Metal oxide ceramic resistor and process for producing the same

Abstract

The application relates to the field of ceramic resistors, and particularly discloses a metal oxide ceramic resistor which comprises a framework, caps arranged at two ends of the framework and lead wires connected to the caps; the framework contains metal oxides, the metal oxides contain the following raw materials in parts by weight: 5-10 parts of tin oxide; 2-6 parts of nickel oxide; 4-9 parts of zinc oxide; 1-3 parts of residual metal oxides; the residual metal oxides include one or more of iron oxide, copper oxide and manganese oxide; and a preparation method is as follows: S1, oxide fermentation; S2, rubber mixing; S3, sintering; and S4, post-treatment. The metal oxide ceramic resistor can realize low resistance value of the resistor, reduce the brittleness of the resistor, and prevent the resistor from exploding; in addition, the preparation method has the advantages of simple operation and wide application.

Description

Technical Field

[0001] This application relates to the field of ceramic resistors, and more specifically, to a metal oxide ceramic resistor and its preparation process. Background Technology

[0002] A resistor, commonly referred to simply as a resistor in everyday life, is a current-limiting element. The resistance value of a resistor is generally related to temperature, material, length, and cross-sectional area. The main physical characteristic of a resistor is its ability to convert electrical energy into heat energy; it can also be considered an energy-consuming element. Current flowing through it generates internal energy. Resistors typically function as voltage dividers and current dividers in circuits. For signals, both AC and DC signals can pass through resistors.

[0003] In related technologies, resistors have gone through three stages of development: traditional resistors, wire-wound resistors, and solid resistors. Traditional resistors, wire-wound resistors, and solid resistors all include a frame, caps at both ends of the frame, and leads connected to the caps.

[0004] The difference lies in the fact that traditional resistors use a frame made of ordinary ceramic with a functional film, which can be a carbon film, a metal film, or a metal oxide film, processed on its surface. The frame has circumferential grooves on its sidewalls, these grooves being annular and coaxial with the frame. Multiple grooves are arranged side-by-side along the length of the frame. The functional film and the grooves together form a resistor, which conducts electricity via a conductive strip. However, residual impurities can remain within the grooves, causing the functional film to be unable to withstand the load, resulting in adjacent grooves burning out.

[0005] Wire-wound resistors replace grooves by winding resistance wire around the surface of the frame; the smaller the diameter of the resistance wire, the higher the resistance. However, the resistance wire will burn out if it carries an excessive current. Furthermore, during the wire drawing process, the presence of impurities or a smaller diameter at one point compared to other points can also lead to wire burnout. Therefore, both traditional and wire-wound resistors are prone to premature failure.

[0006] To address the problem of early resistor failure, cell-based resistors were developed. Early versions used a carbon rod pressed into a core for conductivity. Later improvements used barium carbonate as the core, but achieving low resistance values ​​was difficult, and the resistors were brittle and prone to explosion. Therefore, there is a need to provide a resistor that overcomes the difficulties in achieving low resistance values ​​and addresses the issues of brittleness and explosiveness. Summary of the Invention

[0007] In order to achieve low resistance values ​​and reduce resistor brittleness, making the resistor less prone to explosion, this application provides a metal oxide ceramic resistor and its preparation process.

[0008] In a first aspect, this application provides a metal oxide ceramic resistor, which adopts the following technical solution:

[0009] A metal oxide ceramic resistor includes a frame, caps disposed at both ends of the frame, and leads connected to the caps; the frame comprises a metal oxide, the metal oxide comprising the following parts by weight of raw materials:

[0010] 5-10 parts of tin oxide;

[0011] 2-6 parts nickel oxide;

[0012] 4-9 parts zinc oxide;

[0013] 1-3 parts of other metal oxides; the other metal oxides include one or more of iron oxide, copper oxide and manganese oxide.

[0014] By adopting the above technical solution, firstly, the skeleton of this application is a conductor, which has high reliability and low resistivity, which is conducive to realizing low resistance value resistors; secondly, the skeleton is a metal oxide, which has high strength; thirdly, the skeleton of this application has good toughness when subjected to overcurrent impact, and compared with ordinary ceramic skeletons, it is not easy to break due to high brittleness, and has excellent pulse resistance performance; moreover, metal oxide has a high ability to absorb energy, and is not prone to explosion problems.

[0015] Secondly, this application provides a method for preparing a metal oxide ceramic resistor, which adopts the following technical solution:

[0016] A process for fabricating a metal oxide ceramic resistor includes the following steps:

[0017] S1. Oxide Awakening: According to the formula, put the raw materials into the reaction vessel and allow them to permeate each other under natural conditions to obtain an interpenetrating mixture;

[0018] S2. Rubber compounding: Take the adhesive and mix the interpenetrating mixture with the adhesive at a mass ratio of 2-6:1-8. After rubber compounding, extrude to obtain rods.

[0019] S3. Sintering: After sintering the rod at 1000-1700℃, a rough skeleton is obtained;

[0020] S4. Post-processing: The outer diameter of the rough skeleton is ground to obtain the refined skeleton; after coating the refined skeleton with silver electrodes, caps are set at both ends, and then leads are connected to the caps. After encapsulation with encapsulating agent, metal oxide ceramic resistor is obtained.

[0021] By adopting the above technical solution, firstly, in step S1, the metal oxides are activated in air and interpenetrate naturally. Then, in step S2, the interpenetrated mixture is bonded and shaped under the action of an adhesive, so as to be extruded into a rod. The rod is then sintered, during which the adhesive is removed at high temperature, and the molecules or atoms in the metal oxide solid particles attract each other. The sintering temperature gives the particles sufficient energy to migrate, causing the metal oxides to bond together, producing particle adhesion, generating strength, densification, and recrystallization, resulting in a rough skeleton with certain strength and toughness. Then, in step S4, the rough skeleton is ground to a specified size to obtain a refined skeleton. Then, silver electrodes are coated, a cap is set, and finally, leads are connected to the cap. After encapsulation, a metal oxide ceramic resistor is obtained.

[0022] Preferably, the mutual permeation treatment in step S1 takes 5-9 days, and the rubber compounding treatment in step S2 takes 2-4 days.

[0023] By adopting the above technical solution, the time of mutual penetration treatment and rubber compounding treatment can be controlled, which helps the metal oxides in the skeleton raw materials to mix and combine evenly, thereby helping to obtain a uniform and stable skeleton, which is conducive to improving the overall performance of metal oxide ceramic resistors.

[0024] Preferably, the encapsulating agent in step S4 is an organosilicon coating.

[0025] By adopting the above technical solutions, silicone coatings have excellent oxidation resistance and UV resistance. Encapsulation with silicone materials can provide good protection for metal oxide ceramic resistors.

[0026] Preferably, the adhesive in step S2 includes polyvinyl alcohol-sodium alginate composite hydrogel or liquid polyvinyl alcohol.

[0027] By adopting the above technical solution, a good bond between metal oxides in the skeleton raw material can be achieved.

[0028] Preferably, the preparation method of the polyvinyl alcohol-sodium alginate composite hydrogel includes the following steps:

[0029] (1) Preparation of polyvinyl alcohol aqueous solution: Mix solid polyvinyl alcohol and water at 70-110℃ to prepare a polyvinyl alcohol aqueous solution with a mass fraction of 5%-15%;

[0030] (2) Preparation of mixed aqueous solution: Sodium alginate powder is added to the polyvinyl alcohol aqueous solution in step S1, and mixed and stirred at 30-70℃ to obtain mixed aqueous solution;

[0031] (3) Preparation of crosslinking agent: Dissolve boric acid and anhydrous calcium chloride in water to prepare a calcium chloride saturated boric acid solution with a mass fraction of 1%-5%, which is the crosslinking agent;

[0032] (4) Reaction: After the mixed aqueous solution is defoamed by ultrasound and poured into a mold to form, it is immersed in the crosslinking agent in step S3 to obtain the immersed body; the immersed body is subjected to cyclic freezing and thawing treatment to obtain polyvinyl alcohol-sodium alginate composite hydrogel.

[0033] By adopting the above technical solution, firstly, a polyvinyl alcohol aqueous solution with a mass fraction of 5%-15% is prepared by controlling a suitable temperature in step (1). Then, sodium alginate powder is added in step (2), and a mixed aqueous solution is obtained after stirring while controlling a suitable temperature. Next, an amphoteric crosslinking agent is prepared in step (3). Finally, a three-dimensional porous polyvinyl alcohol-sodium alginate composite hydrogel is obtained in step (4). When metal oxide particles are mixed with polyvinyl alcohol-sodium alginate composite hydrogel, some of the metal oxide particles enter and distribute in the pores of the porous structure of polyvinyl alcohol-sodium alginate composite hydrogel, increasing the bonding area, thereby improving the bonding strength between the skeleton raw materials, and making the gaps between the metal oxide particles smaller, which helps to improve the density of the skeleton and further increase the strength of the skeleton.

[0034] Preferably, the particle size of the metal oxide is 1-5 μm, and the mass fraction of the calcium chloride saturated boric acid solution in step S3 is 3%.

[0035] By adopting the above technical solution, when the mass fraction of calcium chloride saturated boric acid solution is 3%, it helps to control the pore size of the three-dimensional porous structure within the range of 10-30 μm, which facilitates the entry and bonding of metal oxides.

[0036] Preferably, the metal oxide is spherical.

[0037] By adopting the above technical solution, the spherical metal oxide has good rolling and flow properties, which further facilitates the metal oxide to enter and distribute in the pores of the polyvinyl alcohol-sodium alginate composite hydrogel porous structure.

[0038] In summary, this application has the following beneficial effects:

[0039] 1. Since this application uses metal oxide as the framework of ceramic resistor, the framework as a whole is a conductor, which has high reliability and low resistivity, which is conducive to realizing low resistance resistors; and the framework as a whole is metal oxide, which has high strength; in addition, the framework of this application has good toughness when subjected to overcurrent impact, and is not easy to break due to high brittleness compared with ordinary ceramic frameworks; and metal oxide has a high ability to absorb energy, which is not easy to cause explosion problems.

[0040] 2. The method of this application firstly involves step S1, in which the metal oxides are activated in air and interpenetrate naturally; then, in step S2, the interpenetrated mixture is bonded and shaped under the action of an adhesive to facilitate extrusion into a rod; then, the rod is sintered to obtain a rough skeleton with certain strength and toughness; then, in step S4, the rough skeleton is ground to a specified size to obtain a refined skeleton, then silver electrodes are coated, a cap is set, and finally, leads are connected to the cap. After encapsulation, a metal oxide ceramic resistor is obtained.

[0041] 3. Since the adhesive includes polyvinyl alcohol-sodium alginate composite hydrogel, and the prepared polyvinyl alcohol-sodium alginate composite hydrogel has a three-dimensional porous structure, when metal oxide particles are mixed with polyvinyl alcohol-sodium alginate composite hydrogel, some of the metal oxide particles enter and distribute in the pores of the polyvinyl alcohol-sodium alginate composite hydrogel, increasing the bonding area, thereby improving the bonding strength between the skeleton materials, and making the gaps between the metal oxide particles smaller, which helps to improve the density of the skeleton and further increase the strength of the skeleton. Detailed Implementation

[0042] The present application will be further described in detail below with reference to the embodiments. Example

[0043] Example 1

[0044] In a first aspect, this embodiment discloses a metal oxide ceramic resistor, comprising a frame, caps disposed at both ends of the frame, and leads connected to the caps; the frame comprises a metal oxide, which is made of the following raw materials:

[0045] 5 kg of tin oxide;

[0046] 2 kg of nickel oxide;

[0047] 4 kg of zinc oxide;

[0048] 1 kg of the remaining metal oxides; the remaining metal oxides are iron oxide.

[0049] In this embodiment, tin oxide, nickel oxide, zinc oxide and the other metal oxides are all commercially available and are all irregular particles with a particle size of 20 μm.

[0050] Secondly, this embodiment discloses a process for preparing a metal oxide ceramic resistor, including the following steps:

[0051] S1. Oxide Awakening: According to the formula, put the raw materials into the reaction vessel and allow them to permeate each other under natural conditions for 1 day to obtain an interpenetrating mixture;

[0052] S2. Rubber mixing: Take the adhesive, which is commercially available liquid polyvinyl alcohol 400, and mix the interpenetrating mixture with the adhesive at a mass ratio of 2:1. Mix and stir at a speed of 400 r / min for 0.5 days, and then extrude to obtain rods.

[0053] S3. Sintering: After sintering the rod at 1000℃, a rough skeleton is obtained;

[0054] S4. Post-processing: The outer circumference of the rough skeleton is ground to obtain a refined skeleton; after coating the refined skeleton with silver electrodes, caps are set at both ends. The caps are made of tin-plated steel. Then, leads are connected to the caps and encapsulated with an encapsulating agent to obtain a metal oxide ceramic resistor; the encapsulating agent is an organosilicon coating, which is selected from Beijing Dechang Weiye Construction Engineering Technology Co., Ltd., and the specification is 25 kg / barrel organosilicon coating.

[0055] Example 2

[0056] The difference between this embodiment and Embodiment 1 lies in the mass of tin oxide, nickel oxide, zinc oxide, and the remaining metal oxides:

[0057] 7.5 kg of tin oxide;

[0058] 4 kg of nickel oxide;

[0059] 6.5 kg of zinc oxide;

[0060] 2 kg of the remaining metal oxides.

[0061] Example 3

[0062] The difference between this embodiment and Embodiment 1 lies in the mass of tin oxide, nickel oxide, zinc oxide, and the remaining metal oxides:

[0063] 10 kg of tin oxide;

[0064] 6 kg of nickel oxide;

[0065] 9 kg of zinc oxide;

[0066] 3 kg of the remaining metal oxides.

[0067] Example 4

[0068] The difference between this embodiment and embodiment 2 is that the other metal oxides used are different. The other metal oxides used in this embodiment are copper oxide.

[0069] Example 5

[0070] The difference between this embodiment and embodiment 2 is that the other metal oxides used are different. The other metal oxides used in this embodiment are manganese oxide.

[0071] Example 6

[0072] The difference between this embodiment and embodiment 2 is that the other metal oxides used are different. The other metal oxides in this embodiment are a mixture of iron oxide and copper oxide in a mass ratio of 1:1.

[0073] Example 7

[0074] The difference between this embodiment and embodiment 2 is that the other metal oxides used are different. The other metal oxides in this embodiment are a mixture of iron oxide, copper oxide and manganese oxide in a mass ratio of 1:1:2.

[0075] Example 8

[0076] The difference between this embodiment and Embodiment 2 lies in the different fabrication process conditions for the metal oxide ceramic resistor. The fabrication process for a metal oxide ceramic resistor in this embodiment includes the following steps:

[0077] S1. Oxide Awakening: According to the formula, put the raw materials into the reaction vessel and allow them to permeate each other under natural conditions for 1 day to obtain an interpenetrating mixture;

[0078] S2. Rubber mixing: Take the adhesive, which is commercially available liquid polyvinyl alcohol 400, and mix the interpenetrating mixture with the adhesive at a mass ratio of 4:4.5. After mixing and stirring at a speed of 400 r / min for 0.5 days, extrude to obtain rods.

[0079] S3, Sintering: After sintering the rod at 1350℃, a rough skeleton is obtained;

[0080] S4. Post-processing: The outer circumference of the rough skeleton is ground to obtain a refined skeleton; after coating the refined skeleton with silver electrodes, caps are set at both ends. The caps are made of tin-plated steel. Then, leads are connected to the caps and encapsulated with an encapsulating agent to obtain a metal oxide ceramic resistor; the encapsulating agent is an organosilicon coating, which is selected from Beijing Dechang Weiye Construction Engineering Technology Co., Ltd., and the specification is 25 kg / barrel organosilicon coating.

[0081] Example 9

[0082] The difference between this embodiment and Embodiment 2 lies in the different fabrication process conditions for the metal oxide ceramic resistor. The fabrication process for a metal oxide ceramic resistor in this embodiment includes the following steps:

[0083] S1. Oxide Awakening: According to the formula, put the raw materials into the reaction vessel and allow them to permeate each other under natural conditions for 1 day to obtain an interpenetrating mixture;

[0084] S2. Rubber mixing: Take the adhesive, which is commercially available liquid polyvinyl alcohol 400, and mix the interpenetrating mixture with the adhesive at a mass ratio of 3:4. Mix and stir at a speed of 400 r / min for 0.5 days, and then extrude to obtain rods.

[0085] S3. Sintering: After sintering the rod at 1700℃, a rough skeleton is obtained;

[0086] S4. Post-processing: The outer circumference of the rough skeleton is ground to obtain a refined skeleton; after coating the refined skeleton with silver electrodes, caps are set at both ends. The caps are made of tin-plated steel. Then, leads are connected to the caps and encapsulated with an encapsulating agent to obtain a metal oxide ceramic resistor; the encapsulating agent is an organosilicon coating, which is selected from Beijing Dechang Weiye Construction Engineering Technology Co., Ltd., and the specification is 25 kg / barrel organosilicon coating.

[0087] Example 10

[0088] The difference between this embodiment and embodiment 8 is that the interpenetration treatment time in step S1 of the preparation process of the metal oxide ceramic resistor in this embodiment is 5 days, and the rubber mixing treatment time in step S2 is 2 days.

[0089] Example 11

[0090] The difference between this embodiment and embodiment 8 is that the interpenetration treatment time in step S1 of the metal oxide ceramic resistor preparation process in this embodiment is 7 days, and the rubber mixing treatment time in step S2 is 3 days.

[0091] Example 12

[0092] The difference between this embodiment and embodiment 8 is that the interpenetration treatment time in step S1 of the metal oxide ceramic resistor preparation process in this embodiment is 9 days, and the rubber mixing treatment time in step S2 is 4 days.

[0093] Example 13

[0094] The difference between this embodiment and embodiment 12 is that no encapsulating agent is used for encapsulation in step S4 of this embodiment.

[0095] Example 14

[0096] The difference between this embodiment and Embodiment 12 is that the adhesive used in step S2 of this application is a polyvinyl alcohol-sodium alginate composite hydrogel. The preparation of the polyvinyl alcohol-sodium alginate composite hydrogel includes the following steps:

[0097] (1) Preparation of polyvinyl alcohol aqueous solution: Solid polyvinyl alcohol and water are mixed and stirred at 70°C to prepare a 5% polyvinyl alcohol aqueous solution by mass fraction; the solid polyvinyl alcohol is selected from the industrial grade solid polyvinyl alcohol of Jinan Mingrun Chemical Co., Ltd.

[0098] (2) Preparation of mixed aqueous solution: Sodium alginate powder is added to the polyvinyl alcohol aqueous solution in step S1, and mixed and stirred at 30°C to obtain mixed aqueous solution; Sodium alginate is selected from sodium alginate of Xi'an Lavia Biotechnology Co., Ltd.

[0099] (3) Preparation of crosslinking agent: Dissolve boric acid and anhydrous calcium chloride in water to prepare a 1% calcium chloride saturated boric acid solution, which is the crosslinking agent;

[0100] (4) Reaction: After the mixed aqueous solution is defoamed by ultrasound and poured into a mold to form, it is soaked in the crosslinking agent in step S3 for 24 hours to obtain the soaked body; the soaked body is subjected to 3 cycles of freezing and thawing at -20℃ and room temperature to obtain polyvinyl alcohol-sodium alginate composite hydrogel.

[0101] Example 15

[0102] The difference between this embodiment and Embodiment 14 lies in the different preparation process conditions of the polyvinyl alcohol-sodium alginate composite hydrogel. The preparation of the polyvinyl alcohol-sodium alginate composite hydrogel of this application includes the following steps:

[0103] (1) Preparation of polyvinyl alcohol aqueous solution: Solid polyvinyl alcohol and water are mixed and stirred at 90°C to prepare a polyvinyl alcohol aqueous solution with a mass fraction of 10%; the solid polyvinyl alcohol is selected from the industrial grade solid polyvinyl alcohol of Jinan Mingrun Chemical Co., Ltd.

[0104] (2) Preparation of mixed aqueous solution: Sodium alginate powder is added to the polyvinyl alcohol aqueous solution in step S1, and mixed and stirred at 50°C to obtain mixed aqueous solution; Sodium alginate is selected from sodium alginate of Xi'an Lavia Biotechnology Co., Ltd.

[0105] (3) Preparation of crosslinking agent: Dissolve boric acid and anhydrous calcium chloride in water to prepare a 1% calcium chloride saturated boric acid solution, which is the crosslinking agent;

[0106] (4) Reaction: After the mixed aqueous solution is defoamed by ultrasound and poured into a mold to form, it is soaked in the crosslinking agent in step S3 for 24 hours to obtain the soaked body; the soaked body is subjected to 3 cycles of freezing and thawing at -20℃ and room temperature to obtain polyvinyl alcohol-sodium alginate composite hydrogel.

[0107] Example 16

[0108] The difference between this embodiment and Embodiment 14 lies in the different preparation process conditions of the polyvinyl alcohol-sodium alginate composite hydrogel. The preparation of the polyvinyl alcohol-sodium alginate composite hydrogel of this application includes the following steps:

[0109] (1) Preparation of polyvinyl alcohol aqueous solution: Solid polyvinyl alcohol and water are mixed and stirred at 110°C to prepare a polyvinyl alcohol aqueous solution with a mass fraction of 15%; the solid polyvinyl alcohol is selected from the industrial grade solid polyvinyl alcohol of Jinan Mingrun Chemical Co., Ltd.

[0110] (2) Preparation of mixed aqueous solution: Sodium alginate powder is added to the polyvinyl alcohol aqueous solution in step S1, and mixed and stirred at 70°C to obtain mixed aqueous solution; Sodium alginate is selected from sodium alginate of Xi'an Lavia Biotechnology Co., Ltd.

[0111] (3) Preparation of crosslinking agent: Dissolve boric acid and anhydrous calcium chloride in water to prepare a 1% calcium chloride saturated boric acid solution, which is the crosslinking agent;

[0112] (4) Reaction: After the mixed aqueous solution is defoamed by ultrasound and poured into a mold to form, it is soaked in the crosslinking agent in step S3 for 24 hours to obtain the soaked body; the soaked body is subjected to 3 cycles of freezing and thawing at -20℃ and room temperature to obtain polyvinyl alcohol-sodium alginate composite hydrogel.

[0113] Example 17

[0114] The difference between this embodiment and Embodiment 15 is that the mass fraction of the calcium chloride saturated boric acid solution in step S3 is 3%.

[0115] Example 18

[0116] The difference between this embodiment and Embodiment 15 is that the mass fraction of the calcium chloride saturated boric acid solution in step S3 is 5%.

[0117] Example 19

[0118] The difference between this embodiment and Embodiment 17 is that the particle size of the metal oxide is 1 μm.

[0119] Example 20

[0120] The difference between this embodiment and Embodiment 17 is that the particle size of the metal oxide is 3 μm.

[0121] Example 21

[0122] The difference between this embodiment and Embodiment 17 is that the particle size of the metal oxide is 5 μm.

[0123] Example 22

[0124] The difference between this embodiment and embodiment 20 is that the metal oxide in this embodiment is spherical.

[0125] Comparative Example

[0126] Comparative Example 1

[0127] In this comparative example, barium carbonate is used instead of the metal oxide in Example 2 as the framework.

[0128] Comparative Example 2

[0129] In this comparative example, carbon powder is used instead of the metal oxide in Example 2 as the framework.

[0130] Performance testing

[0131] Detection methods

[0132] (1) The test was conducted at an ambient temperature of 22°C. The test samples were the examples and comparative examples. No energy was pre-injected before the test. During the test, a 1.2Ur power frequency voltage was continuously applied to the test samples until they were destroyed.

[0133] (2) Four 4ms square wave impulse current withstand characteristic tests were conducted on each embodiment and comparative example, and the appearance of each embodiment and comparative example was observed.

[0134] Table 1 Performance Test Table

[0135]

[0136]

[0137] Comparing Examples 1-7, the difference between Examples 1-3 lies in the ratio of raw materials for metal oxide ceramic resistors and the composition of other metal oxides. By controlling the ratio of raw materials and the selection of other metal oxides, metal oxide ceramic resistors with different requirements can be prepared.

[0138] Comparing Examples 8-9 with Example 2, the difference lies in the preparation process of the metal oxide ceramic resistor. Since Example 8 exhibits the highest energy absorption and the longest duration, its process conditions are optimal.

[0139] Comparing Examples 10-12 with Example 8, the difference between Examples 10-12 and Example 8 lies in the time of interpenetration treatment in step S1 and the time of rubber mixing treatment in step S2 of the metal oxide ceramic resistor preparation process. Since Examples 10-12 have a larger energy absorption and a longer duration, it indicates that the time of interpenetration treatment and rubber mixing treatment in this application helps the metal oxides in the skeleton raw materials to mix and combine evenly, thereby helping to obtain a uniform and stable skeleton, which is conducive to improving the comprehensive performance of the metal oxide ceramic resistor.

[0140] Comparing Examples 14-16 with Example 12, the difference lies in the adhesive used. Examples 14-16 exhibit higher energy absorption and a longer duration, indicating that the polyvinyl alcohol-sodium alginate composite hydrogel is superior. When metal oxide particles are mixed with the polyvinyl alcohol-sodium alginate composite hydrogel, some of the metal oxide particles enter and distribute within the pores of the polyvinyl alcohol-sodium alginate composite hydrogel's porous structure, increasing the bonding area and thus improving the bonding strength between the skeleton materials. Furthermore, the smaller gaps between the metal oxide particles contribute to improved skeleton density and further increase skeleton strength. Additionally, Example 15 exhibits the highest energy absorption and the longest duration, indicating that the process conditions for preparing the polyvinyl alcohol-sodium alginate composite hydrogel in Example 15 are optimal.

[0141] Comparing Examples 17-18 with Example 15, the difference between Examples 17-18 and Example 15 lies in the different mass fractions of the calcium chloride saturated boric acid solution in step S3. Since Example 17 has the highest energy absorption and the longest duration, it indicates that when the mass fraction of the calcium chloride saturated boric acid solution is 3%, it helps to control the pore size of the three-dimensional porous structure within the range of 10-30 μm, which facilitates the entry and bonding of metal oxides.

[0142] Comparing Examples 19-21 with Example 17, the difference between Examples 19-21 and Example 17 lies in the particle size of the metal oxide. Since Examples 19-21 have a larger absorption energy and a longer duration, it indicates that a particle size of 1-5 μm for the metal oxide is better.

[0143] Comparing Example 22 with Example 20, the difference between Example 22 and Example 20 is that the metal oxide in Example 22 is spherical. Since Example 22 has a larger energy absorption and a longer duration, it indicates that the spherical metal oxide has good rolling and fluidity, which further facilitates the metal oxide to enter and distribute in the pores of the polyvinyl alcohol-sodium alginate composite hydrogel porous structure.

[0144] Finally, Comparative Examples 1-2 and Example 2 will be compared. The difference between Comparative Examples 1-2 and Example 2 lies in the different components of the skeleton. Since Example 2 absorbs more energy and for a longer duration, it indicates that the solution of this application is superior.

[0145] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A metal oxide ceramic resistor, characterized in that: It includes a skeleton, caps at both ends of the skeleton, and leads connected to the caps; the skeleton comprises a metal oxide, which contains the following raw materials in parts by weight: 5-10 parts of tin oxide; 2-6 parts nickel oxide; 4-9 parts zinc oxide; 1-3 parts of other metal oxides; the other metal oxides include one or more of iron oxide, copper oxide and manganese oxide; The fabrication process of the metal oxide ceramic resistor includes the following steps: S1. Oxide Awakening: According to the formula, put the raw materials into the reaction vessel and allow them to permeate each other under natural conditions to obtain an interpenetrating mixture; S2. Rubber compounding: Take the adhesive and mix the interpenetrating mixture with the adhesive at a mass ratio of 2-6:1-8. After rubber compounding, extrude to obtain rods. S3. Sintering: After sintering the rod at 1000-1700℃, a rough skeleton is obtained; S4. Post-processing: The outer diameter of the rough skeleton is ground to obtain the refined skeleton; after coating the refined skeleton with silver electrodes, caps are set at both ends, and then leads are connected to the caps. After encapsulation with encapsulating agent, metal oxide ceramic resistor is obtained. The adhesive mentioned in step S2 includes polyvinyl alcohol-sodium alginate composite hydrogel or liquid polyvinyl alcohol; The method for preparing the polyvinyl alcohol includes the following steps: (1) Preparation of polyvinyl alcohol aqueous solution: Mix solid polyvinyl alcohol and water at 70-110℃ to prepare a polyvinyl alcohol aqueous solution with a mass fraction of 5%-15%; (2) Preparation of mixed aqueous solution: Add sodium alginate powder to the polyvinyl alcohol aqueous solution in step (1), mix and stir at 30-70℃ to obtain mixed aqueous solution; (3) Preparation of crosslinking agent: Dissolve boric acid and anhydrous calcium chloride in water to prepare a calcium chloride saturated boric acid solution with a mass fraction of 1%-5%, which is the crosslinking agent; (4) Reaction: After the mixed aqueous solution is defoamed by ultrasound and poured into a mold for molding, it is immersed in the crosslinking agent in step (3) to obtain the immersed body; the immersed body is subjected to cyclic freezing and thawing treatment to obtain polyvinyl alcohol-sodium alginate composite hydrogel.

2. The metal oxide ceramic resistor according to claim 1, characterized in that: The mutual penetration treatment in step S1 takes 5-9 days, and the rubber compounding treatment in step S2 takes 2-4 days.

3. The metal oxide ceramic resistor according to claim 1, characterized in that: The encapsulating agent mentioned in step S4 is an organosilicon coating.

4. A metal oxide ceramic resistor according to claim 1, characterized in that: The particle size of the metal oxide is 1-5 μm, and the mass fraction of the calcium chloride saturated boric acid solution in step (3) is 3%.

5. A metal oxide ceramic resistor according to claim 4, characterized in that: The metal oxide is spherical.

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