High-voltage direct-current relay ceramic and preparation method thereof

Abstract

The application relates to the field of ceramic materials, in particular to a high-voltage direct-current relay ceramic and a preparation method thereof, which is made of alumina powder, a sintering aid and a binder; the binder is composed of hydrogen-containing ethenyl silicone resin monomers and a transition metal organic complex; the ceramic can be applied in new energy vehicles, can effectively control and protect high-voltage direct-current circuits in electric vehicles, and ensures the safe use of the batteries.

Description

Technical Field

[0001] This invention relates to the field of ceramic materials, specifically to a high-voltage DC relay ceramic and its preparation method. Background Technology

[0002] Ceramic materials possess excellent insulation properties, can withstand high voltages, exhibit good chemical corrosion resistance and packaging reliability, and are less affected by corrosive media such as acids and alkalis. Therefore, ceramic high-voltage DC relays are gradually replacing epoxy resin high-voltage DC relays in new energy vehicles. Binders play a crucial role in the ceramic material forming process. Currently, polyvinyl alcohol or polyvinyl butyral are commonly used as binders for ceramic materials, with few reports of using silicone resins as binders. Summary of the Invention

[0003] Purpose of the invention: To address the above-mentioned technical problems, this invention proposes a high-voltage DC relay ceramic and its preparation method.

[0004] The technical solution adopted is as follows:

[0005] A high-voltage DC relay ceramic is made of alumina powder, sintering aid and binder;

[0006] The adhesive is composed of hydrogen-containing vinyl silicone resin monomers and transition metal organic complexes.

[0007] Furthermore, the mass ratio of the hydrogen-containing vinyl organosilicon resin monomer to the transition metal organo-complex is 100:1-5.

[0008] Furthermore, the mass ratio of the alumina powder, sintering aid, and binder is 100:1-5:1-3.

[0009] Furthermore, the sintering aid is composed of manganese dioxide, titanium dioxide, magnesium oxide, and rare earth oxides.

[0010] Furthermore, the mass ratio of manganese dioxide, titanium dioxide, magnesium oxide and rare earth oxide is 1-5:1-5:1-5:1-5.

[0011] Furthermore, the rare earth oxide is lanthanum oxide.

[0012] Furthermore, the preparation method of the hydrogen-containing vinyl organosilicon resin monomer is as follows:

[0013] Dissolve triethoxysilane and vinyltriethoxysilane in anhydrous ethanol, add hydrochloric acid aqueous solution, hydrolyze at 20-40℃ for 1-5 hours, and then distill under reduced pressure.

[0014] Furthermore, the transition metal organometallic complex is an iron organometallic complex.

[0015] Furthermore, the iron organic complex is hydrazine carbonyl ferrocene, and the CAS number of the triethoxysilane is 12153-28-5.

[0016] This invention also provides a method for preparing high-voltage DC relay ceramics:

[0017] Using anhydrous ethanol as a ball milling aid, alumina powder and sintering aid are mixed and ball milled. Then, hydrogen-containing vinyl organosilicon resin monomer and transition metal organic complex are added. After thorough stirring, the anhydrous ethanol is removed by heating to obtain a mixed powder. The mixed powder is added to a mold and pressed into a green blank. Finally, the green blank is sintered.

[0018] Furthermore, during sintering, the temperature is first increased to 250-300℃ at a rate of 5-10℃ / min and held for 60-120min, then increased to 600-650℃ at a rate of 5-10℃ / min and held for 120-180min, and finally increased to 1350-1400℃ at a rate of 1-5℃ / min and held for 120-180min.

[0019] It has the following beneficial effects:

[0020] This invention provides a high-voltage DC relay ceramic. The sintering aid, through liquid-phase activation, solid solution strengthening, grain boundary pinning, and grain boundary stabilization, synergistically achieves low-temperature, high-density sintering of alumina and excellent mechanical properties. The hydrogen-containing vinyl organosilicon resin monomer undergoes low-crosslinking curing during heating, followed by further self-crosslinking via hydrosilylation under the catalysis of a transition metal-organic complex. This forms a three-dimensional network structure with adhesive properties between ceramic particles. This three-dimensional network structure acts as a bridge between forming and sintering, providing sufficient mechanical strength to the green body. During high-temperature sintering, it decomposes into silica, which fills grain boundary gaps, significantly reducing the risk of porosity formation. It also has the advantages of low residual carbon content and low shrinkage. Compared to commercially available organosilicon resin binders, the binder component of this invention significantly improves the mechanical properties of the high-voltage DC relay ceramic and effectively reduces shrinkage during sintering. When applied to new energy vehicles, it can effectively control and protect the high-voltage DC circuit in electric vehicles, ensuring the safe use of the battery. Attached Figure Description

[0021] Figure 1 The image shows a cross-sectional SEM image of the high-voltage DC relay ceramic prepared in Example 1.

[0022] Figure 2 This describes the curing process of the hydrogen-containing vinyl silicone resin monomer in Example 1. Detailed Implementation

[0023] Unless otherwise specified in the examples, the conditions were performed under standard conditions or as recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products. Techniques not mentioned in this invention refer to existing technologies. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.

[0024] Example 1:

[0025] A high-voltage DC relay ceramic is made of alumina powder, manganese dioxide, titanium dioxide, magnesium oxide, lanthanum oxide and binder in a mass ratio of 100:0.5:0.5:1:0.5:1;

[0026] The adhesive is composed of hydrogen-containing vinyl silicone resin monomers and hydrazine carbonyl ferrocene in a mass ratio of 100:1.

[0027] The preparation method of hydrogen-containing vinyl organosilicon resin monomer is as follows:

[0028] Dissolve 82.2g of triethoxysilane and 19g of vinyltriethoxysilane in 150ml of anhydrous ethanol. Slowly add 35.1g of a pre-prepared 0.1mol / L hydrochloric acid aqueous solution to the system. After the addition is complete, hydrolyze the solution in a 30℃ water bath for 5h. Then, remove the anhydrous ethanol and water by vacuum distillation.

[0029] The above-mentioned method for preparing high-voltage DC relay ceramics:

[0030] Using anhydrous ethanol as a ball milling aid, alumina powder, manganese dioxide, titanium dioxide, magnesium oxide, and lanthanum oxide were added to the ball mill jar of a planetary ball mill and mixed and ball milled for 10 hours. Then, hydrogen-containing vinyl organosilicon resin monomer and hydrazine carbonyl ferrocene were added, and after thorough stirring, the anhydrous ethanol was removed by vacuum distillation to obtain a mixed powder. The mixed powder was added to a mold and pressed into a green blank under 50 MPa. The green blank was placed in a sintering furnace and heated to 300°C at a rate of 10°C / min and held for 120 min in an air atmosphere. Then, the temperature was increased to 650°C at a rate of 5°C / min and held for 180 min. Finally, the temperature was increased to 1350°C at a rate of 1°C / min and sintered for 180 min.

[0031] Example 2:

[0032] A high-voltage DC relay ceramic is made of alumina powder, manganese dioxide, titanium dioxide, magnesium oxide, lanthanum oxide and binder in a mass ratio of 100:0.5:0.5:1:0.5:2.

[0033] The adhesive is composed of hydrogen-containing vinyl silicone resin monomers and hydrazine carbonyl ferrocene in a mass ratio of 100:1.

[0034] The preparation method of hydrogen-containing vinyl organosilicon resin monomer is as follows:

[0035] Dissolve 82.2g of triethoxysilane and 19g of vinyltriethoxysilane in 150ml of anhydrous ethanol. Slowly add 35.1g of a pre-prepared 0.1mol / L hydrochloric acid aqueous solution to the system. After the addition is complete, hydrolyze the solution in a 30℃ water bath for 5h. Then, remove the anhydrous ethanol and water by vacuum distillation.

[0036] The above-mentioned method for preparing high-voltage DC relay ceramics:

[0037] Using anhydrous ethanol as a ball milling aid, alumina powder, manganese dioxide, titanium dioxide, magnesium oxide, and lanthanum oxide were added to the ball mill jar of a planetary ball mill and mixed and ball-milled for 10 hours. Then, hydrogen-containing vinyl silicone resin monomer and hydrazine carbonyl ferrocene were added, and after thorough stirring, the anhydrous ethanol was removed under reduced pressure to obtain a mixed powder. The mixed powder was added to a mold and pressed into a green blank under 50 MPa. The green blank was placed in a sintering furnace, and under an air atmosphere, the temperature was first increased to 300℃ at a rate of 10℃ / min and held for 120 min, then increased to 650℃ at a rate of 5℃ / min and held for 180 min, and finally increased to 1350℃ at a rate of 1℃ / min and sintered for 180 min. The cross-sectional SEM image is shown below. Figure 1 As shown, the internal density is relatively high.

[0038] Example 3:

[0039] A high-voltage DC relay ceramic is made of alumina powder, manganese dioxide, titanium dioxide, magnesium oxide, lanthanum oxide and binder in a mass ratio of 100:0.5:0.5:1:0.5:3.

[0040] The adhesive is composed of hydrogen-containing vinyl silicone resin monomers and hydrazine carbonyl ferrocene in a mass ratio of 100:1.

[0041] The preparation method of hydrogen-containing vinyl organosilicon resin monomer is as follows:

[0042] Dissolve 82.2g of triethoxysilane and 19g of vinyltriethoxysilane in 150ml of anhydrous ethanol. Slowly add 35.1g of a pre-prepared 0.1mol / L hydrochloric acid aqueous solution to the system. After the addition is complete, hydrolyze the solution in a 30℃ water bath for 5h. Then, remove the anhydrous ethanol and water by vacuum distillation.

[0043] The above-mentioned method for preparing high-voltage DC relay ceramics:

[0044] Using anhydrous ethanol as a ball milling aid, alumina powder, manganese dioxide, titanium dioxide, magnesium oxide, and lanthanum oxide were added to the ball mill jar of a planetary ball mill and mixed and ball milled for 10 hours. Then, hydrogen-containing vinyl organosilicon resin monomer and hydrazine carbonyl ferrocene were added, and after thorough stirring, the anhydrous ethanol was removed by vacuum distillation to obtain a mixed powder. The mixed powder was added to a mold and pressed into a green blank under 50 MPa. The green blank was placed in a sintering furnace and heated to 300°C at a rate of 10°C / min and held for 120 min in an air atmosphere. Then, the temperature was increased to 650°C at a rate of 5°C / min and held for 180 min. Finally, the temperature was increased to 1350°C at a rate of 1°C / min and sintered for 180 min.

[0045] Comparative Example 1:

[0046] The method is basically the same as in Example 1, except that HC-1801B solvent-based methylphenyl silicone resin (Zhejiang Hongchuang New Materials) is used instead of the binder.

[0047] Comparative Example 2:

[0048] It is basically the same as Example 1, except that manganese dioxide is not added.

[0049] Comparative Example 3:

[0050] It is basically the same as Example 1, except that titanium dioxide is not added.

[0051] Comparative Example 4:

[0052] It is basically the same as Example 1, except that magnesium oxide is not added.

[0053] Comparative Example 5:

[0054] It is basically the same as Example 1, except that lanthanum oxide is not added.

[0055] Performance testing

[0056] Ceramic samples were prepared according to the methods in Examples 1-3 and Comparative Examples 1-5 of the present invention and their performance was tested.

[0057] The bulk density of the sample was calculated using Archimedes' method of water displacement.

[0058] Measure the length of the sample before and after sintering with vernier calipers, and calculate the shrinkage rate according to the following formula:

[0059] Shrinkage rate = (L0 - L1) / L0

[0060] In the formula, L0 is the sum of the lengths of the green blank in the x, y, and z directions before sintering; L1 is the sum of the lengths of the sample in the x, y, and z directions after sintering.

[0061] The flexural strength of the specimens was determined using the three-point bending method on a universal testing machine. The span was 30 mm, the loading rate was 0.5 mm / min, and the sample size was 3 mm × 4 mm × 35 mm. Five specimens were tested for each data point, and the average value was taken. The test results are shown in Table 1 below.

[0062] Table 1:

[0063] Example 1 3.62 0.13 336.5 Example 2 3.65 0.11 350.3 Example 3 3.61 0.14 329.7 Comparative Example 1 3.28 2.67 266.4 Comparative Example 2 3.40 0.35 301.6 Comparative Example 3 3.37 0.62 284.3 Comparative Example 4 3.32 0.84 274.5 Comparative Example 5 3.55 0.47 305.6

[0064] As shown in Table 1 above, the high-voltage DC relay ceramics prepared by the method of the present invention have excellent mechanical properties and low shrinkage during sintering. Moreover, the mechanical properties show a trend of first increasing and then decreasing with the increase of binder content.

[0065] As can be seen from the comparison between Example 1 and Comparative Example 1, compared with commercially available silicone resin binders, the binder components of the present invention have a greater improvement in the mechanical properties of high voltage DC relay ceramics, and can effectively reduce the shrinkage rate during sintering.

[0066] As can be seen from the comparison between Example 1 and Comparative Examples 2-4, the addition of manganese dioxide, titanium dioxide, magnesium oxide and lanthanum oxide plays a positive role in improving the mechanical properties of high voltage DC relay ceramics and reducing the shrinkage rate during sintering.

[0067] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-voltage DC relay ceramic, characterized in that, It is made of alumina powder, sintering aids and binders; The adhesive is composed of hydrogen-containing vinyl organosilicon resin monomers and transition metal organo-complexes; The mass ratio of the hydrogen-containing vinyl organosilicon resin monomer to the transition metal organo-complex is 100:1-5; The mass ratio of the alumina powder, sintering aid and binder is 100:1-5:1-3; The sintering aid is composed of manganese dioxide, titanium dioxide, magnesium oxide and rare earth oxides; The mass ratio of manganese dioxide, titanium dioxide, magnesium oxide and rare earth oxides is 1-5:1-5:1-5:1-5; The preparation method of the hydrogen-containing vinyl organosilicon resin monomer is as follows: Dissolve triethoxysilane and vinyltriethoxysilane in anhydrous ethanol, add hydrochloric acid aqueous solution, hydrolyze at 20-40℃ for 1-5 hours, and then distill under reduced pressure. The transition metal organo-complex is an iron organo-complex; The iron-organic complex is hydrazine-carbonyl ferrocene; The above-mentioned method for preparing high-voltage DC relay ceramics: Using anhydrous ethanol as a ball milling aid, alumina powder and sintering aid are mixed and ball milled. Then, hydrogen-containing vinyl organosilicon resin monomer and transition metal organic complex are added. After thorough stirring, the anhydrous ethanol is removed by heating to obtain a mixed powder. The mixed powder is added to a mold and pressed into a green blank. Finally, the green blank is sintered. During sintering, first raise the temperature to 250-300℃ at a rate of 5-10℃ / min and hold for 60-120min, then raise the temperature to 600-650℃ at a rate of 5-10℃ / min and hold for 120-180min, and finally raise the temperature to 1350-1400℃ at a rate of 1-5℃ / min and hold for 120-180min.

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