CN101476055A

CN101476055A - Preparation of fully dense massive anisotropic nanocrystalline SmCo5 magnet

Info

Publication number: CN101476055A
Application number: CNA2009100770091A
Authority: CN
Inventors: 岳明; 刘卫强; 张东涛; 张久兴; 吕文春
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2009-01-16
Filing date: 2009-01-16
Publication date: 2009-07-08
Anticipated expiration: 2029-01-16
Also published as: CN101476055B

Abstract

The invention pertaining to the field of preparing magnetic materials provides a method of preparing full-compact block body eolotropy nanocrystalline SmCo5 magnet for solving the problems that by the conventional sinter method of preparing SmCo5 permanent magnet alloy, the technique is complex, the mechanical performances and corrosion resistance capability of the produced alloy is not good, and the like.The method comprises steps of preparing key metal for smelting by using Sm and Co according to the mixture ratio of the components of SmCo5, performing the ball mill process to obtain amorphous alloy powder, performing quick hot pressing and heat distortion processes to the amorphous alloy powder sequentially, finally obtaining the ull-compact block body eolotropy nanocrystalline SmCo5 permanent magnet alloy. The method has advantages of simple technique, short production cycle and low cost, and the produced magnet has high degree of compactness, fine grains, a SmCo5 phase C axes crystal texture and high magnetic property.

Description

Fully compact massive anisotropic nanocrystalline SmCo 5The preparation method of magnet

Technical field

The invention belongs to the magneticsubstance preparation field, be specifically related to the nanocrystalline SmCo of a kind of full compact block anisotropy ₅The preparation method of magnet.

Background technology

SmCo ₅Permanent magnet alloy is the first-generation RE permanent magnetic alloy of developing the sixties in last century, not only has excellent intrinsic magnetic properties, and has the good high-temperature characteristic, and promptly alloy still can keep higher magnetic property under hot environment.Therefore, this class permanent magnet material still has good practical values so far, to being used widely under the higher environment of temperature requirement.

At present, generally adopt traditional powder metallurgy process to prepare SmCo at industrial quilt ₅Permanent magnet alloy comprises following process substantially: alloy melting → broken powder process → magnetic field orientating compacting → sintering → thermal treatment → machine-shaping.Adopt the SmCo of this method preparation ₅Permanent magnet alloy has higher magnetic property, but has following deficiency: at first, the grain-size of prepared alloy is a micro-meter scale, so the mechanical property of alloy is relative with erosion resistance relatively poor, has limited the range of application of alloy to a certain extent; Secondly, problem such as there is complex procedures in prior powder metallurgy technology, the production cycle is long and homogeneity of product is relatively poor, thereby make the manufacturing cost of alloy high.Therefore, explore preparation high-performance SmCo ₅The novel method of permanent magnet alloy is significant.

In order to make SmCo ₅Permanent magnet alloy obtains high magnetic property, must adopt effective means to make alloy obtain magneticanisotropy.In above-mentioned prior powder metallurgy method, SmCo ₅Permanent magnet alloy is to utilize the magnetic field orientating method of magnetocrystalline anisotropy to obtain magneticanisotropy.In fact, also be a kind of effective way that obtains magneticanisotropy with the alloy plastic deformation, and in another kind of RE permanent magnetic alloy Nd-Fe-B, obtained success.But also do not obtain fine and close magneticanisotropy SmCo at present by the alloy plastic deformation ₅The precedent of magnet.

Summary of the invention

The objective of the invention is to solve the problems of the prior art, and provide a kind of full compact block anisotropy nanocrystalline SmCo ₅The preparation method of magnet.

The present invention by with behind Sm and the Co master alloy melting, ball milling, fast hot pressing and thermal distortion are handled, and make fully compact massive SmCo ₅Nanocrystalline permanent magnet alloy specifically may further comprise the steps:

1) with purity greater than 99.9% Sm and purity greater than 99.9% Co metal according to SmCo ₅Composition proportion be under 99.999% the argon shield condition in purity, in shower furnace behind the master alloy melting, be ball milling 5 hours under 99.999% the argon shield condition with mother alloy in purity, obtain the amorphous alloy powder (see figure 1);

2) after amorphous alloy powder being packed in the carboloy mould, carry out quick hot-pressing processing and obtain the nanocrystalline SmCo of complete fine and close isotropy ₅Magnet, hot pressing parameters is fast: under the pressure of 100-1000Mpa,, be warming up to 600-700 ℃ from room temperature with the temperature rise rate of 50-200 ℃/min, and insulation 0-10min;

3) to complete fine and close isotropy SmCo ₅Magnet carries out the Rapid Thermal compressive strain to be handled, and obtains the nanocrystalline SmCo of complete fine and close anisotropy ₅Magnet, Rapid Thermal compressive strain processing parameter is: under the pressure of 20-60Mpa, be warming up to 750-900 ℃ with the temperature rise rate of 50-150 ℃/min, and insulation 0-10min.

The present invention has following beneficial effect:

1) the prepared SmCo of the present invention ₅Magnet has tangible SmCo ₅Phase C axialite body texture (see figure 2) and corresponding remarkable magneticanisotropy (Fig. 5); Magnet density reaches more than 98% of congruent materials theory density (seeing Table 1); The average grain size of magnet is nano level (seeing Fig. 3 and Fig. 4); Has good magnetic performance (seeing Table 1).

2) preparation technology of the present invention is simple, and is with short production cycle, and cost is low.

Description of drawings

The XRD figure spectrum (2 θ are angle of diffraction) of the non-crystalline state powder that Fig. 1, the present invention are prepared.

The fully compact massive anisotropic nanocrystalline SmCo of Fig. 2, embodiment 1 preparation ₅The crystalline structure XRD figure spectrum that is parallel to deformation direction of magnet.

The fully compact massive anisotropic nanocrystalline SmCo of Fig. 3, embodiment 1 preparation ₅The crystal grain micro-organization chart that is parallel to deformation direction (transmission electron microscope photo) of magnet.

The fully compact massive anisotropic nanocrystalline SmCo of Fig. 4, embodiment 1 preparation ₅The crystal grain micro-organization chart perpendicular to deformation direction of magnet (transmission electron microscope photo).

The fully compact massive anisotropic nanocrystalline SmCo of Fig. 5, embodiment 1 preparation ₅The magnetzation curve that is parallel and perpendicular to deformation direction of magnet and magnetic hysteresis loop (H is a magneticstrength, and M is the specific magnetising moment).

The invention will be further described below in conjunction with the drawings and specific embodiments.

Embodiment

Embodiment 1

1) with purity greater than 99.9% Sm and purity greater than 99.9% Co metal according to SmCo ₅Composition proportion adopt the melting of vacuum shower furnace after, carried out fragmentation and ball milling 5 hours, the acquisition amorphous alloy powder;

2) amorphous alloy powder is packed into carry out quick hot pressing in the carboloy grinding tool: under the pressure of 100Mpa,, be warming up to 700 ℃ from room temperature with the temperature rise rate of 50 ℃/min, and insulation 0min, obtain the nanocrystalline SmCo of complete fine and close isotropy ₅Magnet;

3) with the nanocrystalline SmCo of complete fine and close isotropy ₅Magnet carries out the Rapid Thermal compressive strain to be handled: under the pressure of 20Mpa, be warming up to 900 ℃ with the temperature rise rate of 50 ℃/min, and insulation 0min, deformation ratio 90% obtains the nanocrystalline SmCo of complete fine and close anisotropy ₅Magnet (magnetic property and density see Table).

Embodiment 2

2) amorphous alloy powder is packed into carry out quick hot pressing in the carboloy grinding tool: under the pressure of 1000Mpa,, be warming up to 600 ℃ from room temperature with the temperature rise rate of 200 ℃/min, and insulation 10min, obtain the nanocrystalline SmCo of complete fine and close isotropy ₅Magnet;

3) with the nanocrystalline SmCo of complete fine and close isotropy ₅Magnet carries out the Rapid Thermal compressive strain to be handled: under the pressure of 60Mpa, be warming up to 750 ℃ with the temperature rise rate of 150 ℃/min, and insulation 10min, deformation ratio 70% obtains the nanocrystalline SmCo of complete fine and close anisotropy ₅Magnet (magnetic property and density see Table).

Embodiment 3

2) amorphous alloy powder is packed into carry out quick hot pressing in the carboloy grinding tool: under the pressure of 500Mpa,, be warming up to 650 ℃ from room temperature with the temperature rise rate of 100 ℃/min, and insulation 5min, obtain the nanocrystalline SmCo of complete fine and close isotropy ₅Magnet;

3) with the nanocrystalline SmCo of complete fine and close isotropy ₅Magnet carries out the Rapid Thermal compressive strain to be handled: under the pressure of 30Mpa, be warming up to 850 ℃ with the temperature rise rate of 100 ℃/min, and insulation 5min, deformation ratio 80% obtains the nanocrystalline SmCo of complete fine and close anisotropy ₅Magnet (magnetic property and density see Table).

The fully compact massive anisotropic nanocrystalline SmCo for preparing among table 1, the embodiment 1-3 ₅The magnetic property of magnet and density

Claims

1, a kind of fully compact massive anisotropic nanocrystalline SmCo ₅The preparation method of magnet is characterized in that, may further comprise the steps:

1) with purity greater than 99.9% Sm and purity greater than 99.9% Co metal according to SmCo ₅Composition proportion be under 99.999% the argon shield condition in purity, in shower furnace behind the master alloy melting, be ball milling 5 hours under 99.999% the argon shield condition with mother alloy in purity, obtain amorphous alloy powder;