阅读说明：本技术 一种具有良好润湿性能的钐钴磁体玻璃涂层及其制备方法 (Samarium-cobalt magnet glass coating with good wettability and preparation method thereof ) 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：本发明涉及一种具有良好润湿性能的钐钴磁体玻璃涂层及其制备方法。该玻璃涂层的化学组成按重量百分比为：Al-2O-32～6％、B-2O-310～18％、Na-2O 15～25％、BaO 2～8％、CaO 5～10％、MgO 0～5％、MnO 1～6％、FeO 0.5～3％、NiO 0.5～3％、CuO 0.1～2％、CoO 0.1～2％,其余为SiO-2；经原料混合、熔化制粉、制备浆料后涂覆在钐钴磁体表面,干燥后经真空或惰性气氛热处理完成制备；在热处理过程中阻止镍、铜和钴的单质析出。本发明的玻璃涂层具有在非氧化气氛下与钐钴良好润湿性的优点。(The invention relates to a samarium cobalt magnet glass coating with good wettability and a preparation method thereof. The glass coating comprises the following chemical components in percentage by weight: al (Al) 2 O 3 2～6％、B 2 O 3 10～18％、Na 2 15-25% of O, 2-8% of BaO, 5-10% of CaO, 0-5% of MgO, 1-6% of MnO, 0.5-3% of FeO, 0.5-3% of NiO, 0.1-2% of CuO, 0.1-2% of CoO and the balance of SiO 2 (ii) a The samarium cobalt magnet is coated on the surface of the samarium cobalt magnet after raw material mixing, powder preparation by melting and slurry preparation, and the preparation is completed by vacuum or inert atmosphere heat treatment after drying; the simple substances of nickel, copper and cobalt are prevented from being separated out in the heat treatment process. The glass coating of the invention has the advantage of good wettability with samarium cobalt in a non-oxidizing atmosphere.)

1. A samarium cobalt magnet glass coating with good wettability is characterized in that the chemical composition of the glass coating is as follows by weight percent: al (Al)₂O₃ 2～6％、B₂O₃ 10～18％、Na₂15-25% of O, 2-8% of BaO, 5-10% of CaO, 0-5% of MgO, 1-6% of MnO, 0.5-3% of FeO, 0.5-3% of NiO, 0.1-2% of CuO, 0.1-2% of CoO and the balance of SiO₂。

2. A samarium cobalt magnet glass coating according to claim 1, characterised in that the MnO is 1 to 4%, NiO is 0.5 to 1%, CuO is 0.1 to 0.5%, CoO is 0.1 to 0.5%.

3. A samarium cobalt magnet glass coating as defined in claim 1, wherein the SiO is₂45～53％、Al₂O₃ 2～6％、B₂O₃ 10～13％、Na₂O 15～22.5％、BaO 2～3％、CaO 5～6％、MgO 0.5～2％、MnO 1～5％、FeO 1～3％、NiO 0.5～3％、CuO 0.2～2％、CoO 0.3～2％。

4. The samarium cobalt magnet glass coating of claim 1, wherein the glass coating is coated on the surface of the samarium cobalt magnet after mixing of the raw materials, milling by melting, preparation of a slurry, drying, and heat treating in a vacuum or inert atmosphere to complete the preparation.

5. A samarium cobalt magnet glass coating as defined in claim 1, wherein the glass coating has a wetting angle with the samarium cobalt magnet of less than 90 ° and is capable of spreading completely across the surface of the magnet.

6. A method of making a samarium cobalt magnet glass coating as defined in claim 1, comprising the steps of:

(1) proportioning and mixing according to the component ratio

Adopts analytically pure raw materials, and comprises the following chemical compositions in percentage by weight: al (Al)₂O₃2～6％、B₂O₃ 10～18％、Na₂15-25% of O, 2-8% of BaO, 5-10% of CaO, 0-5% of MgO, 1-6% of MnO, 0.5-3% of NiO, 0.5-3% of FeO, 0-2% of CuO, 0-2% of CoO and the balance of SiO₂After the components are proportioned, the mixture is placed in a V-shaped mixer to be uniformly mixed;

(2) melting and powdering

Putting the uniformly mixed raw materials into a refractory crucible, heating and melting the raw materials in an air atmosphere, keeping the temperature for a certain time, pouring the raw materials into deionized water for water quenching, drying and crushing the raw materials into glass powder;

(3) preparing the slurry

Uniformly mixing glass powder and a suspension medium in a ball mill according to the weight ratio of 1: 0.8-1.2 to prepare glass coating slurry;

(4) preparing the coating

The glass coating paste is coated on the surface of a samarium-cobalt magnet, dried, subjected to heat treatment in vacuum or inert gas atmosphere, and then naturally cooled to room temperature.

7. The method according to claim 6, wherein in the step 1, SiO is used₂The raw material source of the quartz sand is quartz sand; al (Al)₂O₃The raw material source of the compound is aluminum hydroxide; b is₂O₃The raw material source of the compound is boric acid or borax; the raw material source of CaO is calcium carbonate; the raw material source of BaO is carbonic acidBarium; na (Na)₂The raw material source of O is sodium carbonate; the MnO raw material source is one or more of manganese carbonate, manganese monoxide, manganese dioxide, manganous oxide and manganous manganic oxide; the source of the NiO is one or more of nickel protoxide and nickel oxide; the raw material source of FeO is one or more of ferric oxide, ferric oxalate and ferroferric oxide; the raw material source of CuO is one or more of cupric oxide, cuprous oxide and cupric carbonate; the raw material source of CoO is one or more of cobalt monoxide, cobalt dioxide, cobaltosic oxide and cobalt carbonate.

8. The method according to claim 6, wherein in the step 2, the refractory crucible is a corundum, quartz, zirconia or platinum crucible.

9. The method according to claim 6, wherein the heating temperature in step 2 is 1300 ℃ to 1400 ℃ and the holding time is 2 ± 0.5 hours.

10. The production method according to claim 6, wherein in the step 3, the particle size of the glass frit is 300 mesh or less.

11. The preparation method according to claim 6, wherein in the step 3, the suspension medium is one or more of ethanol, acetone, isopropanol and acetylacetone.

12. The preparation method according to claim 6, wherein in the step 4, the heat treatment temperature is 800 ℃ to 850 ℃ and the holding time is 3 to 20 minutes.

Technical Field

The invention belongs to the technical field of magnet surface protection, relates to a glass coating for coating on a samarium cobalt permanent magnet surface to play a protection role, and particularly relates to a samarium cobalt magnet glass coating with good wettability and a preparation method thereof.

Background

The 2:17 type samarium cobalt sintered permanent magnet material has the characteristics of higher magnetic property, high Curie temperature (850 ℃) and low temperature coefficient, so the material is an irreplaceable magnetic material in the high-temperature field. However, since Sm is very active and is easily reacted with oxygen in the air, 2:17 type samarium cobalt sintered permanent magnet materials are oxidized when used at high temperature for a long time, resulting in a decrease in magnetic properties.

The preparation of the protective coating on the surface of the samarium cobalt permanent magnet is an effective technical means for improving the oxidation resistance of the samarium cobalt permanent magnet. In addition to electroplating Ni, Cu, Zn, for example, chinese patent application "a method for surface protection of samarium cobalt magnet workpiece" (application No. 201410521148.X) proposes to deposit a protective film after depositing a Ni-based thin film on the surface of samarium cobalt magnet by using a physical vapor deposition technique such as magnetron sputtering, evaporation plating, sputtering plating, etc. There are also patent documents that propose the preparation of ceramic coatings on the surface of samarium cobalt magnets, for example, the Chinese patent applications "A method for preparing samarium cobalt permanent magnet with ceramic layer" (application No. 201710989114.7) and "A method for preparing surface-treated samarium cobalt permanent magnet" (application No. 201810625209.5) propose NiFe₂O₄Coating; chinese patent application' a high-resistanceSamarium cobalt permanent magnets and methods of making them "(application No. 201510845427.6) propose silicon nitride ceramic protective coatings, but no method of making the coatings is disclosed; chinese patent application 'preparation method of samarium-cobalt permanent magnet with ceramic layer' (application number: 201810704773.6) proposes that Al is prepared on the surface of samarium-cobalt magnet by adopting plasma spraying technology₂O₃-NiO composite ceramic coating.

The glass coating has wide raw material sources and simple preparation process, and is used for high-temperature oxidation resistance of metal materials such as titanium alloy, high-temperature alloy, stainless steel and the like. Although there are patent documents reporting that a glass coating is used for surface protection of neodymium iron boron magnet, such as chinese patent application "a method for preparing enamel coating on surface of sintered neodymium iron boron magnet" (application No. 201810074697.5) "a method for preparing glass coating on surface of neodymium iron boron magnet" (application No. 201910671224.8), however, the above-mentioned composition of glass coating on surface of neodymium iron boron magnet cannot be applied to samarium cobalt magnet, wherein "a method for preparing enamel coating on surface of sintered neodymium iron boron magnet" (application No. 201810074697.5) provides an enamel coating composition in which a large amount of oxidant is added, which can oxidize samarium element in samarium cobalt magnet, and reduce magnetic performance; "A method for preparing neodymium-iron-boron magnet surface glass coating" (application number: 201910671224.8), the proposed glass coating composition contains Al₂O₃The content is as high as 10 percent, which causes high glass melting temperature and can be melted rapidly in the laser cladding process, but the conventional heat treatment process is not suitable. Currently, glass coatings for samarium cobalt magnets have not been reported. Since the glass coating enameling process on the surface of a samarium cobalt magnet needs to be performed in a vacuum or an inert atmosphere, and the wettability of glass with samarium cobalt in a non-oxidizing atmosphere is poor, there is a need to improve the wettability of the glass coating on the surface of a samarium cobalt magnet.

Disclosure of Invention

In view of the foregoing, it is an object of the present invention to provide a samarium cobalt magnet glass coating having good wetting properties.

It is another object of the present invention to provide a method for making a samarium cobalt magnet glass coating having good wetting properties, as described above.

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

a samarium cobalt magnet glass coating with good wettability comprises the following chemical components in percentage by weight: al (Al)₂O₃ 2～6％、B₂O₃ 10～18％、Na₂15-25% of O, 2-8% of BaO, 5-10% of CaO, 0-5% of MgO, 1-6% of MnO, 0.5-3% of FeO, 0.5-3% of NiO, 0.1-2% of CuO, 0.1-2% of CoO and the balance of SiO₂。

Preferably, MnO is 1-4%, NiO is 0.5-1%, CuO is 0.1-0.5%, and CoO is 0.1-0.5%.

Preferably, SiO₂ 45～53％、Al₂O₃ 2～6％、B₂O₃ 10～13％、Na₂O 15～22.5％、BaO 2～3％、CaO 5～6％、MgO 0.5～2％、MnO 1～5％、FeO 1～3％、NiO 0.5～3％、CuO 0.2～2％、CoO 0.3～2％。

The glass coating is coated on the surface of the samarium cobalt magnet after raw material mixing, powder preparation by melting and slurry preparation, and the preparation is completed by vacuum or inert atmosphere heat treatment after drying.

The wetting angle of the glass coating to the samarium cobalt magnet is less than 90 degrees and can be completely spread on the surface of the magnet.

A preparation method of a samarium cobalt magnet glass coating comprises the following steps:

(1) proportioning and mixing according to the component ratio

Adopts analytically pure raw materials, and comprises the following chemical compositions in percentage by weight: al (Al)₂O₃ 2～6％、B₂O₃ 10～18％、Na₂15-25% of O, 2-8% of BaO, 5-10% of CaO, 0-5% of MgO, 1-6% of MnO, 0.5-3% of NiO, 0.5-3% of FeO, 0-2% of CuO, 0-2% of CoO and the balance of SiO₂After the components are proportioned, the mixture is placed in a V-shaped mixer to be uniformly mixed;

(2) melting and powdering

Putting the uniformly mixed raw materials into a refractory crucible, heating and melting the raw materials in an air atmosphere, keeping the temperature for a certain time, pouring the raw materials into deionized water for water quenching, drying and crushing the raw materials into glass powder;

(3) preparing the slurry

Uniformly mixing glass powder and a suspension medium in a ball mill according to the weight ratio of 1: 0.8-1.2 to prepare glass coating slurry;

(4) preparing the coating

The glass coating paste is coated on the surface of a samarium-cobalt magnet, dried, subjected to heat treatment in vacuum or inert gas atmosphere, and then naturally cooled to room temperature.

In the step 1, SiO₂The raw material source of the quartz sand is quartz sand; al (Al)₂O₃The raw material source of the compound is aluminum hydroxide; b is₂O₃The raw material source of the compound is boric acid or borax; the raw material source of CaO is calcium carbonate; the raw material source of BaO is barium carbonate; na (Na)₂The raw material source of O is sodium carbonate; the MnO raw material source is one or more of manganese carbonate, manganese monoxide, manganese dioxide, manganous oxide and manganous manganic oxide; the source of the NiO is one or more of nickel protoxide and nickel oxide; the raw material source of FeO is one or more of ferric oxide, ferric oxalate and ferroferric oxide; the raw material source of CuO is one or more of cupric oxide, cuprous oxide and cupric carbonate; the raw material source of CoO is one or more of cobalt monoxide, cobalt dioxide, cobaltosic oxide and cobalt carbonate.

In the step 2, the refractory crucible is a corundum, quartz, zirconia or platinum crucible.

In the step 2, the heating temperature is 1300-1400 ℃, and the heat preservation time is 2 +/-0.5 hours.

In the step 3, the granularity of the glass powder is less than 300 meshes.

In the step 3, the suspension medium is one or more of ethanol, acetone, isopropanol and acetylacetone.

In the step 4, the heat treatment temperature is 800-850 ℃, and the heat preservation time is 3-20 minutes.

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

the glass coating prepared by the invention has good wettability (the wetting angle is less than 90 degrees) with a samarium cobalt magnet after vacuum or inert atmosphere heat treatment, and can be completely spread on the surface of the magnet. The invention improves the wettability of the glass coating on the permanent magnet surface of samarium cobalt by controlling the proportion of oxides (MnO, FeO, NiO, CuO, CoO and the like) which can reduce the surface tension of the glass melt in the glass composition.

Detailed Description

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

The invention provides a samarium cobalt magnet glass coating with good wettability, which comprises the following chemical components in percentage by weight: SiO 2₂ 45～55％、Al₂O₃ 2～6％、B₂O₃ 10～18％、Na₂O 15～25％、BaO 2～8％、CaO 5～10％、MgO 0～5％、MnO 1～6％、FeO 0.5～3％、NiO 0.5～3％、CuO 0.1～2％、CoO 0.1～2％。

Wherein, when the MnO weight percentage is 4-6%, the weight percentages of NiO, CuO and CoO are not limited in the above range.

When the MnO weight percentage is less than 4%, the NiO weight percentage is not more than 1%, the CuO weight percentage is not more than 0.5%, and the CoO weight percentage is not more than 0.5%.

The inventors of the present invention have discovered that when a glass coating is applied to the surface of a samarium cobalt magnet, the elements of nickel, copper, and cobalt can precipitate out after heat treatment in a vacuum or inert atmosphere, resulting in a glass coating that is non-wetting on the surface of the samarium cobalt magnet. The invention can prevent the metal simple substance from being separated out and improve the wettability of the glass on the surface of the samarium cobalt magnet by improving the content of MnO of the glass and simultaneously limiting the content of oxides such as NiO, CuO, CoO and the like.

The invention provides a preparation method of a samarium cobalt magnet glass coating with good wettability, which comprises the following steps:

1. proportioning and mixing according to component ratio

Adopting analytically pure raw materials, mixing the raw materials according to the required component proportion, and uniformly mixing the raw materials in a V-shaped mixer;

2. melting and powdering

And (3) putting the uniformly mixed raw materials into a refractory crucible, heating to 1300-1400 ℃ in an air atmosphere, preserving heat for 2 hours, pouring into deionized water for water quenching, drying, and crushing to below 300 meshes by using a ball mill or a jet mill.

3. Preparation of the slurry

Mixing the glass powder and the suspension medium in a ball mill for 1-2 hours according to the weight percentage of 1:1 to prepare the glass coating slurry.

4. Preparation of the coating

The glass coating slurry is coated on the surface of the samarium cobalt magnet by methods of brushing, spraying and the like, dried for 1-5 hours, heated to 800-850 ℃ in vacuum or inert gas atmosphere, kept warm for 3-20 minutes, and naturally cooled to room temperature.

Example 1

1. Proportioning and mixing according to the proportion of the components

The raw materials for introducing each oxide were weighed out in accordance with the oxide composition of example 1 in table 1. Wherein, SiO₂Introduced in the form of quartz sand, Al₂O₃Introduced in the form of aluminium hydroxide, B₂O₃Introducing boric acid or borax, MgO in magnesium carbonate, CaO in calcium carbonate, BaO in barium carbonate, Na₂O is introduced in the form of sodium carbonate or borax, MnO is introduced in the form of manganese dioxide, NiO is introduced in the form of nickel sesquioxide, FeO is introduced in the form of ferric oxide, CuO is introduced in the form of copper oxide, and CoO is introduced in the form of cobaltous oxide. This conversion process is well known to those skilled in the art. Weighing and mixing the raw materials according to the proportion, and placing the mixture in a V-shaped mixer for uniform mixing.

2. Melting and powdering

Placing the uniformly mixed raw materials into a corundum crucible, heating to 1400 ℃ 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.

3. Preparation of the slurry

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.

4. Preparation of glass coatings

The glass coating paste is brushed on the surface of a samarium cobalt magnet by a brush, dried for 1 hour in an electric heating forced air drying oven, heated to 850 ℃ in vacuum or inert gas atmosphere, kept warm for 3 minutes, and then naturally cooled to room temperature.

The implementation effect is as follows: good spreading of the glass coating on the magnet surface was observed, indicating good wetting properties.

Example 2

1. Proportioning and mixing according to the proportion of the components

The raw materials for introducing each oxide were weighed in accordance with the oxide composition of example 2 in table 1. Wherein, SiO₂Introduced in the form of quartz sand, Al₂O₃Introduced in the form of aluminium hydroxide, B₂O₃Introducing boric acid or borax, MgO in magnesium carbonate, CaO in calcium carbonate, BaO in barium carbonate, Na₂O is introduced in the form of sodium carbonate or borax, MnO is introduced in the form of manganese monoxide, NiO is introduced in the form of nickel protoxide, FeO is introduced in the form of ferroferric oxide, CuO is introduced in the form of cuprous oxide, and CoO is introduced in the form of cobaltosic oxide. This conversion process is well known to those skilled in the art. Weighing and mixing the raw materials according to the proportion, and placing the mixture in a V-shaped mixer for uniform mixing.

2. Melting and powdering

Putting the uniformly mixed raw materials into a quartz crucible, heating the raw materials to 1380 ℃ in an air atmosphere of a silicon-carbon rod electric furnace, preserving the heat for 2.5 hours, pouring the raw materials into deionized water for water quenching, drying the mixture, and ball-milling the mixture to below 300 meshes by using a ball mill.

3. Preparation of the slurry

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.

4. Preparation of glass coatings

The glass coating paste is brushed on the surface of a samarium cobalt magnet by a brush, dried for 5 hours in an electric heating forced air drying oven, heated to 800 ℃ in vacuum or inert gas atmosphere, kept warm for 20 minutes, and then naturally cooled to room temperature.

The implementation effect is as follows: good spreading of the glass coating on the magnet surface was observed, indicating good wetting properties.

Example 3

1. Proportioning and mixing according to the proportion of the components

The raw materials for introducing each oxide were weighed in accordance with the oxide composition of example 3 in table 1. Wherein, SiO₂Introduced in the form of quartz sand, Al₂O₃Introduced in the form of feldspar, B₂O₃Introducing boric acid or borax, MgO in dolomite, CaO in wollastonite, BaO in barium carbonate, Na₂O is introduced in the form of soda ash or borax, MnO is introduced in the form of manganese carbonate, NiO is introduced in the form of nickel protoxide, FeO is introduced in the form of iron oxalate, CuO is introduced in the form of copper carbonate, and CoO is introduced in the form of cobalt carbonate. This conversion process is well known to those skilled in the art. Weighing and mixing the raw materials according to the proportion, and placing the mixture in a V-shaped mixer for uniform mixing.

2. Melting and powdering

And (3) putting the uniformly mixed raw materials into a quartz crucible, heating to 1390 ℃ 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.

3. Preparation of the slurry

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

4. Preparation of glass coatings

The glass coating slurry is brushed on the surface of a samarium cobalt magnet by a brush, dried for 5 hours in an electric heating forced air drying oven, heated to 820 ℃ in vacuum or inert gas atmosphere, kept warm for 10 minutes, and then naturally cooled to room temperature.

The implementation effect is as follows: good spreading of the glass coating on the magnet surface was observed, indicating good wetting properties.

Example 4

1. Proportioning and mixing according to the proportion of the components

The raw materials for introducing each oxide were weighed in accordance with the oxide composition of example 4 in table 1. Wherein, SiO₂Introduced in the form of quartz sand, Al₂O₃Introduced in the form of feldspar, B₂O₃Introducing boric acid or borax, MgO in dolomite, CaO in wollastonite, BaO in barium carbonate, Na₂O is introduced in the form of soda ash or borax, MnO is introduced in the form of manganese carbonate, NiO is introduced in the form of nickel protoxide, FeO is introduced in the form of iron oxalate, CuO is introduced in the form of copper carbonate, and CoO is introduced in the form of cobalt carbonate. This conversion process is well known to those skilled in the art. Weighing and mixing the raw materials according to the proportion, and placing the mixture in a V-shaped mixer for uniform mixing.

2. Melting and powdering

And (3) putting the uniformly mixed raw materials into a quartz crucible, heating to 1390 ℃ 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.

3. Preparation of the slurry

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

4. Preparation of glass coatings

The glass coating slurry is brushed on the surface of a samarium cobalt magnet by a brush, dried for 5 hours in an electric heating forced air drying oven, heated to 820 ℃ in vacuum or inert gas atmosphere, kept warm for 10 minutes, and then naturally cooled to room temperature.

The implementation effect is as follows: good spreading of the glass coating on the magnet surface was observed, indicating good wetting properties.

From the examples disclosed in table 1, it is apparent that in examples 1 and 2, MnO in a weight percent of 4% or more, a glass coating with good wetting can be obtained; comparative example 1 the glass composition contained no transition metal oxides and the glass coating was not wet; when the weight percentage of MnO was less than 4%, in comparative examples 2, 3, 4 and 5, the weight percentage of NiO was more than 1%, the weight percentage of CuO was more than 0.5%, and the weight percentage of CoO was more than 0.5%, the glass coating was not wetted.

As in examples 3 and 4, the glass coating wetted when the MnO weight percent was less than 4%, the NiO weight percent was less than 1%, the CuO weight percent was less than 0.5%, and the CoO weight percent was less than 0.5%.

TABLE 1 ingredients and wetting of examples and comparative examples