High-strength insulator and preparation method thereof

Abstract

The invention relates to the technical field of insulators, and provides a high-strength insulator and a preparation method thereof.The high-strength insulator is prepared from, by weight, 20-30 parts of aluminum oxide, 10-15 parts of kaolin, 6-10 parts of aluminum nitride, 15-20 parts of mullite, 5-10 parts of mica powder, 3-6 parts of titanium dioxide and 10-15 parts of modified silicon nitride whiskers; the modified silicon nitride whiskers are obtained by modifying silicon nitride whiskers with rare earth oxide. According to the technical scheme, the problem of low insulator strength in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of insulators, and in particular to a high-strength insulator and a preparation method thereof. Background Art

[0002] Insulators are an indispensable part of electrical equipment and power systems. They play a vital role in ensuring safe power transmission, normal operation of electrical equipment, and personnel safety. In overhead transmission lines, the primary function of insulators is to effectively isolate live conductors from poles and towers (grounding structures). Without the insulating barrier of insulators, current will flow into the earth through the poles and towers, which will cause the power to be unable to be transmitted normally and cause short circuit failures in the power system. In addition, insulators need to withstand a variety of mechanical loads. Wind load is a major factor. In windy weather, the conductors on overhead lines will be affected by wind, and insulators must withstand the resulting tension, pressure, and bending moment. In cold areas or special climatic conditions, ice may form on the conductors, which not only increases the weight of the conductors, but also increases the windward area, thereby greatly increasing the mechanical load on the insulators. In substations, the insulators of some large electrical equipment must also withstand the weight of the equipment itself and possible vibrations. Therefore, insulators must have sufficient strength to cope with these complex load conditions to ensure the normal operation of power systems and related facilities. Summary of the invention

[0003] The present invention provides a high-strength insulator and a preparation method thereof, which solves the problem of poor insulator strength in the related art.

[0004] The technical solution of the present invention is as follows: The invention provides a high-strength insulator, comprising the following raw materials in parts by weight: 20-30 parts of aluminum oxide, 10-15 parts of kaolin, 6-10 parts of aluminum nitride, 15-20 parts of mullite, 5-10 parts of mica powder, 3-6 parts of titanium dioxide, and 10-15 parts of modified silicon nitride whiskers; the modified silicon nitride whiskers are obtained by modifying silicon nitride whiskers with rare earth oxides.

[0005] As a further technical solution, the crystal form of the silicon nitride whiskers is β phase.

[0006] As a further technical solution, the rare earth oxide includes one or more of cerium dioxide, lanthanum trioxide, and yttrium trioxide.

[0007] As a further technical solution, the rare earth oxide is lanthanum trioxide.

[0008] In the present invention, the silicon nitride whisker is modified by limiting lanthanum trioxide, so that the strength of the insulator is further improved.

[0009] As a further technical solution, the added amount of the rare earth oxide is 5% to 9% of the mass of the silicon nitride whisker.

[0010] As a further technical solution, the method for preparing the modified silicon nitride whisker comprises the following steps: ball-milling the silicon nitride whisker and the rare earth oxide to obtain the modified silicon nitride whisker.

[0011] As a further technical solution, the ball milling time is 1 to 2 hours.

[0012] As a further technical solution, the silicon nitride whiskers are carboxylated silicon nitride whiskers.

[0013] In the present invention, the strength of the insulator is further improved by limiting the silicon nitride whiskers to carboxylated silicon nitride whiskers.

[0014] As a further technical solution, the carboxylated silicon nitride whiskers are obtained by modifying the silicon nitride whiskers with carboxyl compounds.

[0015] As a further technical solution, the mass of the carboxyl-containing compound is 1% to 3% of the mass of the silicon nitride whisker.

[0016] As a further technical solution, the carboxyl-containing compound is 3-carboxymethyl-1-adamantanecarboxylic acid.

[0017] In the present invention, the strength of the insulator is further improved by limiting the carboxyl group-containing compound to 3-carboxymethyl-1-adamantanecarboxylic acid.

[0018] As a further technical solution, the method for preparing the carboxylated silicon nitride whisker comprises the following steps: dissolving a carboxyl-containing compound in water, adding silicon nitride whiskers for modification, and obtaining the carboxylated silicon nitride whiskers after drying.

[0019] As a further technical solution, the modification temperature is 50° C. and the modification time is 6 hours.

[0020] The present invention also provides a method for preparing a high-strength insulator, comprising the following steps: S1, mixing the raw materials of each component to obtain a premix; S2, ball-milling the premix and water, and then pressing and molding to obtain a blank; S3. Dry, calcine and cool the blank to obtain a high-strength insulator.

[0021] As a further technical solution, the mass ratio of the premix to water is 1:1.1~1.3.

[0022] The working principle and beneficial effects of the present invention are: In the present invention, alumina is added to the insulator components to make the insulator have better hardness, and kaolin is added to be matched with other raw materials to fill the gaps between the raw material particles, thereby improving the density of the insulator and enhancing the strength of the insulator. The addition of silicon nitride whiskers modified with rare earth oxides further enhances the mechanical properties of the insulator, thereby solving the problem of low strength and easy breakage of the insulator under heavy loads. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the following examples and comparative examples: α-phase silicon nitride whiskers, diameter: 0.2~0.6μm, length: 10~50μm; β-phase silicon nitride whiskers, diameter: 0.2~1.0μm, length: 5~10μm; lanthanum trioxide, particle size: 50nm; cerium dioxide, particle size: 50nm; yttrium trioxide, particle size: 50nm.

[0025] Example 1 A method for preparing a high-strength insulator comprises the following steps: S1, 20 parts of aluminum oxide, 10 parts of kaolin, 6 parts of aluminum nitride, 15 parts of mullite, 5 parts of mica powder, 3 parts of titanium dioxide, and 10 parts of modified silicon nitride whiskers are mixed to obtain a premix; S2, ball-milling the premix and water (the mass ratio of the premix to water is 1:1.1), and then pressing and molding to obtain a blank; S3. Dry, calcine and cool the blank to obtain a high-strength insulator.

[0026] The preparation method of modified silicon nitride whisker comprises the following steps: 30g of α-phase silicon nitride whisker and 1.5g of cerium dioxide are ball-milled and mixed for 1 hour to obtain modified silicon nitride whisker.

[0027] Example 2 A method for preparing a high-strength insulator comprises the following steps: S1, 25 parts of aluminum oxide, 12 parts of kaolin, 8 parts of aluminum nitride, 17 parts of mullite, 8 parts of mica powder, 4 parts of titanium dioxide, and 12 parts of modified silicon nitride whiskers are mixed to obtain a premix; S2, ball-milling the premix and water (the mass ratio of the premix to water is 1:1.2), and then pressing and molding to obtain a blank; S3. Dry, calcine and cool the blank to obtain a high-strength insulator.

[0028] The preparation method of modified silicon nitride whisker comprises the following steps: 30g of α-phase silicon nitride whisker and 2.1g of cerium dioxide are ball-milled and mixed for 2h to obtain modified silicon nitride whisker.

[0029] Example 3 A method for preparing a high-strength insulator comprises the following steps: S1, 30 parts of aluminum oxide, 15 parts of kaolin, 10 parts of aluminum nitride, 20 parts of mullite, 10 parts of mica powder, 6 parts of titanium dioxide, and 15 parts of modified silicon nitride whiskers are mixed to obtain a premix; S2, ball-milling the premix and water (the mass ratio of the premix to water is 1:1.3), and then pressing and molding to obtain a blank; S3. Dry, calcine and cool the blank to obtain a high-strength insulator.

[0030] The preparation method of modified silicon nitride whisker comprises the following steps: 30g of α-phase silicon nitride whisker and 2.7g of cerium dioxide are ball-milled and mixed for 2h to obtain modified silicon nitride whisker.

[0031] Example 4 The only difference between this embodiment and embodiment 1 is that the α-phase silicon nitride whiskers are replaced with an equal amount of β-phase silicon nitride whiskers.

[0032] Example 5 The only difference between this embodiment and embodiment 4 is that cerium dioxide is replaced by an equal amount of yttrium trioxide.

[0033] Example 6 The only difference between this embodiment and embodiment 4 is that cerium dioxide is replaced by an equal amount of lanthanum trioxide.

[0034] Example 7 The only difference between this embodiment and embodiment 6 is that the method for preparing modified silicon nitride whiskers comprises the following steps: A1. Dissolve 0.4 g of 3-carboxymethyl-1-adamantanecarboxylic acid in 300 mL of deionized water, add 40 g of β-phase silicon nitride whiskers and mix, add to 50° C. and stir for 6 h, and obtain carboxylated silicon nitride whiskers after drying; A2. Take 30 g of carboxylated silicon nitride whiskers and 1.5 g of lanthanum trioxide and mix them by ball milling for 1 hour to obtain modified silicon nitride whiskers.

[0035] Example 8 The only difference between this embodiment and embodiment 7 is that the added amount of 3-carboxymethyl-1-adamantanecarboxylic acid is 0.8 g.

[0036] Example 9 The only difference between this embodiment and embodiment 7 is that the added amount of 3-carboxymethyl-1-adamantanecarboxylic acid is 1.2 g.

[0037] Comparative Example 1 The only difference between this comparative example and Example 1 is that the modified silicon nitride whiskers are replaced with an equal amount of silicon nitride whiskers.

[0038] Comparative Example 2 The only difference between this comparative example and Example 1 is that cerium dioxide is replaced by an equal amount of magnesium oxide.

[0039] The flexural strength of the insulators prepared in Examples 1 to 9 and Comparative Examples 1 to 2 was measured according to the test method in GB / T 4741-1999 “Test Method for Flexural Strength of Ceramic Materials”. The test results are shown in Table 1.

[0040] Table 1 Insulator performance test results

[0041] Compared with Example 1, the silicon nitride whiskers in Comparative Example 1 were not modified, and the silicon nitride whiskers in Comparative Example 2 were modified with magnesium oxide. As a result, the bending strength of the insulators prepared in Comparative Examples 1 and 2 was lower than that in Example 1, indicating that when the silicon nitride whiskers were modified with rare earth oxides, the bending strength of the insulators could be improved.

[0042] Compared with Example 1, the crystal form of the silicon nitride whiskers in Example 4 is β phase. As a result, the bending strength of the insulator prepared in Example 4 is higher than that in Example 1, indicating that when the silicon nitride whiskers are in β phase, the bending strength of the insulator can be further improved.

[0043] Compared with Example 4, the rare earth oxide in Example 5 is yttrium trioxide, and the rare earth oxide in Example 6 is lanthanum trioxide. As a result, the bending strength of the insulator prepared in Example 6 is higher than that of Examples 4 and 5, indicating that when lanthanum trioxide is used to modify silicon nitride whiskers, the bending strength of the insulator can be further improved.

[0044] Compared with Example 6, in Examples 7 to 9, 3-carboxymethyl-1-adamantanecarboxylic acid is used to first modify silicon nitride whiskers to obtain carboxylated silicon nitride whiskers, and then modified with lanthanum trioxide. As a result, the bending strength of the insulators prepared in Examples 7 to 9 is higher than that in Example 6, indicating that when 3-carboxymethyl-1-adamantanecarboxylic acid is used to first modify silicon nitride whiskers to obtain carboxylated silicon nitride whiskers, and then modified with lanthanum trioxide, the bending strength of the insulator can be further improved.

[0045] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high strength insulator, characterized in that: The raw materials include the following components in parts by weight: 20-30 parts of aluminum oxide, 10-15 parts of kaolin, 6-10 parts of aluminum nitride, 15-20 parts of mullite, 5-10 parts of mica powder, 3-6 parts of titanium dioxide, and 10-15 parts of modified silicon nitride whiskers; the modified silicon nitride whiskers are obtained by modifying silicon nitride whiskers with rare earth oxides.

2. A high strength insulator according to claim 1, characterized in that: The crystal form of the silicon nitride whisker is β phase.

3. A high strength insulator according to claim 1, characterized in that: The rare earth oxide includes one or more of cerium dioxide, lanthanum trioxide, and yttrium trioxide.

4. A high strength insulator according to claim 3, characterized in that: The rare earth oxide is lanthanum trioxide.

5. The high strength insulator according to claim 1, characterized in that: The silicon nitride whiskers are carboxylated silicon nitride whiskers.

6. A high strength insulator according to claim 5, characterized in that: The carboxylated silicon nitride whiskers are obtained by modifying the silicon nitride whiskers with carboxyl compounds.

7. A high strength insulator according to claim 6, characterized in that: The carboxyl-containing compound is 3-carboxymethyl-1-adamantanecarboxylic acid.

8. The high strength insulator according to claim 6, characterized in that: The method for preparing the carboxylated silicon nitride whisker comprises the following steps: dissolving a carboxyl compound in water, adding silicon nitride whiskers for modification, and drying to obtain the carboxylated silicon nitride whiskers.

9. The method for preparing a high-strength insulator according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, mixing the raw materials of each component to obtain a premix; S2, ball-milling the premix and water, and then pressing and molding to obtain a blank; S3. Dry, calcine and cool the blank to obtain a high-strength insulator.

10. The method for preparing a high-strength insulator according to claim 9, characterized in that: The mass ratio of the premix to water is 1:1.1-1.3.

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