Carbon ceramic resistor insulating layer, preparation method and application thereof

Abstract

The invention belongs to the technical field of electronic components, and discloses a carbon ceramic resistor insulating layer, a preparation method and application thereof, and the preparation method comprises the following steps: slurry preparation; performing application; and sintering to obtain the carbon ceramic composite resistor and the carbon ceramic resistor insulating layer thereof. According to the invention, bismuth oxide is introduced to cooperate with other components, and the slurry ratio and the sintering process are optimized, so that the insulating layer with high densification degree has a dynamic damage repair mechanism, and the self-repairability, temperature resistance and stability of the insulating layer of the carbon ceramic resistor are synchronously improved; the technical problem that a traditional carbon ceramic resistor is prone to insulation failure due to microcrack propagation under the extreme working condition is effectively solved, the resistor can be suitable for high-voltage, high-frequency and high-temperature extreme working conditions, the service life of the carbon ceramic resistor is greatly prolonged, and the application range of the carbon ceramic resistor is widened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic components, in particular to a carbon ceramic resistor insulating layer, a preparation method and application thereof. BACKGROUND

[0002] Carbon ceramic resistors are widely used in the electrical field, and the performance of the insulating layer is crucial to their safety and stability. As a new type of resistor material, carbon ceramic resistors have excellent high-temperature resistance, corrosion resistance, and high-energy resistance, and are widely used in power equipment, lightning protection devices, and high-energy physics experimental devices. However, the performance of the insulating layer of traditional carbon ceramic resistors still has deficiencies, especially under extreme working conditions (such as large current impact and thermal cycling), which can easily lead to insulating failure due to microcrack propagation and other dynamic damage. Existing research results show that the generation of microcracks is mainly due to insufficient bonding strength between ceramic particles and thermal stress concentration. Therefore, conventional techniques for improving the performance of the insulating layer of carbon ceramic resistors mainly consider material selection, process optimization, and structure design, and lack effective design of the dynamic damage repair mechanism of the insulating layer.

[0003] For example, CN111627627A discloses a high-resistance layer for a carbon ceramic linear resistor and a preparation method thereof. The high-resistance layer is prepared by mixing mullite powder, clay, chromium oxide, and glass powder as raw materials, and adding deionized water. After ball milling, a porous structure is formed after high-temperature sintering. This structure is beneficial for SF6 insulating gas to enter the high-resistance layer and the ceramic body of the resistor, thereby improving its resistance to voltage impact. However, the densification degree of the porous structure of the high-resistance layer is low (porosity is greater than 10%), which cannot achieve dynamic damage repair of the insulating layer, cannot simultaneously improve the insulating performance, temperature resistance, and stability of the carbon ceramic resistor, and thus cannot effectively prolong the service life of the carbon ceramic resistor or effectively broaden its application range. SUMMARY

[0004] To overcome the deficiencies in the above background art, the present application provides a carbon ceramic resistor insulating layer, a preparation method and application thereof. Through the synergistic improvement of components, ratio, and preparation method, bismuth oxide is introduced to cooperate with other components, the slurry ratio and sintering process are optimized, the insulating layer with high densification degree (significantly reduced porosity) has a dynamic damage repair mechanism, and the self-repairing property, temperature resistance, and stability of the carbon ceramic resistor insulating layer are simultaneously improved. This effectively solves the technical problem of insulating failure of traditional carbon ceramic resistors due to microcrack propagation under extreme working conditions, is suitable for high-voltage, high-frequency, and high-temperature extreme working conditions, greatly prolongs the service life of the carbon ceramic resistor, and broadens its application range.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions: A preparation method of carbon ceramic resistor insulating layer, comprising the following steps: (1) Slurry preparation Take bismuth oxide 5%~20%, alumina 20%~50%, bauxite 15%~40%, clay 20%~40% by mass percentage, mix, and then add 2%~5% polyvinyl alcohol or phenolic resin as a binder and 20%~35% deionized water or ethanol as a solvent; Wet ball mill the mixture to obtain a uniform slurry with a fineness of ≤5 μm, and add an additive solvent and a thickening agent to adjust the viscosity of the slurry to 1500~3000 mPa·s; (2) Application Pretreat the carbon ceramic resistor substrate, and wipe the surface with alcohol or acetone to remove oil stains and impurities; Apply the slurry to the surface of the carbon ceramic resistor substrate by spraying or spin coating, control the thickness of a single layer and the total thickness to reach the set value, and form a slurry coating layer; Place the carbon ceramic resistor substrate after application in an oven for drying, and volatilize the solvent in the slurry coating layer; (3) Sintering Glue removal by heating: heat at a rate of 0.3~0.8 ℃ / min to 400 ℃, and keep the temperature for 2~4 hours to fully decompose the organic components in the slurry coating layer; Sintering densification: after glue removal, heat at a rate of 2~6 ℃ / min to 550~650 ℃, and keep the temperature for 1~3 hours to form necking between ceramic particles and to form a liquid phase of bismuth oxide in the slurry coating layer at 400~600 ℃, which reacts with the carbon ceramic resistor substrate to improve the density; Cooling: after sintering, cool to room temperature in the furnace, and pass nitrogen or argon gas throughout the process to prevent oxidation, and obtain a carbon ceramic composite resistor and a carbon ceramic resistor insulating layer thereof.

[0006] A carbon ceramic resistor insulating layer is prepared by the preparation method, the porosity of the carbon ceramic resistor insulating layer is <5%, the volume resistivity is ≥8×10¹² Ω·cm, the breakdown field strength is ≥15 kV / mm, and the bonding strength with the carbon ceramic resistor substrate is ≥40 MPa; under the working conditions of high current impact or thermal cycling, the edge microcracks of the insulating layer are filled and repaired by semi-molten bismuth oxide, and long-term stability is maintained.

[0007] A carbon ceramic composite resistor comprises the carbon ceramic resistor insulating layer and a carbon ceramic resistor substrate combined therewith, the carbon ceramic resistor insulating layer coats the carbon ceramic resistor substrate, and after sintering densification, the carbon ceramic resistor insulating layer can significantly improve the insulation performance, temperature resistance and stability of the carbon ceramic resistor.

[0008] The application of a carbon ceramic composite resistor in an extreme working environment of high temperature, high pressure and high energy impact.

[0009] Compared with the prior art, the present application has the following advantages and remarkable features: 1、The present application improves the composition, ratio and preparation method of the insulation layer, introduces bismuth oxide in a certain proportion, makes the insulation layer with high densification degree have a dynamic damage repair mechanism, makes the porosity of the insulation layer less than 5%, and improves the insulation performance, temperature resistance and stability of the insulation layer, thereby prolonging the service life of the carbon ceramic resistor and widening the application range of the carbon ceramic resistor; wherein the bismuth oxide in a certain proportion plays a dual role in the sintering process, one is microstructure optimization: as a low-temperature eutectic, bismuth oxide forms a liquid phase at 400-600 DEG C, promotes the rearrangement of inorganic insulation layer particles, reduces the densification temperature of traditional solid-phase sintering by 150-300 DEG C, and significantly reduces the porosity; the other is interface bonding enhancement: bismuth oxide and silicon oxide, aluminum oxide and other oxides in the carbon ceramic matrix have eutectic reaction to generate eutectic mixture, so that the interface bonding strength is improved.

[0010] 2、The carbon ceramic resistor insulation layer and the preparation method thereof provided by the present application synchronously optimize the ratio, structure and process by introducing bismuth oxide in a certain proportion, and significantly improve the self-repairing property and stability of the carbon ceramic resistor insulation layer. The addition of bismuth oxide can optimize the microstructure of the insulation layer, reduce defects such as pores and cracks, and improve the densification and uniformity of the insulation layer. Especially in the process of large current impact, the microcracks caused by the rapid heating and expansion of the edge of the resistor sheet will be filled and repaired by the semi-molten bismuth oxide, maintaining the stability of the insulation layer, effectively preventing the aging and breakdown of the insulation layer, so that the carbon ceramic resistor prepared thereby can be widely applied to extreme working condition scenes such as high temperature, high pressure and high energy impact, and meet the higher performance requirements of power equipment, lightning protection devices and high energy physics experiment device manufacturing.

[0011] The above is a summary of the technical scheme of the present application, which will be further described in combination with the specific embodiments and the drawings. DETAILED DESCRIPTION

[0012] Figure 1 is the SEM diagram of the combination of the carbon ceramic resistor insulation layer prepared by the present application embodiment 1 and the carbon ceramic resistor body substrate; Figure 2 is the SEM diagram of the combination of the carbon ceramic resistor insulation layer prepared by the present application embodiment 2 and the carbon ceramic resistor body substrate; Figure 3 is the SEM diagram of the combination of the carbon ceramic resistor insulation layer prepared by the present application embodiment 3 and the carbon ceramic resistor body substrate. DETAILED DESCRIPTION

[0013] In order to make the technical problems, technical schemes and beneficial effects of the present application more clear, the present application will be further described in detail in combination with the drawings.

[0014] Basic embodiment A preparation method of a carbon ceramic resistor insulating layer, comprising the following steps: (1) Slurry preparation Take bismuth oxide 5%~20%, alumina 20%~50%, bauxite 15%~40%, clay 20%~40% by mass percentage, mix, and then add 2%~5% polyvinyl alcohol or phenolic resin as a binder and 20%~35% deionized water or ethanol as a solvent; Perform wet ball milling on the mixture to obtain a uniform slurry with a fineness of ≤5 μm, and add an additive solvent and a thickening agent to adjust the viscosity of the slurry to 1500~3000 mPa·s; (2) Application Pre-treat the carbon ceramic resistor body substrate, and wipe the surface with alcohol or acetone to remove oil stains and impurities; Apply the slurry to the surface of the carbon ceramic resistor body substrate by spraying or spin coating, control the single-layer thickness and the total thickness to reach the set value, and form a slurry coating layer; Place the applied carbon ceramic resistor body substrate in an oven for drying, and slowly volatilize the solvent in the slurry coating layer; When applying by spraying, the spray gun pressure is 0.3~0.5 MPa, the single-layer thickness is controlled to be 20~40 μm, and the total thickness is set to be 80~150 μm according to the resistor chip specifications; (3) Sintering Glue removal by heating: heat at a rate of 0.3~0.8 ℃ / min to 400 ℃, and keep the temperature for 2~4 hours to fully decompose the organic components in the slurry coating layer; Sintering densification: after glue removal, heat at a rate of 2~6 ℃ / min to 550~650 ℃, and keep the temperature for 1~3 hours to form necking between ceramic particles and to promote the solid solution reaction between bismuth oxide in the slurry coating layer and the carbon ceramic resistor body substrate, thereby improving the density; Cooling: after sintering is completed, cool to room temperature in the furnace, and pass nitrogen or argon gas throughout the process to prevent oxidation, thereby obtaining a carbon ceramic composite resistor and a carbon ceramic resistor insulating layer with a dynamic damage repair mechanism.

[0015] A carbon ceramic resistor insulating layer prepared by the above preparation method, wherein the porosity of the carbon ceramic resistor insulating layer is <5%, the volume resistivity is ≥8×10¹² Ω·cm, the breakdown field strength is ≥15 kV / mm, and the bonding strength with the carbon ceramic resistor body is ≥40 MPa; under the conditions of large current impact or thermal cycling, the edge micro-cracks of the insulating layer are filled and repaired by semi-molten bismuth oxide, and long-term stability is maintained.

[0016] The carbon ceramic resistive insulation layer can withstand ≥20 cycles in a thermal shock cycle test at 500~800℃ without developing through cracks or insulation failure.

[0017] A carbon ceramic composite resistor includes a carbon ceramic resistor insulating layer and a carbon ceramic resistor substrate bonded to the carbon ceramic resistor insulating layer. The carbon ceramic resistor insulating layer covers the carbon ceramic resistor substrate and has a dynamic damage repair mechanism after sintering and densification, which can significantly improve the insulation performance, temperature resistance and stability of the carbon ceramic resistor.

[0018] Applications of the carbon ceramic composite resistor in extreme working environments with high temperature, high pressure and high energy impact.

[0019] The following is in conjunction with the appendix Figures 1-3 The following detailed description is provided, along with several specific embodiments; all raw materials used are commercially available.

[0020] Example 1 This embodiment is a specific application of the aforementioned basic embodiment, specifically providing an alumina-based insulating layer for carbon ceramic resistors and its preparation method. By optimizing the slurry ratio and sintering process, a highly dense insulating layer is obtained, and a dynamic damage repair mechanism is formed.

[0021] The method for preparing the carbon ceramic resistive insulating layer includes the following steps: A. Slurry preparation Weigh out 10% bismuth oxide, 35% alumina, 30% bauxite, and 25% kaolin by weight percentage, and dry mix them in a V-type mixer for 30 min. Add 3% polyvinyl alcohol aqueous solution (solid content 8%) and 30% deionized water, transfer to a nylon ball mill jar, and use zirconia beads (5 mm in diameter, ball-to-material ratio 3:1) as the grinding medium. Ball mill at 250 rpm for 16 h, and measure the slurry particle size D50 = 3.2 μm. Add 0.5% hydroxymethyl cellulose to adjust the viscosity to 1200 mPa·s. B. Coating process The carbon-ceramic substrate was ultrasonically cleaned with acetone for 15 minutes and then dried at 120°C. An air spraying method was used, with a spray gun pressure of 0.3 MPa, controlling the single-layer thickness at 30 μm, and repeating the spraying four times to achieve a total thickness of 120 μm. After coating, the substrate was placed in an oven at 80°C for 2.5 hours, with an ambient humidity ≤30%RH.

[0022] C. Sintering process The temperature was increased to 400℃ at 0.5℃ / min and held for 2 hours before the glue was discharged (nitrogen flow rate 5L / min). Then, the temperature was increased to 600℃ at 3℃ / min and held for 2 hours before being cooled to room temperature in the furnace.

[0023] Performance testing The insulating layer prepared in this embodiment has a porosity of 4.58% and is mainly composed of mullite phase, alumina phase, and bismuth-rich phase, with a volume resistivity of 8.2 × 10⁻⁶. 12 The resistance element exhibits a breakdown electric field strength of 15.3 kV / mm and a bonding strength with the substrate of 45 MPa. After 25 cycles of rapid cooling and thermal shock from -50°C to 350°C, the insulation layer maintains a good bond with the substrate without any cracks. The resistance element is subjected to 16 cycles of 500 J·cm. -3 No flashover occurred on the side after being subjected to a 2ms square wave pulse, and the insulation layer showed no visible damage. The microstructure of the bonding between the insulation layer and the resistor body is shown in [see attached image]. Figure 1 As can be seen, the insulation layer is tightly bonded to the resistor body, and no microcracks are generated.

[0024] Example 2 This embodiment is a specific application of the aforementioned basic embodiment, and is basically the same as Embodiment 1. The difference lies in the method for preparing the carbon ceramic resistive insulating layer, which includes the following steps: A. Slurry preparation Weigh out 15% bismuth oxide, 30% alumina, 25% bauxite, and 30% kaolin by weight percentage, and dry mix them in a V-type mixer for 45 min. Add 4% ammonium polyacrylate aqueous solution (solid content 10%) and 25% deionized water, transfer to an alumina ball mill jar, and use zirconia beads (3 mm in diameter, ball-to-material ratio 4:1) as the grinding medium. Ball mill at 200 rpm for 12 h, and measure the slurry particle size D50 = 2.8 μm. Add 0.8% polyacrylamide to adjust the viscosity to 1500 mPa·s.

[0025] B. Coating process The carbon-ceramic substrate was ultrasonically cleaned with acetone and then dried at 150°C. A spin coating method (800 rpm) was used, controlling the single-layer thickness to 25 μm, and the coating was repeated 5 times until a total thickness of 125 μm was achieved. After coating, the substrate was placed in a vacuum drying oven at 60°C for 3 hours, with an ambient humidity ≤20%RH.

[0026] C. Sintering process The temperature was increased to 450℃ at 0.3℃ / min and held for 1.5 hours to remove the binder (argon flow rate 8L / min). Then the temperature was increased to 600℃ at 5℃ / min. During the holding period, a pressure of 2MPa was applied to assist sintering. After holding for 1 hour, the temperature was cooled with the furnace.

[0027] Performance testing The resulting insulating layer has a porosity of 3.11%, a volume resistivity of 1.1 × 10¹³ Ω·cm, a breakdown electric field strength of 18.2 kV / mm, and a bonding strength with the substrate of 52 MPa. After 25 cycles of rapid cooling and thermal shock from -50 to 350℃, the insulating layer showed good bonding with the substrate, and no cracks were found in the insulating layer. The resistive element was subjected to 16 cycles of 525 J·cm. -3The side of the resistance piece does not flashover after being impacted by 2ms square wave pulse energy of 550J·cm-2, and the insulating layer is not damaged.

[0028] Example 3 This example is a specific application of the foregoing base example, which is basically the same as Example 1 or 2, except that the preparation method of the carbon ceramic resistance insulating layer includes the following steps: A. Slurry preparation According to the mass percentage, 12% bismuth oxide, 40% aluminum oxide, 20% bauxite, and 28% kaolin are weighed and dry-mixed in a V-type mixer for 60 minutes. 5% hydroxypropyl methylcellulose aqueous solution (solid content 5%) and 28% deionized water are added and transferred to a nylon ball mill tank. Zirconium oxide beads (diameter 8mm, ball-to-material ratio 2:1) are used as the grinding medium, and planetary ball milling is carried out at 300rpm for 10 hours. The slurry particle size D50 is measured to be 4.1μm. 1% polyethylene glycol is added to adjust the viscosity to 1000mPa·s.

[0029] B. Application process After the carbon ceramic substrate is ultrasonically cleaned with acetone and dried at 100℃, a spin coating method (rotation speed 800rpm) is used to control the single-layer thickness to be 20μm. The coating is repeated 5 times to obtain a total thickness of 100μm. After application, the coating is dried in a 90℃ oven for 1.5 hours in an environment with a humidity of ≤40%RH.

[0030] C. Sintering process The temperature is raised to 350℃ at a rate of 0.8℃ / min, and the glue is removed (nitrogen flow 3L / min) for 3 hours. Then the temperature is raised to 650℃ at a rate of 2℃ / min, and the sample is kept at this temperature for 2 hours before cooling in the furnace.

[0031] Performance test The porosity of the obtained insulating layer is 2.16%, the resistivity is 7.5×10¹²Ω·cm, the breakdown field strength is 14.8kV / mm, and the bonding strength with the substrate is 40MPa. After 25 times of thermal shock cycles of -50~350℃, the insulating layer and the substrate are well bonded, and the insulating layer has no cracks. The resistance piece does not flashover on the side after being impacted by 2ms square wave pulse energy of 550J·cm -3 The insulating layer and the resistance body are combined tightly, and no microcracks are generated. Figure 2 The insulating layer and the resistance body are combined tightly, and no microcracks are generated.

[0032] Comparative example This example uses basically the same proportion and preparation process as Example 1, except that there is no bismuth oxide added in the formula, and the preparation method of the insulating layer includes the following steps: A. Slurry preparation Al2O345%, bauxite 30%, kaolin 25% by mass, placed in a V-type mixer and dry mixed for 30 min. 3% polyvinyl alcohol aqueous solution (solid content 8%) and 30% deionized water were added, and the ball milling process was the same as in Example 1. The slurry particle size D50 was measured to be 4.5 μm.

[0033] B. Application process The process parameters were the same as in Example 1.

[0034] C. Sintering process The process parameters were the same as in Example 1.

[0035] Performance test The porosity of the obtained insulating layer was greater than 10%, and the volume resistivity was 1.1 x 10 13 Ω·cm, the breakdown field strength was 19.1 kV / mm, and the bonding strength with the substrate was 28 MPa. After 25 times of thermal shock cycling at -50~350°C, microcracks appeared at the bonding between the insulating layer and the substrate. After 5 times of 2 ms pulse energy impact of 500 J·cm⁻³, obvious flashover traces appeared on the side surface, and through cracks were observed at the edge of the insulating layer. The microstructure of the bonding between the insulating layer and the resistor body is shown in Figure 3 It can be seen that the bonding between the insulating layer and the resistor body has obvious cracking and cannot be restored after damage, and cannot be dynamically repaired, verifying the necessity of the dynamic repair mechanism of bismuth oxide to thermal shock damage.

[0036] The test results of the comparative example and each example show that, due to the lack of bismuth oxide in the traditional process, solid solution strengthening cannot be performed in the microstructure formation and process, the insulating layer does not have high-temperature melting repair function, leading to poor bonding of the insulating layer, and microcracks appear at the bonding between the insulating layer and the substrate after thermal shock cycling; after the structure is damaged by pulse energy impact, the microcracks are further expanded into through cracks, which cannot be self-healed, verifying the synergy of the key components, process parameters, material structure and performance in the technical scheme of the present application.

[0037] It should be noted that, within the range of the material ratios and process parameters disclosed in the present application, specific values can be selected, and the obtained materials can all achieve the technical effects disclosed in the present application. Therefore, the present application does not list them one by one.

[0038] The above description is only a preferred embodiment of the present application, and does not limit the technical scope of the present application in any way. Therefore, the same or similar technical features as the above-described embodiments of the present application are within the protection scope of the present application.

Claims

1. A method for preparing a carbon ceramic resistive insulating layer, characterized in that, Includes the following steps: (1) Slurry preparation Weigh out 5%~20% bismuth oxide, 20%~50% alumina, 15%~40% bauxite, and 20%~40% clay by mass percentage, mix them, add 2%~5% polyvinyl alcohol or phenolic resin as a binder, and add 20%~35% deionized water or ethanol as a solvent. The above mixture was subjected to wet ball milling to obtain a uniform slurry with a fineness ≤5μm. Solvent and thickener were added to adjust the viscosity of the slurry to 1500~3000mPa·s. (2) Apply coating Pre-treat the carbon ceramic resistor substrate by wiping the surface with alcohol or acetone to remove oil and impurities; The slurry is applied to the surface of the carbon ceramic resistive substrate by spraying or spin coating, and the thickness of the single layer and the total thickness are controlled to reach the set values ​​to form a slurry coating layer. The coated carbon ceramic resistor substrate is placed in an oven to dry, allowing the solvent in the slurry coating layer to evaporate. (3) Sintering Heating and descaling: Heat to 400℃ and maintain the temperature to allow the organic components of the slurry coating to fully decompose; Sintering densification: After debinding, the temperature is raised to 550~650℃ and held to allow necking bonds to form between ceramic particles. At the same time, bismuth oxide in the slurry coating layer undergoes a solid solution reaction with the carbon ceramic resistive matrix, which increases the density. Cooling: After sintering, the furnace is cooled to room temperature in a protective gas atmosphere to obtain a carbon ceramic composite resistor and its carbon ceramic resistor insulation layer.

2. The method for preparing the carbon ceramic resistive insulating layer according to claim 1, characterized in that, In step (1) of the slurry preparation, the mass percentage of bismuth oxide is 5% to 20%. When the percentage is adjusted within this range, the self-healing performance and stability of the carbon ceramic resistive insulation layer will change accordingly.

3. The method for preparing the carbon ceramic resistive insulating layer according to claim 1, characterized in that, In the coating step (2), when the spraying method is used, the spray gun pressure is 0.3~0.5MPa, the single layer thickness is controlled at 20~40μm, and the total thickness is set to 80~150μm according to the specifications of the resistor sheet.

4. The method for preparing the carbon ceramic resistive insulating layer according to claim 1, characterized in that, The sintering step (3) specifically includes: Heating and desizing: Heat to 400℃ at a rate of 0.3~0.8℃ / min and hold for 2~4 hours to fully decompose the organic components of the slurry coating layer; Sintering densification: After debinding, the temperature is raised to 550-650℃ at a rate of 2-6℃ / min and held for 1-3 hours to form necking bonds between ceramic particles. At the same time, bismuth oxide in the slurry coating layer forms a liquid phase at 400-600℃ and undergoes a solid solution reaction with the carbon ceramic resistive matrix to increase density. Cooling: After sintering, the furnace is cooled to room temperature, and nitrogen or argon is introduced throughout the process to prevent oxidation, thus obtaining carbon ceramic composite resistors and their carbon ceramic resistor insulation layers.

5. A carbon ceramic resistive insulating layer, characterized in that, The carbon ceramic resistor insulation layer, prepared by any one of claims 1 to 4, has a porosity of <5%, a volume resistivity of ≥8×10¹²Ω·cm, a breakdown field strength of ≥15kV / mm, and a bonding strength with the carbon ceramic resistor matrix of ≥40MPa. Under high current impact or thermal cycling conditions, the microcracks at the edge of the insulation layer are filled and repaired by semi-molten bismuth oxide, maintaining long-term stability.

6. The carbon ceramic resistive insulating layer according to claim 5, characterized in that, The carbon ceramic resistive insulation layer can withstand ≥20 cycles in a thermal shock cycle test at 500~800℃ without developing through cracks or insulation failure.

7. A carbon ceramic composite resistor, characterized in that, It includes the carbon ceramic resistor insulation layer as described in claim 5 or 6, and the carbon ceramic resistor substrate bonded thereto, wherein the carbon ceramic resistor insulation layer covers the carbon ceramic resistor substrate, and after sintering and densification, it can significantly improve the insulation performance, temperature resistance and stability of the carbon ceramic resistor.

8. The application of the carbon ceramic composite resistor of claim 7 in extreme working environments of high temperature, high pressure and high energy impact.

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