invention 70 Cu 30 Alloy diffusion (Mn2Sb) 0.89 Bi 0.11 EDS point scan images of the alloy samples, where 1.txt, 2.txt, 3.txt, 4.txt, and 5.txt represent the scan locations.

[0032] Figure 4 Dy in Embodiment 1 of the present invention 70 Cu 30 Alloy diffusion (Mn2Sb) 0.89 Bi 0.11 Iso-field thermomagnetic curves of the alloy sample before and after diffusion.

[0033] Figure 5Dy in Embodiment 2 of the present invention 70 Cu 30 Alloy diffusion (Mn2Sb) 0.89 Bi 0.11 EDS spot scan of the alloy sample.

[0034] Figure 6 In Embodiment 3 of the present invention, Pr 80 Ga 20 Alloy diffusion (Mn2Sb) 0.89 Bi 0.11 EDS spot scan of the alloy sample. Detailed Implementation

[0035] The present invention will be described in detail below with reference to specific embodiments, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following embodiments can be obtained commercially unless otherwise specified.

[0036] This invention utilizes an in-situ grain boundary diffusion method in (Mn2Sb) 1-x Bi x In alloys where 0 < x ≤ 0.2, a diffusion source Dy containing rare earth elements is introduced. 100-y Cu y or Pr 100-z Ga z The diffusion source Dy is made more soluble through calcination and heat treatment. 100-y Cu y or Pr 100- z Ga z In (Mn2Sb) 1-x Bi x Diffusion occurs in the matrix, forming new grain boundary phases, thereby improving the magnetic properties of the alloy. The method of this invention can yield a Bi-rich Mn2Sb-based alloy material with excellent magnetic properties, wherein the specific composition of the parent phase alloy and the diffusion source is as follows:

[0037] Parent phase alloy (Mn2Sb) 1-x Bi x x = 0.09 and the diffusion source Dy 100-y Cu y y = 5, and the diffusion source accounts for 2.9% of the total mass of the parent phase alloy and the diffusion source.

[0038] Parent phase alloy (Mn2Sb) 1-x Bi x x = 0.09 and the diffusion source Dy 100-y Cu y y = 5, and the diffusion source accounts for 4.8% of the total mass of the parent phase alloy and the diffusion source.

[0039] parent alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Dy 100-y Cu y y = 30, the diffusion source representing 2.9% of the total mass of the parent alloy and diffusion source.

[0040] parent alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Dy 100-y Cu y y = 30, the diffusion source representing 4.8% of the total mass of the parent alloy and diffusion source.

[0041] parent alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Dy 100-y Cu y y = 40, the diffusion source representing 2.9% of the total mass of the parent alloy and diffusion source.

[0042] parent alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Dy 100-y Cu y y = 40, the diffusion source representing 4.8% of the total mass of the parent alloy and diffusion source.

[0043] parent alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Pr 100-z Ga z z = 5, the diffusion source representing 2.9% of the total mass of the parent alloy and diffusion source.

[0044] parent alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Pr 100-z Ga z z = 5, the diffusion source representing 4.8% of the total mass of the parent alloy and diffusion source.

[0045] parent alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Pr 100-z Ga z z = 20, the diffusion source representing 2.9% of the total mass of the parent alloy and diffusion source.

[0046] parent alloy (Mn2Sb) 1-x Bix x = 0.09 and diffusion source Pr 100-z Ga z z = 20, the diffusion source accounts for 4.8% of the total mass of the matrix alloy and the diffusion source.

[0047] Matrix alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Pr 100-z Ga z z = 40, the diffusion source accounts for 2.9% of the total mass of the matrix alloy and the diffusion source.

[0048] Matrix alloy (Mn2Sb) 1-x Bi x x = 0.09 and diffusion source Pr 100-z Ga z z = 40, the diffusion source accounts for 4.8% of the total mass of the matrix alloy and the diffusion source.

[0049] In the above alloys, the x of Bi in Mn2Sb is 0.09, mainly because the limit of solubility of Bi in Mn2Sb is 7% to 9%, so the Bi selected in the present application is 0.09, which is the limit value in Mn2Sb.

[0050] Matrix alloy (Mn2Sb) 1-x Bi x x = 0.11 and diffusion source Dy 100-y Cu y y = 30, the diffusion source accounts for 2.9% of the total mass of the matrix alloy and the diffusion source.

[0051] Matrix alloy (Mn2Sb) 1-x Bi x x = 0.11 and diffusion source Dy 100-y Cu y y = 30, the diffusion source accounts for 4.8% of the total mass of the matrix alloy and the diffusion source.

[0052] Matrix alloy (Mn2Sb) 1-x Bi x x = 0.11 and diffusion source Pr 100-z Ga z z = 20, the diffusion source accounts for 2.9% of the total mass of the matrix alloy and the diffusion source.

[0053] Matrix alloy (Mn2Sb) 1-x Bi x x = 0.11 and diffusion source Pr 100-z Ga z z = 20, the diffusion source accounts for 4.8% of the total mass of the matrix alloy and the diffusion source.

[0054] Parent alloy (Mn2Sb) 1-x Bi x x = 0.2 with diffusion source Dy 100-y Cu y y = 30, the diffusion source accounts for 2.9% of the total mass of the parent alloy and diffusion source.

[0055] Parent alloy (Mn2Sb) 1-x Bi x x = 0.2 with diffusion source Dy 100-y Cu y y = 30, the diffusion source accounts for 4.8% of the total mass of the parent alloy and diffusion source.

[0056] Parent alloy (Mn2Sb) 1-x Bi x x = 0.2 with diffusion source Pr 100-z Ga z z = 20, the diffusion source accounts for 2.9% of the total mass of the parent alloy and diffusion source.

[0057] Parent alloy (Mn2Sb) 1-x Bi x x = 0.2 with diffusion source Pr 100-z Ga z z = 20, the diffusion source accounts for 4.8% of the total mass of the parent alloy and diffusion source.

[0058] The above are the two end limit values of 0% ~ 0.2% of Bi in the Bi-rich Mn2Sb-based alloy.

[0059] Parent alloy (Mn2Sb) 1-x Bi x x = 0.11 with rare earth alloy diffusion source Dy 100-y Cu y y = 30, the diffusion source accounts for 10% of the total mass of the parent alloy and diffusion source.

[0060] Parent alloy (Mn2Sb) 1-x Bi x x = 0.11 with diffusion source Dy 100-y Cu y y = 30, the diffusion source accounts for 20% of the total mass of the parent alloy and diffusion source.

[0061] Parent alloy (Mn2Sb) 1-x Bi x x = 0.11 with diffusion source Dy 100-y Cu y y = 30, the diffusion source accounts for 30% of the total mass of the parent alloy and diffusion source.

[0062] The diffusion source value-added limit is 2.9% to 30%.

[0063] Based on the above principle, the application provides the Mn2Sb-based alloy material with the Bi-rich phase and good magnetic performance, and the following five methods for improving the physical performance of the Mn2Sb-based alloy material with the Bi-rich phase are taken as examples for illustration.

[0064] Embodiment 1

[0065] A method for improving the physical performance of the Mn2Sb-based alloy material with the Bi-rich phase, wherein the magnetic phase change alloy (Mn2Sb) 0.89 Bi 0.11 is a parent phase, and the diffusion source is Dy 70 Cu 30 and comprises the following steps:

[0066] S1. The mass of Mn, Sb, Bi, Dy and Cu element simples required is calculated according to the stoichiometric ratio, and the ingredients are prepared, and the mass of the element simples needs to be accurate to three decimal places in milligram units, the purity of Mn and Dy simples is 99.8%, and the purity of other simples is 99.99% through arc melting for purification.

[0067] S2. The elements Mn, Sb and Bi in S1 are put into a 950℃ high vacuum melting furnace, the furnace cavity is vacuumized to 5×10 - 3 Pa, 0.5 atmospheres of argon gas are introduced, an electric arc is released through a tungsten electrode, the above-mentioned metal raw materials are melted into a liquid state by using a 100A current, and reciprocation is performed four times to obtain (Mn2Sb) 0.89 Bi 0.11 ingot.

[0068] The elements Dy and Cu in S1 are put into a 950℃ high vacuum melting furnace, the furnace cavity is vacuumized to 5×10 -3 Pa, 0.5 atmospheres of argon gas are introduced, an electric arc is released through a tungsten electrode, the above-mentioned metal raw materials are melted into a liquid state by using a 100A current, and reciprocation is performed four times to obtain Dy 70 Cu 30 ingot.

[0069] S3. The obtained (Mn2Sb) 0.89 Bi 0.11 alloy ingot is annealed at 700℃ for 5 days, and then water quenched to obtain a (Mn2Sb) 0.89 Bi 0.11 bulk body.

[0070] S4. The Dy 70 Cu 30The ingot was put into a quartz tube with an inner diameter of 10 mm and an opening diameter of 1 mm, and the quartz tube was put into a high-vacuum spinning furnace, the furnace cavity was vacuumized to 10 -4 Pa, 0.5 atm of argon was introduced, the rotating speed of the copper roller was adjusted to 24 m / s, the heating current of the induction coil was adjusted, when the current reached 36 A or above, the alloy ingot was observed to be red, the current was continuously increased to 41 ± 3 A, the alloy ingot was in a liquid state and flowed, the molten alloy was sprayed onto the rotating copper roller by air pressure difference to rapidly solidify and form a rapidly quenched strip, and Dy 70 Cu 30 strip.

[0071] S5, (Mn2Sb) 0.89 Bi 0.11 bulk and Dy 70 Cu 30 and the strip was preliminarily ground with a mortar, and then was ground for 60 min at 50 Hz by a vibration ball mill, to obtain (Mn2Sb) 0.89 Bi 0.11 powder with a particle size of 300 mesh. 70 Cu 30 powder.

[0072] S6, Dy 70 Cu 30 powder was mixed with (Mn2Sb) 0.89 Bi 0.11 powder, to obtain a mixed powder, wherein the diffusion source accounts for 4.8% of the total mass of the parent phase alloy and the diffusion source; the mixed powder was added to a graphite mold, and diffusion was performed by using a plasma discharge sintering furnace, sintering at a temperature of 800 ℃ for 15 min, a pressure of 100 MPa, a holding time of 8 min, a pressure holding time of 2 min, annealing at the sintering temperature in a muffle furnace for 5 days, and then cooling to 21 ℃ in the furnace.

[0073] Example 2

[0074] A method for improving the physical properties of a Bi-rich phase Mn2Sb-based alloy material, the method comprising the following steps: 0.89 Bi 0.11 as a parent phase, and a diffusion source of Dy 70 Cu 30 .

[0075] S1, the mass of the required Mn, Sb, Bi, Dy, and Cu elements was calculated according to the stoichiometric ratio, and the ingredients were prepared, the mass of the element was required to be accurate to the third decimal place in milligram units, the purity of Mn and Dy elements was 99.8%, and the other elements were purified by arc melting, and the purity of the other elements was 99.99%.

[0076] S2, put the elements Mn, Sb, Bi in S1 into a 1000℃ high vacuum smelting furnace, vacuumize the furnace cavity to 5x10 - 3 Pa, pass in 0.5 atmospheres of argon, release an electric arc through a tungsten electrode, melt the above-mentioned metal raw materials into a liquid state with a 100A current, reciprocate 4 times, and obtain (Mn2Sb) 0.89 Bi 0.11 ingot.

[0077] S1, put the elements Dy, Cu into a 950℃ high vacuum smelting furnace, vacuumize the furnace cavity to 5x10 -3 Pa, pass in 0.5 atmospheres of argon, release an electric arc through a tungsten electrode, melt the above-mentioned metal raw materials into a liquid state with a 100A current, reciprocate 4 times, and obtain Dy 70 Cu 30 ingot.

[0078] S3, anneal the obtained (Mn2Sb) 0.89 Bi 0.11 alloy ingot at 680℃ for 7 days, then water quench, and obtain (Mn2Sb) 0.89 Bi 0.11 bulk.

[0079] S4, put the Dy 70 Cu 30 ingot into a quartz tube with an inner diameter of 10mm and an opening diameter of 1mm, place the quartz tube into a high vacuum spinning furnace, vacuumize the furnace cavity to 10 -4 Pa, pass in 0.5 atmospheres of argon, adjust the copper roller rotation speed to 24m / s, adjust the induction coil heating current, and when the current reaches 36A or above, observe that the alloy ingot is red, continue to increase the current to 41±3A, and the alloy ingot is in a liquid state and flows, use air pressure difference to spray the molten alloy onto the rotating copper roller to rapidly solidify and form a rapidly quenched strip, and obtain Dy 70 Cu 30 strip.

[0080] S5, put the (Mn2Sb) 0.89 Bi 0.11 bulk and Dy 70 Cu 30 and strip into a mortar and grind preliminarily, then pass through a vibration ball mill and grind for 60min at 50Hz, and obtain (Mn2Sb) 0.89 Bi 0.11 powder with a particle size of 500 mesh and Dy 70 Cu 30 powder with a particle size of 300 mesh.

[0081] S6, put the Dy 70 Cu 30powder and (Mn2Sb) 0.89 Bi 0.11 The powders are mixed to obtain a mixed powder, wherein the diffusion source accounts for 2.9% of the total mass of the parent phase alloy and the diffusion source; the mixed powder is added to a graphite mold, diffusion is performed using a plasma discharge sintering furnace, the sintering temperature is 600℃, the sintering time is 36min, the pressure is 50Mpa, the holding time is 8min, and the holding time is 2min, to obtain a Bi-rich phase Mn2Sb-based alloy material, the sintering temperature is maintained in an annealing muffle furnace for 4 days, and then the furnace is cooled to 21℃.

[0082] Example 3

[0083] A method for improving the physical properties of a Bi-rich phase Mn2Sb-based alloy material, a magnetic phase change alloy (Mn2Sb) 0.89 Bi 0.11 The parent phase is Pr 80 Ga 20 , comprising the following steps:

[0084] S1, the mass of the required Mn, Sb, Bi, Dy, Cu element single substance is calculated according to the stoichiometric ratio, and the ingredients are prepared, the mass of the element single substance needs to be accurate to the three decimal places of the milligram unit, the purity of Mn and Dy single substance is 99.8%, which is purified by arc melting, and the purity of other single substances is 99.99%.

[0085] S2, the elements Mn, Sb and Bi in S1 are put into a 950℃ high vacuum melting furnace, the furnace cavity is vacuumized to 5×10 - 3 Pa, 0.5atm of argon gas is introduced, an electric arc is released through a tungsten electrode, and the above-mentioned metal raw materials are melted into a liquid state by using a 100A current, which is reciprocated 4 times to obtain (Mn2Sb) 0.89 Bi 0.11 ingot;

[0086] The elements Dy and Cu in S1 are put into a 950℃ high vacuum melting furnace, the furnace cavity is vacuumized to 5×10 -3 Pa, 0.5atm of argon gas is introduced, an electric arc is released through a tungsten electrode, and the above-mentioned metal raw materials are melted into a liquid state by using a 100A current, which is reciprocated 4 times to obtain Dy 70 Cu 30 ingot.

[0087] S3, the obtained (Mn2Sb) 0.89 Bi 0.11 alloy ingot is annealed at 700℃ for 5 days, and then water quenched to obtain a (Mn2Sb) 0.89 Bi 0.11 bulk.

[0088] S4, Dy 70 Cu 30 The ingot was put into a quartz tube with an inner diameter of 10 mm and an opening diameter of 1 mm, and the quartz tube was put into a high-vacuum spinning furnace. The furnace cavity was evacuated to 10 -4 Pa, 0.5 atm of argon was introduced, the rotation speed of the copper roller was adjusted to 24 m / s, the heating current of the induction coil was adjusted, and when the current reached 36 A or more, the alloy ingot was observed to be red. The current was continuously increased to 41±3 A, and the alloy ingot was in a liquid state and flowed. The molten alloy was sprayed onto the rotating copper roller by air pressure difference to rapidly solidify and form a rapidly quenched strip. Dy 70 Cu 30 strip.

[0089] S5, (Mn2Sb) 0.89 Bi 0.11 bulk and Dy 70 Cu 30 and the strip was preliminarily ground with a mortar, and then ground for 60 min at 50 Hz by a vibration ball mill, to obtain (Mn2Sb) 0.89 Bi 0.11 powder with a particle size of 500 mesh and Dy 70 Cu 30 powder with a particle size of 300 mesh.

[0090] S6, Dy 70 Cu 30 powder was mixed with (Mn2Sb) 0.89 Bi 0.11 powder, to obtain a mixed powder, wherein the diffusion source accounts for 2.9% of the total mass of the parent phase alloy and the diffusion source. The mixed powder was added to a graphite mold, and diffusion was performed using a plasma discharge sintering furnace. The sintering temperature was 600°C, the sintering time was 20 min, the pressure was 50 MPa, the holding time was 8 min, and the pressure holding time was 2 min. A Bi-rich phase Mn2Sb-based alloy material was obtained. The sintering temperature was maintained in a muffle furnace for annealing for 5 days, and then the furnace was cooled.

[0091] Example 4

[0092] A method for improving the physical properties of a Bi-rich phase Mn2Sb-based alloy material, a magnetic phase change alloy (Mn2Sb) 0.89 Bi 0.11 is a parent phase, and a diffusion source is Dy 70 Cu 30 , comprising the following steps:

[0093] S1, the mass of Mn, Sb, Bi, Dy, Cu element substance required is calculated according to the stoichiometric ratio, and the ingredients are prepared, the mass of the element substance needs to be accurate to the three decimal places of the milligram unit, the purity of Mn and Dy element is 99.8%, which is purified by arc melting, and the purity of other elements is 99.99%.

[0094] S2, the elements Mn, Sb, Bi in S1 are put into a 950℃ high vacuum melting furnace, the furnace cavity is vacuumized to 5×10 - 3 Pa, 0.5 atmosphere of argon is introduced, an electric arc is released by a tungsten electrode, the above-mentioned metal raw materials are melted into a liquid state by a current of 150A, reciprocated 4 times, and (Mn2Sb) 0.89 Bi 0.11 ingot is obtained.

[0095] The elements Dy, Cu in S1 are put into a 950℃ high vacuum melting furnace, the furnace cavity is vacuumized to 5×10 -3 Pa, 0.5 atmosphere of argon is introduced, an electric arc is released by a tungsten electrode, the above-mentioned metal raw materials are melted into a liquid state by a current of 150A, reciprocated 4 times, and Dy 70 Cu 30 ingot is obtained.

[0096] S3, the obtained (Mn2Sb) 0.89 Bi 0.11 alloy ingot is annealed at 700℃ for 5 days, and then water quenched, and (Mn2Sb) 0.89 Bi 0.11 bulk is obtained.

[0097] S4, the Dy 70 Cu 30 ingot is put into a quartz tube with an inner diameter of 10mm and an opening diameter of 1mm, the quartz tube is put into a high vacuum spinning furnace, the furnace cavity is vacuumized to 10 -4 Pa, 0.5 atmosphere of argon is introduced, the rotating speed of the copper roller is adjusted to 24m / s, the heating current of the induction coil is adjusted, when the current reaches 36A or more, the alloy ingot is observed to be red, the current is continuously increased to 41±3A, the alloy ingot is in a liquid state and flows, the molten alloy is sprayed onto the rotating copper roller by air pressure difference to quickly solidify and form a rapidly quenched strip, and Dy 70 Cu 30 strip is obtained.

[0098] S5, the (Mn2Sb) 0.89 Bi 0.11 bulk and Dy 70 Cu 30and the strip was preliminarily ground with a mortar, and then was ground by a vibration ball mill for 60 min at 50 Hz to obtain a powder with a particle size of 500 mesh (Mn2Sb) 0.89 Bi 0.11 and a powder with a particle size of 300 mesh (Dy) 70 Cu 30 powder.

[0099] S6, Dy 70 Cu 30 powder and (Mn2Sb) 0.89 Bi 0.11 The mixed powder was obtained by mixing the powders, wherein the diffusion source accounted for 4.8% of the total mass of the matrix alloy and the diffusion source; the mixed powder was added into a graphite mold, and diffusion was performed by using a plasma discharge sintering furnace, the sintering temperature was 800°C, the sintering time was 25 min, the pressure was 50 MPa, the holding time was 8 min, the holding pressure time was 2 min, the sintering temperature was maintained in the muffle furnace for annealing for 4 days, and then the furnace was cooled to 21°C.

[0100] Example 5

[0101] A method for improving the physical properties of a Bi-rich phase Mn2Sb-based alloy material, the magnetic phase change alloy (Mn2Sb) 0.89 Bi 0.11 The matrix was a matrix, and the diffusion source was Dy 70 Cu 30 and the following steps were included:

[0102] S1, the mass of the required Mn, Sb, Bi, Dy, and Cu elements was calculated according to the stoichiometric ratio, and the ingredients were prepared, the mass of the element needed to be accurate to the third decimal place in milligram units, the purity of the Mn and Dy elements was 99.8%, and the purity of the other elements was 99.99%.

[0103] S2, the elements Mn, Sb, and Bi in S1 were put into a 950°C high-vacuum melting furnace, the furnace cavity was vacuumed to 5×10 - 3 Pa, 0.5 atmospheres of argon gas were introduced, an electric arc was released by a tungsten electrode, the above-mentioned metal raw materials were melted into a liquid state by using a 100A current, and reciprocation was performed 4 times to obtain (Mn2Sb) 0.89 Bi 0.11 ingot;

[0104] The elements Dy and Cu in S1 were put into a 950°C high-vacuum melting furnace, the furnace cavity was vacuumed to 5×10 -3 Pa, 0.5 atmospheres of argon gas were introduced, an electric arc was released by a tungsten electrode, the above-mentioned metal raw materials were melted into a liquid state by using a 100A current, and reciprocation was performed 4 times to obtain Dy 70 Cu30 Ingot.

[0105] S3, the obtained (Mn2Sb) 0.89 Bi 0.11 The alloy ingot was annealed at 700℃ for 6 days, and then water quenched to obtain (Mn2Sb) 0.89 Bi 0.11 Bulk.

[0106] S4, Dy 70 Cu 30 The ingot was put into a quartz tube with an inner diameter of 10 mm and an opening diameter of 1 mm, and the quartz tube was put into a high vacuum tape casting furnace. The furnace cavity was vacuumed to 10 -4 Pa, and 0.5 atm of argon gas was introduced. The copper roller speed was adjusted to 24 m / s, and the inductive coil heating current was adjusted. When the current reached 36 A or more, the alloy ingot was observed to be red. The current was continued to be increased to 41±3 A, and the alloy ingot was in a liquid state and flowed. The molten alloy was sprayed onto the rotating copper roller by air pressure difference to rapidly solidify and form a rapidly quenched strip. Dy 70 Cu 30 Strip.

[0107] S5, (Mn2Sb) 0.89 Bi 0.11 Bulk and Dy 70 Cu 30 The ingot was put into a quartz tube with an inner diameter of 10 mm and an opening diameter of 1 mm, and the quartz tube was put into a high vacuum tape casting furnace. The furnace cavity was vacuumed to 10 0.89 Bi 0.11 Powder and Dy 70 Cu 30 Powder.

[0108] S6, Dy 70 Cu 30 Powder was mixed with (Mn2Sb) 0.89 Bi 0.11 Powder to obtain a mixed powder, wherein the diffusion source accounts for 4.8% of the total mass of the parent phase alloy and the diffusion source; the mixed powder was added to a graphite mold, and diffusion was carried out using a plasma discharge sintering furnace, with a sintering temperature of 770℃ for 15 min, a pressure of 50 Mpa, a holding time of 8 min, and a pressure holding time of 2 min. A Bi-rich phase Mn2Sb-based alloy material was obtained. The sintering temperature was maintained in an annealing muffle furnace for 4 days, and then cooled to 21℃ in the furnace.

[0109] (Mn2Sb) 0.89 Bi 0.11 The diffusion source in the middle was Dy 70 Cu 30The measurement was carried out, wherein Dy 70 Cu 30 4.8% of the total mass of the parent phase alloy and the diffusion source, and the results are shown in Figures 1 to 4

[0110] By Figure 1 and Figure 2 It can be seen that (Mn2Sb) 0.89 Bi 0.11 The diffusion source is Dy 70 Cu 30 When, whether it is a horizontal cross section or a vertical cross section, the parent phase and the diffusion source can be mixed uniformly, and the thermomagnetic curve under the magnetic field of 0.01T and 5T has no obvious deviation, and there is a phase change at low temperature, which is the magnetic change caused by the grain boundary diffusion of rare earth alloy, and according to Table 1 and Figure 3 It can be seen that in the eds point scanning, the composition of the second point can explain that the rare earth element Dy diffuses along the grain boundary, and in Figure 4 It can be seen that after diffusion, the phase change hysteresis is greatly reduced, which shows that the grain boundary diffusion of rare earth elements is beneficial to improve the magnetic properties of the alloy.

[0111] Table 1 The composition of the position of the eds point scanning in (Mn2Sb) 0.89 Bi 0.11 The diffusion source Dy 70 Cu 30 of Example 1

[0112] Scan point Mn (at%) Cu (at%) Sb (at%) Dy (at%) Bi (at%) 1 40.87 0.04 29.90 20.91 8.27 2 14.55 0.00 8.48 41.81 35.17 3 61.85 1.03 34.86 0.05 2.21 4 66.20 0.91 30.16 0.24 2.49 5 5.98 0.00 36.97 45.72 11.32 6 60.47 0.47 29.75 5.23 4.09

[0113] The measurement was carried out on (Mn2Sb) 0.89 Bi 0.11 The diffusion source is Dy 70 Cu 30 , wherein Dy 70 Cu 30 2.9% of the total mass of the parent phase alloy and the diffusion source, and the results are shown in Figure 5

[0114] By Figure 5 and position 1 and 2 in Table 2, it can be seen that there is partial diffusion between the Dy 70 Cu 30 alloy and the Bi-rich phase, which shows that the method of diffusing rare earth alloy along the original Bi-rich grain boundary is feasible, and positions 3 and 4 show that the interior of the large particle Dy 70 Cu 30 did not diffuse during the diffusion process, and in combination with Figure 3 ​​And the Cu atomic distribution and agglomeration of Table 1, it can be explained that the temperature of 600℃ has caused the diffusion of part of rare earth elements, which proves that the obvious diffusion phenomenon can also occur below the melting point temperature of rare earth alloy, i.e. 790℃.

[0115] Table 2 (Mn2Sb) in Example 2 0.89 Bi 0.11 Dy in the middle of the diffusion source 70 Cu 30 The composition of EDS point scanning position

[0116] Scan point Mn (at%) Cu (at%) Sb (at%) Dy (at%) Bi (at%) 1 4.69 0.00 21.92 56.93 16.47 2 6.67 0.00 14.18 62.26 16.88 3 0.73 29.87 0.15 68.97 0.29 4 0.38 25.62 0.08 73.93 0.00 5 64.10 0.35 34.63 0.00 0.92 6 65.27 0.43 33.33 0.00 0.97

[0117] (Mn2Sb) obtained in Example 3 0.89 Bi 0.11 Pr in the middle of the diffusion source 80 Ga 20 The composition of EDS point scanning position 80 Ga 20 2.9% of the total mass of the parent phase alloy and the diffusion source, and the results are as follows Figure 6 and Table 3.

[0118] Table 3 (Mn2Sb) in Example 3 0.89 Bi 0.11 Pr in the middle of the diffusion source 80 Ga 20 The composition of EDS point scanning position

[0119] Scan point Mn (at%) Ga (at%) Sb (at%) Pr (at%) Bi (at%) 1 64.63 0.01 34.17 0.01 1.17 2 51.25 0.47 43.63 0.09 4.56 3 49.54 1.02 14.40 3.29 31.75 4 21.12 0.00 0.08 0.36 56.51 5 8.88 0.00 34.63 0.45 54.7 6 8.84 0.00 33.33 0.40 51.07

[0120] From Figure 6 and Table 3, it can be known that above the melting point temperature of Pr 80 Ga 20 alloy, i.e. 580℃, no obvious grain boundary phase is formed, and the composition of Pr element accounts for a very small proportion in 6 positions, which can explain that above the melting point temperature, the process of forming double liquid phase diffusion is not mature, and compared with Example 1, different rare earth elements have different effects on the composition of alloy grain boundary phase.

[0121] The above are only preferred embodiments of the present application, and are not used to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for improving the physical properties of a Bi-rich phase of a Mn2Sb-based alloy material, characterized in that, The physical property is magnetic property, and the method comprises the following steps: mixing the parent phase alloy with a diffusion source, sintering at 500-850℃ for 15-36min to diffuse the diffusion source into the parent phase alloy; the diffusion source accounts for 2.9-30% of the total mass of the parent phase alloy and the diffusion source; The diffusion source is Dy 100-y Cu y , 5≤y≤40 or Pr 100-z Ga z , 5≤z≤40; The parent alloy is (Mn2Sb) 1-x Bi x 0 < x < 0.

2.

2. The method for improving the physical properties of a Bi-rich phase of a Mn2Sb-based alloy material according to claim 1, characterized in that, the sintering is followed by heat treatment; the heat treatment refers to annealing at the sintering temperature for 1-5 days and then cooling to 21-25℃.

3. The method for improving the physical properties of a Bi-rich phase of a Mn2Sb-based alloy material according to claim 1, characterized in that, the sintering pressure is 15-100Mpa.

4. The method for improving physical properties of a Bi-rich phase of a Mn2Sb-based alloy material according to claim 1, characterized in that, the particle size of the parent phase alloy is 10-50μm, and the particle size of the diffusion source is 1-50μm.

5. The method for improving the physical properties of a Bi-rich phase of a Mn2Sb-based alloy material according to claim 1, characterized in that, the specific preparation process of the parent phase alloy is as follows: According to a stoichiometric ratio, the parent phase alloy raw materials Mn, Sb and Bi are weighed respectively, and then each raw material is mixed and melted to obtain (Mn2Sb) 1-x Bi x Ingot casting, (Mn2Sb) 1-x Bi x Ingot annealing, crushing, to obtain the parent phase alloy; the specific preparation process of the diffusion source is as follows: According to the stoichiometric ratio, the diffusion source raw material Dy and Cu, or Pr and Ga are weighed respectively, mixed, melted to obtain Dy 100-y Cu y ingot or Pr 100-z Ga z ingot; Dy 100-y Cu y ingot or Pr 100-z Ga z ingot melted into a liquid and sprayed onto a rotating copper roll to obtain Dy 100-y Cu y rapidly quenched ribbon or Pr 100-z Ga z rapidly quenched ribbon, Dy 100-y Cu y rapidly quenched ribbon or Pr 100-z Ga z rapidly quenched ribbon pulverized to obtain the diffusion source.

6. The method for improving the physical properties of a Bi-rich phase containing Mn2Sb-based alloy material according to claim 5, characterized in that, the smelting temperature in the preparation process of the parent phase alloy is 950-1000℃, the annealing temperature is 680-700℃, and the annealing time is 5-7d; the smelting temperature in the preparation process of the diffusion source is 800-900℃.

7. The method for improving the physical properties of a Bi-rich phase of a Mn2Sb-based alloy material according to claim 5, characterized in that, the crushing is carried out by grinding or ball milling.

8. The method for improving the physical properties of a Bi-rich phase of a Mn2Sb-based alloy material according to claim 7, characterized in that, the grinding time is 30-60min.

9. The method for improving the physical properties of a Bi-rich phase of a Mn2Sb-based alloy material according to claim 7, characterized in that, the ball milling is carried out at a forward and reverse rotation speed of 200-500rpm for 40-60min, and the cycle is 5-10 times.

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