阅读说明：本技术 一种烧结钐钴永磁体的玻璃熔接方法 (Glass welding method for sintered samarium-cobalt permanent magnet ) 是由 方以坤 于晓杰 朱子斌 肖涛 刘海珍 凌棚生 韩伟 董生智 李卫 于 2020-12-23 设计创作，主要内容包括：本发明涉及一种烧结钐钴永磁体的玻璃熔接方法。选取两个未经表面电镀处理的烧结钐钴永磁体,加工成所需形状；分别对两个磁体的熔接面进行喷砂处理,依次用蒸馏水、丙酮清洗,干燥；将玻璃粉制成浆料涂覆在一个烧结钐钴永磁体的熔接面,涂敷层干燥后,将另一个一个烧结钐钴永磁体的熔接面放在涂敷层上；将两块磁体放于热处理炉中,加热至熔接温度并保温一定时间后,降温至室温,完成钐钴永磁体的熔接；所述熔接温度低于550℃。本发明提出的方法可以在550℃温度以下短时间快速完成烧结钐钴永磁体的熔接,且熔接体抗弯强度为80-90MPa。(The invention relates to a glass welding method of a sintered samarium cobalt permanent magnet. Selecting two sintered samarium-cobalt permanent magnets which are not subjected to surface electroplating treatment, and processing the two sintered samarium-cobalt permanent magnets into a required shape; carrying out sand blasting treatment on the welding surfaces of the two magnets respectively, and cleaning and drying the welding surfaces by using distilled water and acetone in sequence; preparing glass powder into slurry, coating the slurry on the welding surface of one sintered samarium-cobalt permanent magnet, and after the coating is dried, placing the welding surface of the other sintered samarium-cobalt permanent magnet on the coating; placing the two magnets in a heat treatment furnace, heating to a welding temperature, keeping the temperature for a certain time, and cooling to room temperature to complete welding of the samarium-cobalt permanent magnet; the fusion temperature is less than 550 ℃. The method provided by the invention can quickly complete the welding of the sintered samarium-cobalt permanent magnet at the temperature of below 550 ℃ in a short time, and the bending strength of the welding body is 80-90 MPa.)

1. A glass welding method of a sintered samarium cobalt permanent magnet is characterized by comprising the following steps:

(1) selecting two sintered samarium-cobalt permanent magnets which are not subjected to surface electroplating treatment, and processing the two sintered samarium-cobalt permanent magnets into a required shape; carrying out sand blasting treatment on the welding surfaces of the two magnets respectively, cleaning the welding surfaces with distilled water and acetone in sequence, and drying the welding surfaces;

(2) preparing glass powder into glass coating slurry, coating the glass coating slurry on the fusion joint surface of one sintered samarium-cobalt permanent magnet, and after drying the coating layer, placing the fusion joint surface of the other sintered samarium-cobalt permanent magnet on the coating layer; placing the two magnets in a heat treatment furnace, heating to the welding temperature, keeping the temperature for 5-20 minutes, and cooling to room temperature to complete the welding of the sintered samarium-cobalt permanent magnet; the fusion temperature is less than 550 ℃.

2. The method for glass fusion bonding of sintered samarium cobalt permanent magnets of claim 1 wherein in step (1) the pressure of the compressed air during the blasting is 0.5 to 1.0 MPa.

3. The method for glass fusion bonding of sintered samarium cobalt permanent magnets of claim 1 in which in step (1) the distance between the nozzle and the fusion bonded surface of the sintered samarium cobalt permanent magnet during the sand blasting is 80 to 150mm and the spray angle is 30 to 50 °.

4. The method for glass fusion bonding of sintered samarium cobalt permanent magnets of claim 1 wherein in step (1) the grit used in the grit blasting is selected from the group consisting of 0.5 to 1.0mm quartz grit, silicon carbide grit, and glass beads.

5. The method of glass fusion bonding of sintered samarium cobalt permanent magnets of claim 1 wherein in step (2) the chemical composition of the glass powder is expressed as, by weight percent: b is₂O₃ 6～10％、Bi₂O₃ 5～15％、ZnO 8～15％，SiO₂ 0.1～1％、Al₂O₃0.1-1% and the balance of PbO.

6. The method of glass fusion bonding of sintered samarium cobalt permanent magnets of claim 1 wherein in step (2) the chemical composition of the glass powder is expressed as, by weight percent: b is₂O₃ 7～10％、Bi₂O₃ 5～15％、ZnO 9～12.5％，SiO₂ 0.3～0.5％、Al₂O₃0.2-0.5% and the balance of PbO.

7. The method for glass fusion bonding of sintered samarium cobalt permanent magnets of claim 1 wherein in step (2) the heat treatment furnace is heated to 450-500 ℃ at 5-10 ℃/min and held for 5-20 minutes, and then cooled to room temperature at 2-7 ℃/min.

8. The method for glass fusion of a sintered samarium cobalt permanent magnet of claim 1 wherein in step (2) the method of making the glass coating paste is as follows:

I. preparing, weighing and mixing glass powder, placing the glass powder in a V-shaped mixer for uniform mixing, then placing the mixture in a corundum crucible, heating the mixture to 800 ℃ in an air atmosphere of a silicon-carbon rod electric furnace, preserving heat for 2 hours, pouring the mixture into deionized water for water quenching, drying the mixture, and crushing the mixture to be below 300 meshes by using a jet mill to obtain glass powder;

and II, mixing the glass powder and ethanol according to the weight ratio of 1: 0.8-1.5, and ball-milling and mixing in a ball mill for 1-2 hours to obtain glass coating slurry.

9. The method of glass fusion bonding of sintered samarium cobalt permanent magnets of claim 1 in which the flexural strength of the fused sintered samarium cobalt permanent magnets is 80 to 90 MPa.

10. The method of glass welding a sintered samarium cobalt permanent magnet of claim 1 wherein in step (2) the glass coating slip is brushed or sprayed onto the weld face of the sintered samarium cobalt permanent magnet with a coating thickness of 0.1 to 2 mm.

Technical Field

The invention belongs to the technical field of rare earth permanent magnet welding, and particularly relates to a glass welding method of a sintered samarium cobalt permanent magnet.

Background

The 2:17 type samarium cobalt sintered permanent magnet material has higher magnetic property, has the characteristics of high Curie temperature (830 ℃) and low temperature coefficient, and is a magnetic material which can not be replaced in the high temperature field. In practical application, the magnets need to be welded to meet the requirements of special structural design, and the difficult welding property of the sintered samarium-cobalt magnets makes the connection problem between the magnets become a bottleneck restricting the development of the samarium-cobalt magnets.

Currently, epoxy bonded samarium cobalt permanent magnets are commonly used, or mechanically attached magnets such as with bolts. Epoxy resin can age after long-term use, and samarium cobalt magnets are brittle materials, so that mechanical connection easily causes the breakage of the magnets and has great risk. In order to solve the problems, the Chinese patent application CN105081606A discloses a ribbon-shaped brazing material for rare earth cobalt-based permanent magnets and a preparation method thereof, and the Chinese patent application CN105081498A provides a welding method of sintered samarium cobalt magnets, wherein the welding temperature is higher than 800 ℃ when the brazing material and the sintered samarium cobalt magnets are tried to be welded in the material preparation process, but the technical scheme of carrying out glass welding on the samarium cobalt permanent magnets at lower temperature (lower than 550 ℃) in the prior art is not reported so far.

Disclosure of Invention

Aiming at the technical problems, the invention aims to provide a glass welding method of a sintered samarium cobalt permanent magnet, which can realize the welding of the sintered samarium cobalt permanent magnet at low temperature (lower than 550 ℃) in a short time.

In order to achieve the purpose, the invention provides the following technical scheme:

a glass welding method of a sintered samarium cobalt permanent magnet comprises the following steps:

(1) selecting two sintered samarium-cobalt permanent magnets which are not subjected to surface electroplating treatment, and processing the two sintered samarium-cobalt permanent magnets into a required shape; carrying out sand blasting treatment on the welding surfaces of the two magnets respectively, cleaning the welding surfaces with distilled water and acetone in sequence, and drying the welding surfaces;

(2) preparing glass powder into glass coating slurry, coating the glass coating slurry on the fusion joint surface of one sintered samarium-cobalt permanent magnet, and after drying the coating layer, placing the fusion joint surface of the other sintered samarium-cobalt permanent magnet on the coating layer; placing the two magnets in a heat treatment furnace, heating to the welding temperature, keeping the temperature for 5-20 minutes, and cooling to room temperature to complete the welding of the sintered samarium-cobalt permanent magnet; the fusion temperature is less than 550 ℃.

In the step (1), the pressure of the compressed air in the sand blasting treatment is 0.5-1.0 MPa.

In the step (1), the distance between the nozzle and the welding surface of the sintered samarium-cobalt permanent magnet in the sand blasting treatment is 80-150 mm, and the spraying angle is 30-50 degrees.

In the step (1), the sand used in the sand blasting treatment is selected from one of quartz sand, carborundum and glass beads with the thickness of 0.5-1.0 mm.

In the step (2), the chemical composition of the glass powder is represented by the following weight percentage: b is₂O₃ 6～10％、Bi₂O₃ 5～15％、ZnO 8～15％，SiO₂ 0.1～1％、Al₂O₃0.1-1% and the balance of PbO.

In the step (2), the chemical composition of the glass powder is represented by the following weight percentage: b is₂O₃ 7～10％、Bi₂O₃ 5～15％、ZnO 9～12.5％，SiO₂ 0.3～0.5％、Al₂O₃0.2-0.5% and the balance of PbO.

In the step (2), the heat treatment furnace is heated to 450-500 ℃ at a speed of 5-10 ℃/min, is kept for 5-20 minutes, and is cooled to room temperature at a speed of 2-7 ℃/min.

In the step (2), the method for preparing the glass coating paste comprises the following steps:

I. preparing, weighing and mixing glass powder, placing the glass powder in a V-shaped mixer for uniform mixing, then placing the mixture in a corundum crucible, heating the mixture to 800 ℃ in an air atmosphere of a silicon-carbon rod electric furnace, preserving heat for 2 hours, pouring the mixture into deionized water for water quenching, drying the mixture, and crushing the mixture to be below 300 meshes by using a jet mill to obtain glass powder;

and II, mixing the glass powder and ethanol according to the weight ratio of 1: 0.8-1.5, and ball-milling and mixing in a ball mill for 1-2 hours to obtain glass coating slurry.

The bending strength of the welded sintered samarium-cobalt permanent magnet is 80-90 MPa.

In the step (2), the glass coating slurry is brushed or sprayed on the welding surface of the sintered samarium-cobalt permanent magnet, and the thickness of the coating layer is 0.1-2 mm.

Compared with the prior art, the invention has the beneficial effects that:

the invention adopts a glass welding mode, designs a method for realizing glass welding sintering samarium cobalt permanent magnet at the temperature lower than 550 ℃, can realize the welding of the sintering samarium cobalt permanent magnet in a short time at low temperature, and provides a brand new technical scheme for the connection of the samarium cobalt magnet. The sintered samarium-cobalt permanent magnet glass welding method provided by the invention has the advantages of low welding temperature (450-500 ℃), short welding time (5-20 minutes) and high strength (the bending strength is 80-90 MPa).

Detailed Description

The present invention will be further illustrated with reference to the following examples.

The glass welding method of the sintered samarium cobalt permanent magnet comprises the following steps:

(1) selecting two sintered samarium-cobalt permanent magnets which are not subjected to surface electroplating treatment, and processing the sintered samarium-cobalt permanent magnets into required shapes by linear cutting; carrying out sand blasting treatment on the welding surfaces of the two magnets respectively, cleaning the welding surfaces with distilled water and acetone in sequence, and drying the welding surfaces;

(2) preparing glass powder into glass coating slurry, brushing or spraying the glass coating slurry on the welding surface of one sintered samarium-cobalt permanent magnet, and after drying, placing the welding surface of the other sintered samarium-cobalt permanent magnet on the dried glass powder; and (3) placing the two magnets in a heat treatment furnace, heating to 450-500 ℃ at the speed of 5-10 ℃/min, preserving heat for 5-20 minutes, and cooling to room temperature at the speed of 2-7 ℃/min to complete the welding of the samarium cobalt permanent magnet.

In the step (1), the sand blasting treatment comprises the following steps: the compressed air pressure is 0.5-1.0 MPa, the sand grains are selected from one of quartz sand, carborundum and glass beads with the thickness of 0.5-1.0 mm, the distance between a nozzle and the welding surface of the sintered samarium-cobalt permanent magnet is 80-150 mm, and the spraying angle is 30-50 degrees.

In the step (2), the chemical composition of the glass powder comprises the following components in percentage by weight: 65-80% of PbO, B₂O₃ 6～10％、Bi₂O₃ 5～15％、ZnO 8～15％，SiO₂ 0.1～1％、Al₂O₃0.1 to 1 percent. The glass powder raw materials which are uniformly mixed according to the chemical composition are placed in a refractory crucible, heated and melted in the air atmosphere, and poured into deionized water for water quenching after heat preservation for a certain time, and then are crushed into glass powder after drying.

In the step (2), the preparation method of the glass coating slurry comprises the following steps: mixing the glass powder with ethanol, acetone, isopropanol and the like according to a weight ratio of 1:1, and carrying out ball milling and mixing in a ball mill for 1-2 h to obtain glass coating slurry.

Example 1

(1) Selecting two sintered samarium-cobalt permanent magnets which are not subjected to surface electroplating treatment, processing the sintered samarium-cobalt permanent magnets into blocks of 10 multiplied by 5mm by linear cutting, performing sand blasting treatment on a welding surface, wherein the pressure of compressed air is 0.5MPa, the used sand grains are 1mm quartz sand, the distance between a nozzle and the surface of the samarium-cobalt is 80mm, the spraying angle is 30 degrees, and cleaning and drying the samarium-cobalt permanent magnets by using distilled water and acetone respectively;

(2) selecting glass powder as the following components in percentage by weight: PbO 75%, B₂O₃10% of Bi₂O₃5% of ZnO, 9% of SiO₂0.5% of Al₂O₃Is 0.5%. The raw materials are weighed and mixed according to the proportion and then are placed in a V-shaped mixer to be mixed evenly. Placing the uniformly mixed raw materials into a corundum crucible, heating to 800 ℃ in an air atmosphere of a silicon carbide rod electric furnace, preserving heat for 2 hours, pouring into deionized water for water quenching, drying, and crushing to below 300 meshes by using a jet mill. The glass frit manufacturing process is well known to those of ordinary skill in the glass industry.

Mixing the glass powder and ethanol according to the weight ratio of 1:1, and carrying out ball milling and mixing in a ball mill for 1h to obtain glass coating slurry.

And (3) brushing the glass coating slurry on the welding surface of one sintered samarium-cobalt permanent magnet by using a brush, drying for 1 hour in an electric heating forced air drying oven, putting the welding surface of the other sintered samarium-cobalt permanent magnet on the dried glass powder, heating to 450 ℃ in a heat treatment furnace at 6 ℃/min, keeping the temperature for 10 minutes, cooling to room temperature at 5 ℃/min, and taking out to complete the welding of the samarium-cobalt permanent magnet.

Example 2

(1) Selecting two sintered samarium-cobalt permanent magnets which are not subjected to surface electroplating treatment, processing the sintered samarium-cobalt permanent magnets into blocks of 10 multiplied by 5mm by linear cutting, performing sand blasting treatment on a welding surface, wherein the pressure of compressed air is 0.6MPa, the used sand grains are 1mm of carborundum, the distance between a nozzle and the surface of the samarium-cobalt is 100mm, the spraying angle is 40 degrees, and cleaning and drying are respectively performed by using distilled water and acetone;

(2) selecting glass powder as the following components in percentage by weight: PbO 70% and B₂O₃8% of Bi₂O₃10% of ZnO, 11.5% of SiO₂0.3% of Al₂O₃Is 0.2%. The raw materials are weighed and mixed according to the proportion and then are placed in a V-shaped mixer to be mixed evenly. And (3) putting the uniformly mixed raw materials into a corundum crucible, heating to 850 ℃ in an air atmosphere of a silicon-carbon rod electric furnace, preserving heat for 2.5 hours, pouring into deionized water for water quenching, drying, and ball-milling to below 300 meshes by using a ball mill. The glass frit manufacturing process is well known to those of ordinary skill in the glass industry.

Mixing the glass powder and acetone according to the weight ratio of 1:1, and ball-milling and mixing in a ball mill for 1.5h to prepare glass coating slurry.

And (3) brushing the glass coating slurry on the welding surface of one sintered samarium-cobalt permanent magnet by using a brush, drying for 1 hour in an electric heating forced air drying oven, putting the welding surface of the other sintered samarium-cobalt permanent magnet on the dried glass powder, heating to 480 ℃ in a heat treatment furnace at the speed of 7 ℃/min, keeping the temperature for 15 minutes, cooling to room temperature at the speed of 6 ℃/min, and taking out to complete the welding of the samarium-cobalt permanent magnet.

Example 3

(1) Selecting two sintered samarium-cobalt permanent magnets which are not subjected to surface electroplating treatment, processing the sintered samarium-cobalt permanent magnets into blocks of 10 multiplied by 5mm by linear cutting, performing sand blasting treatment on a welding surface, wherein the pressure of compressed air is 0.8MPa, the used sand grains are 0.5mm glass beads, the distance between a nozzle and the surface of the samarium-cobalt is 110mm, the spraying angle is 50 degrees, and cleaning and drying the samarium-cobalt permanent magnets respectively by using distilled water and acetone;

(2) selecting glass powder as the following components in percentage by weight: 65% of PbO and B₂O₃7% of Bi₂O₃15% of ZnO, 12.5% of SiO₂0.3% of Al₂O₃Is 0.2%. The raw materials are weighed and mixed according to the proportion and then are placed in a V-shaped mixer to be mixed evenly. And (3) putting the uniformly mixed raw materials into a corundum crucible, heating to 780 ℃ in an air atmosphere of a silicon carbide rod electric furnace, preserving heat, pouring into deionized water for water quenching after 2.5 hours, drying, and ball-milling to below 300 meshes by using a ball mill. The glass frit manufacturing process is well known to those of ordinary skill in the glass industry.

Mixing glass powder and isopropanol according to the weight ratio of 1:1, and ball-milling and mixing for 2h in a ball mill to obtain glass coating slurry.

And (3) brushing the glass coating slurry on the welding surface of one sintered samarium-cobalt permanent magnet by using a brush, drying for 1 hour in an electric heating forced air drying oven, putting the welding surface of the other sintered samarium-cobalt permanent magnet on the dried glass powder, heating to 500 ℃ in a heat treatment furnace at the speed of 5 ℃/min, keeping the temperature for 8 minutes, cooling to room temperature at the speed of 8 ℃/min, and taking out to complete the welding of the samarium-cobalt permanent magnet. The implementation effect is as follows:

as can be seen from comparison of examples 1-3 and comparative examples in Table 1, by adopting the glass welding method of the sintered samarium-cobalt permanent magnet provided by the invention, the bending strength of the welded magnet is higher than that of an epoxy resin bonded magnet, and the bending strength of the samarium-cobalt magnet matrix is achieved. The samarium cobalt permanent magnet welding method has the advantages that the samarium cobalt permanent magnet is quickly welded below 550 ℃, and the welding body has good mechanical properties.

TABLE 1

Comparison of bending strength of glass-welded sintered samarium-cobalt magnet and epoxy-bonded sintered samarium-cobalt magnet