NTC thermosensitive ceramic material with low resistance and high bending strength and preparation method thereof

Abstract

The application discloses an NTC thermosensitive ceramic material with low resistance and high bending strength, and relates to the technical field of thermosensitive ceramic materials. The application discloses an NTC thermosensitive ceramic material with low resistance and high bending strength, and relates to the technical field of thermosensitive ceramic materials. x Ni 0.60 Mn 2.40‑x‑y‑z‑w Mg y Bi z Ca w O4, wherein, 0

Description

Technical Field

[0001] This invention relates to the technical field of thermistor ceramic materials, and in particular to an NTC thermistor ceramic material with low resistance and high flexural strength and its preparation method. Background Technology

[0002] NTC (Negative Temperature Coefficient) thermistor ceramic materials are generally composed of two or more transition metal oxides such as Mn, Co, Ni, Al, Fe, and Cu. They are synthesized at high temperatures and have a spinel structure. They are materials with the characteristic that the resistance decreases as the temperature increases. These ceramic materials have many advantages such as fast temperature response, high power, strong surge current suppression capability, long life, high reliability, and small size. They are widely used in surge current suppression, temperature measurement, and temperature compensation.

[0003] NTC thermistor ceramic materials are typically composite oxides with an AB2O4 spinel structure composed of transition metals. For spinel-structured NTC thermistors, adding Cu is used to effectively reduce the resistivity and Brønsted (B) value, especially for materials with extremely low resistivity and high B. However, Cu-containing systems have poor stability. Due to Cu's volatile valence, aging problems are inevitable, as are the low strength and easy breakage of low-resistivity ceramic materials during use. This significantly limits the application of low-resistivity NTC thermistor ceramic resistors in high-end fields such as demanding switching power supplies, precision temperature control, and temperature measurement.

[0004] Therefore, how to prepare an NTC thermistor ceramic material with both good flexural strength and low resistivity is crucial for the thermistor component industry. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an NTC thermistor ceramic material with low resistivity and high flexural strength, as well as a method for its preparation. The NTC thermistor ceramic material of this invention features extremely low resistivity, good flexural strength, and significantly improved stability of the resistivity and flexural strength (ρ and B values). Thermistor devices prepared using this material exhibit advantages such as high stability, high reliability, and long lifespan, and have significant practical value for the industrial production of high-performance thermistor devices.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides an NTC thermistor ceramic material with low resistivity and high flexural strength, wherein the elemental composition of the NTC thermistor ceramic material is Cu. x Ni 0.60 Mn 2.40-x-y-z-w Mg yBi z Ca w O4, where 0 <x≤0.9,0<y≤0.35,0<z≤0.15,0<w≤0.3。

[0008] This invention prepares spinel-structured NTC thermistor ceramic materials with low resistivity and good flexural strength by adding MgO, Bi2O3 and CaO to NTC thermistor ceramic materials.

[0009] Preferably, the values ​​are 0.3≤x≤0.8, 0.10≤y≤0.35, 0.03≤z≤0.15, and 0.03≤w≤0.30.

[0010] Preferably, the NTC thermistor ceramic material is prepared by adding MgO, Bi2O3 and CaO to a Cu-Ni-Mn ternary system.

[0011] Secondly, the present invention also provides a method for preparing an NTC thermistor ceramic material, comprising the following steps:

[0012] (1) Weigh the six oxides Mn3O4, NiO, CuO, MgO, Bi2O3, and CaO according to the following molar ratio: Cu x Ni 0.60 Mn 2.40-x-y-z-w Mg y Bi z Ca w O4, where 0 <x≤0.9,0<y≤0.35,0<z≤0.15,0<w≤0.3;

[0013] (2) Place the weighed material, zirconium balls, and deionized water from step (1) into a ball mill jar for ball milling, and then dry the slurry after ball milling in an oven. After drying, pass the material through a sieve.

[0014] (3) Granulate the powder obtained in step (2);

[0015] (4) The powder from step (3) is dry-pressed into shape, and after debinding and high-temperature sintering, a ceramic body is obtained;

[0016] (5) Polish the ceramic body obtained in step (4) and coat both sides with silver paste as electrodes to obtain NTC thermistor ceramic material.

[0017] Preferably, in step (2), the ball milling speed is 300-500 rpm and the ball milling time is 3-6 hours.

[0018] Preferably, in step (2), the mass ratio of the material, zirconium balls, and deionized water is 1:(3-5):1.5.

[0019] Preferably, in step (2), the ball-milled slurry is poured out and dried at 80-95°C for 18-25 hours.

[0020] Preferably, in step (2), the dried material is passed through a 100-120 mesh sieve.

[0021] Preferably, the sintering temperature in step (4) is 1000-1200℃ and the sintering time is 2-3 hours.

[0022] Preferably, the silver firing conditions in step (5) are as follows: after the room temperature is raised to 100-120°C in 25-30 minutes, it is kept at that temperature for 10-12 minutes, then raised to 320-350°C in 55-60 minutes and kept at that temperature for 8-10 minutes, and then raised to 650-660°C in 55-60 minutes and kept at that temperature for 30-35 minutes.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention employs a composite material system of manganese-nickel-copper and MgO, Bi2O3, and CaO. By changing the values ​​of x, y, z, and w, the material's B value can be controlled while achieving extremely low resistivity, ensuring good flexural strength of the ceramic body. Furthermore, under long-term aging at 150℃, the change rate of both ρ and B values ​​is less than 1.3%. Compared with existing NTC thermistor ceramic materials, the material system provided by this invention features extremely low ρ, good flexural strength, and significantly improved stability of ρ and B values. Thermistor components prepared using this material have advantages such as high stability, high reliability, and long lifespan, and have significant practical value for the industrial production of high-performance thermistor components. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the preparation process of the NTC thermistor ceramic material of this invention. Detailed Implementation

[0026] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments, but the scope of protection and implementation of the present invention are not limited thereto.

[0027] Unless otherwise specified, the materials and reagents used in the following examples are commercially available.

[0028] The raw materials and specifications used in the embodiments of the present invention are shown in Table 1.

[0029] Table 1

[0030]

[0031] Example 1

[0032] A method for preparing an NTC thermistor ceramic material includes the following steps:

[0033] (1) Ingredient preparation, ball milling, and drying

[0034] According to Cu 0.7 Ni 0.60 Mn 1.36 Mg 0.15 Bi 0.09 Ca 0.10 The raw materials, zirconium balls, and deionized water were mixed according to the O4 ratio. The weighed raw materials, zirconium balls, and deionized water were placed in a ball mill jar at a weight ratio of 1:3:1.5 and ball milled for 6 hours at a speed of 300 rpm using a planetary ball mill. After ball milling, the slurry was poured out and placed in an oven to be dried at a constant temperature of 90℃ for 20 hours. The dried material was then passed through a 100-mesh stainless steel sieve.

[0035] (2) Granulation

[0036] After sieving, a 6 wt.% polyvinyl alcohol (PVA) aqueous solution binder is added to the powder, and the mixture is ground and granulated in a mortar. The granules are then passed through 60-mesh and 100-mesh sieves to select the granules in the middle layer.

[0037] (3) Dry pressing

[0038] The pellets prepared in step (2) are loaded into a steel mold and dry-pressed on a hydraulic press into cylindrical green sheets with a diameter of Φ16.00mm × 2.20mm at a pressure of 400MPa·m. -2 (Pressure calculated based on the area of ​​the pressure column).

[0039] (4) Debinding and sintering process

[0040] The green body formed in step (3) is placed in a box-type resistance furnace. After 232 minutes, the temperature is raised from room temperature to 350°C and held for 2 hours for debinding. Then, after 5 hours, the temperature is raised to 1180°C and held for 3 hours. The green body is cooled with the furnace to obtain a dense ceramic body.

[0041] (5) Silver coating

[0042] After the ceramic body sintered in step (4) is polished, silver paste is coated on both sides as electrodes. The silver firing process is as follows: the temperature is raised to 120°C in 30 minutes at room temperature (25°C), held for 10 minutes, then raised to 350°C in 60 minutes and held for 10 minutes, then raised to 650°C in 60 minutes and held for 30 minutes. The material is then cooled in the furnace to obtain the NTC thermistor ceramic material.

[0043] (6) Test

[0044] ρ25 test: Based on the R25 resistance value of the chip after silver coating, the resistivity ρ of the ceramic sheet is calculated in combination with the size of the ceramic sheet; flexural strength test: The strength of the sintered ceramic sheet is tested using the Shanghai Qingji QJWE-2000 flexural strength tester; B25 / 85 test: The resistance at 25℃ and 85℃ is tested respectively, and the B value is calculated; Aging treatment of the test sample: 150℃ is kept for 50 hours, and the resistance at 25℃ and 85℃ after aging is tested respectively. The B value after aging is calculated according to formula (a): B=1779.7×ln(R25 / R85)(a).

[0045] The test performance of the NTC thermistor ceramic material obtained in Example 1 is shown in Table 2.

[0046] Table 2 Cu 0.7 Ni 0.60 Mn 1.36 Mg 0.15 Bi 0.09 Ca 0.10 Properties of O4 ceramic materials

[0047]

[0048] As shown in Table 2, Cu 0.7 Ni 0.60 Mn 1.36 Mg 0.15 Bi 0.09 Ca 0.10 The B value of the three samples of O4 thermistor ceramic material remained at around 2630K, the resistivity was about 3.3Ω·cm, and after aging at 150℃ for 50h, the change rate of B value and resistivity was much less than 1.3%, and the flexural strength of the ceramic body was about 250N.

[0049] Example 2

[0050] A method for preparing an NTC thermistor ceramic material includes the following steps:

[0051] (1) Ingredient preparation, ball milling, and drying

[0052] According to Cu 0.4 Ni 0.60 Mn 1.20 Mg 0.35 Bi 0.15 Ca 0.3 The raw materials, zirconium balls, and deionized water were mixed according to the O4 ratio. The weighed raw materials, zirconium balls, and deionized water were placed in a ball mill jar at a weight ratio of 1:3:1 and ball milled for 3 hours at a speed of 500 rpm using a planetary ball mill. After ball milling, the slurry was poured out and placed in an oven to be dried at a constant temperature of 80℃ for 25 hours. The dried material was then passed through a 100-mesh stainless steel sieve.

[0053] (2) Granulation

[0054] Add a 6 wt.% polyvinyl alcohol (PVA) aqueous solution binder to the sieved powder, grind and mix thoroughly in a mortar to granulate, and then pass it through 60 and 100 mesh sieves to select the middle layer granules.

[0055] (3) Dry pressing

[0056] The pellets prepared in step (2) are loaded into a steel mold and dry-pressed on a hydraulic press into cylindrical green sheets with a diameter of Φ16.00mm × 2.20mm at a pressure of 400MPa·m. -2 (Pressure calculated based on the area of ​​the pressure column).

[0057] (4) Debinding and sintering process

[0058] The green body formed in step (3) is placed in a box-type resistance furnace. After 232 minutes, the temperature is raised from room temperature to 350°C and held for 2 hours for debinding. Then, after 5 hours, the temperature is raised to 1180°C and held for 3 hours. The green body is cooled with the furnace to obtain a dense ceramic body.

[0059] (5) Silver coating

[0060] After the ceramic body sintered in step (4) is polished, silver paste is coated on both sides as electrodes. The silver firing process is as follows: the temperature is raised to 120°C in 30 minutes at room temperature (25°C), held for 10 minutes, then raised to 350°C in 60 minutes and held for 10 minutes, then raised to 660°C in 60 minutes and held for 30 minutes. The material is then cooled in the furnace to obtain the NTC thermistor ceramic material.

[0061] (6) Test

[0062] The resistance was tested at 25℃ and 85℃ respectively, and the room temperature resistivity ρ, B value and flexural strength of the ceramic body were calculated according to the method of Example 1. The test samples were subjected to aging treatment: heat treatment at 150℃ for 50 hours.

[0063] The test performance of the NTC thermistor ceramic material obtained in Example 2 is shown in Table 3.

[0064] Table 3 Cu 0.4 Ni 0.60 Mn 1.20 Mg 0.35 Bi 0.15 Ca 0.3 Properties of O4 ceramic materials

[0065]

[0066] As shown in Table 3, Cu 0.4 Ni 0.60 Mn 1.20Mg 0.35 Bi 0.15 Ca 0.3 The B value of the three O4 ceramic material samples was maintained at around 3000K, the resistivity was about 51Ω·cm, and after aging at 150℃ for 50h, the change rate of B value and resistivity R value was much less than 1.3%, and the flexural strength of the ceramic body was about 525N.

[0067] Comparative Example 1

[0068] A method for preparing an NTC thermistor ceramic material includes the following steps:

[0069] (1) Ingredient preparation, ball milling, and drying

[0070] According to Cu 1.0 Ni 0.60 Mn 1.31 Mg 0.05 Bi 0.02 Ca 0.02 The ingredients were prepared according to the O4 ratio. The weighed raw materials, zirconium balls, and deionized water were placed in a ball mill jar at a weight ratio of 1:3:1.2 and ball milled for 3 hours at a speed of 500 rpm using a planetary ball mill. After ball milling, the slurry was poured out and placed in an oven to be dried at a constant temperature of 110℃ for 18 hours. The dried material was then passed through a 100-mesh stainless steel sieve.

[0071] (2) Granulation

[0072] Add a 6 wt.% polyvinyl alcohol (PVA) aqueous solution binder to the sieved powder, grind and mix thoroughly in a mortar to granulate, and then pass it through 60 and 100 mesh sieves to select the middle layer granules.

[0073] (3) Dry pressing

[0074] The pellets prepared in step (2) are loaded into a steel mold and dry-pressed on a hydraulic press into cylindrical green sheets with a diameter of Φ16.00mm × 2.20mm at a pressure of 400MPa·m. -2 (Pressure calculated based on the area of ​​the pressure column).

[0075] (4) Debinding and sintering process

[0076] The green body formed in step (3) is placed in a box-type resistance furnace. After 232 minutes, the temperature is raised from room temperature to 350°C and held for 2 hours for debinding. Then, after 5 hours, the temperature is raised to 1200°C and held for 3 hours. The green body is cooled with the furnace to obtain a dense ceramic body.

[0077] (5) Silver coating

[0078] After the ceramic body sintered in step (5) is polished, silver paste is coated on both sides as electrodes. The silver firing process is as follows: the temperature is raised to 120°C in 30 minutes at room temperature (25±5°C), held for 10 minutes, then raised to 350°C in 60 minutes and held for 10 minutes, then raised to 650°C in 60 minutes and held for 30 minutes. The material is then cooled in the furnace to obtain the NTC thermistor ceramic material.

[0079] (6) Test

[0080] The resistance was tested at 25℃ and 85℃ respectively, and the room temperature resistivity ρ, B value and flexural strength of the ceramic body were calculated according to the method of Example 1. The test samples were subjected to aging treatment: heat treatment at 150℃ for 50 hours.

[0081] The test performance of the NTC thermistor ceramic material obtained in Comparative Example 1 is shown in Table 4.

[0082] Table 4 Cu 1.0 Ni 0.60 Mn 1.31 Mg 0.05 Bi 0.02 Ca 0.02 Properties of O4 ceramic materials

[0083]

[0084] As shown in Table 4, Cu 1.0 Ni 0.60 Mn 1.31 Mg 0.05 Bi 0.02 Ca 0.02 The B value of the three O4 ceramic material samples was maintained at around 3500K, and the resistivity was about 95Ω·cm. After aging at 150℃ for 50h, the overall change rate of B value and resistance R value was less than 1.3%, but it was worse than the results of Example 1 and Example 2, and the flexural strength of the ceramic body was less than 90N.

[0085] Comparative Example 2

[0086] A method for preparing an NTC thermistor ceramic material, differing from Example 1 in that the elemental composition of the NTC thermistor ceramic material in step (1) is Cu. 0.7 Ni 0.60 Mn 1.01 Mg 0.5 Bi 0.09 Ca 0.10 O4, where x=0.7, y=0.5, z=0.09, w=0.10, and all other values ​​are the same as in Example 1.

[0087] The test performance of the NTC thermistor ceramic material obtained in Comparative Example 2 is shown in Table 5.

[0088] Table 5 Cu 0.7 Ni 0.60 Mn 1.01 Mg 0.5 Bi 0.09 Ca 0.10 Properties of O4 ceramic materials

[0089]

[0090] As shown in Table 5, Cu 0.7 Ni 0.60 Mn 1.01 Mg 0.5 Bi 0.09 Ca 0.10 The B value of the three O4 ceramic material samples was maintained at around 3600K, and the resistivity was about 150Ω·cm. After aging at 150℃ for 50h, the change rate of both the B value and the resistance R value was greater than 1.49%, and the flexural strength of the ceramic body was about 73N. It can be seen that its resistivity is much greater than the low resistance range of 3.3~51Ω·cm of Examples 1 and 2, and the flexural strength of the ceramic body and the change rate of its B value and resistance R value are worse than the results of Examples 1 and 2.

[0091] Comparative Example 3

[0092] A method for preparing an NTC thermistor ceramic material, differing from Example 1 in that the elemental composition of the NTC thermistor ceramic material in step (1) is Cu. 0.7 Ni 0.60 Mn 1.15 Mg 0.15 Bi 0.3 Ca 0.10 O4, where x=0.7, y=0.15, z=0.3, w=0.10, and all other values ​​are the same as in Example 1.

[0093] The test performance of the NTC thermistor ceramic material obtained in Comparative Example 3 is shown in Table 6.

[0094] Table 6 Cu 0.7 Ni 0.60 Mn 1.15 Mg 0.15 Bi 0.3 Ca 0.10 Properties of O4 ceramic materials

[0095]

[0096] As shown in Table 6, Cu 0.7 Ni 0.60 Mn 1.15 Mg 0.15 Bi0.3 Ca 0.10 The B value of the three O4 ceramic material samples remained at around 3800K, and the resistivity was about 180Ω·cm. After aging at 150℃ for 50h, the change rate of both the B value and the resistance R value was greater than 1.58%, and the flexural strength of the ceramic body was about 108N. It can be seen that its resistivity is much greater than the low resistance range of 3.3~51Ω·cm of Examples 1 and 2, and the flexural strength of the ceramic body and the change rate of its B value and resistance R value are worse than the results of Examples 1 and 2.

[0097] Comparative Example 4

[0098] A method for preparing an NTC thermistor ceramic material, differing from Example 1 in that the elemental composition of the NTC thermistor ceramic material in step (1) is Cu. 0.7 Ni 0.60 Mn 0.96. Mg 0.15 Bi 0.09 Ca 0.50 O4, where x=0.7, y=0.15, z=0.09, w=0.50, and all other values ​​are the same as in Example 1.

[0099] The test performance of the NTC thermistor ceramic material obtained in Comparative Example 4 is shown in Table 7.

[0100] Table 7 Cu 0.7 Ni 0.60 Mn 0.96. Mg 0.15 Bi 0.09 Ca 0.50 Properties of O4 ceramic materials

[0101]

[0102] As shown in Table 7, Cu 0.7 Ni 0.60 Mn 0.96. Mg 0.15 Bi 0.09 Ca 0.50 The B value of the three O4 ceramic material samples was maintained at around 3200K, and the resistivity was about 80Ω·cm. After aging at 150℃ for 50h, the change rate of both the B value and the resistance R value was greater than 1.38%, and the flexural strength of the ceramic body was about 63N. It can be seen that its resistivity is much greater than the low resistance range of 3.3~51Ω·cm of Examples 1 and 2, and the flexural strength of the ceramic body and the change rate of its B value and resistance R value are worse than the results of Examples 1 and 2.

[0103] Comparative Example 5

[0104] A method for preparing an NTC thermistor ceramic material differs from Example 1 in that, in step (1), MgO is replaced by an equimolar amount of TiO2, i.e., the elemental composition of the NTC thermistor ceramic material is Cu. 0.7 Ni 0.60 Mn 1.36 Ti 0.15 Bi 0.09 Ca 0.1 0O4, where x=0.7, y=0.15, z=0.09, w=0.10, and the others are the same as in Example 1.

[0105] The test performance of the NTC thermistor ceramic material obtained in Comparative Example 5 is shown in Table 8.

[0106] Table 8 Cu 0.7 Ni 0.60 Mn 1.36 Ti 0.15 Bi 0.09 Ca 0.10 Properties of O4 ceramic materials

[0107]

[0108] As shown in Table 8, Cu 0.7 Ni 0.60 Mn 1.36 Ti 0.15 Bi 0.09 Ca 0.10 The B value of the three O4 ceramic material samples remained at around 3830 K, and the resistivity was about 250 Ω·cm. After aging at 150℃ for 50 h, the change rate of both the B value and the resistance R value was greater than 2.03%, and the flexural strength of the ceramic body was about 152 N. It can be seen that its resistivity is much greater than the low resistance range of 3.3~51 Ω·cm of Examples 1 and 2, and the flexural strength of the ceramic body and the change rate of its B value and resistance R value are almost several times worse than the results of Examples 1 and 2.

[0109] Comparative Example 6

[0110] A method for preparing an NTC thermistor ceramic material differs from Example 1 in that, in step (1), Bi2O3 is replaced with an equimolar amount of Nb2O5, meaning the elemental composition of the NTC thermistor ceramic material is Cu. 0.7 Ni 0.60 Mn 1.36 Mg 0.15 Nb 0.09 Ca 0.10 O4, where x=0.7, y=0.15, z=0.09, w=0.10, and all other values ​​are the same as in Example 1.

[0111] The test performance of the NTC thermistor ceramic material obtained in Comparative Example 6 is shown in Table 9.

[0112] Table 9 Cu 0.7 Ni 0.60 Mn 1.36 Mg 0.15 Nb 0.09 Ca 0.10 Properties of O4 ceramic materials

[0113]

[0114] As shown in Table 9, Cu 0.7 Ni 0.60 Mn 1.36 Mg 0.15 Nb 0.09 Ca 0.10 The B value of the three O4 ceramic material samples was maintained at around 3500K, and the resistivity was about 200Ω·cm. After aging at 150℃ for 50h, the change rate of both the B value and the resistance R value was greater than 1.96%, and the flexural strength of the ceramic body was about 95N. It can be seen that its resistivity is much greater than the low resistance range of 3.3~51Ω·cm of Examples 1 and 2, and the flexural strength of the ceramic body and the change rate of its B value and resistance R value are several times worse than the results of Examples 1 and 2.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An NTC thermistor ceramic material with low resistivity and high flexural strength, characterized in that, The elemental composition of the NTC thermistor ceramic material is Cu. x Ni 0.60 Mn 2.40-x-y-z-w Mg y Bi z Ca w O4, where 0.3≤x≤0.8, 0.10≤y≤0.35, 0.03≤z≤0.15, and 0.03≤w≤0.

30.

2. The NTC thermistor ceramic material as described in claim 1, characterized in that, The NTC thermistor ceramic material is prepared by adding MgO, Bi2O3 and CaO to the Cu-Ni-Mn ternary system.

3. The method for preparing the NTC thermistor ceramic material according to any one of claims 1-2, characterized in that, Includes the following steps: (1) Weigh the six oxides Mn3O4, NiO, CuO, MgO, Bi2O3, and CaO according to the following molar ratio: Cu x Ni 0.60 Mn 2.40-x-y-z-w Mg y Bi z Ca w O4, where 0.3≤x≤0.8, 0.10≤y≤0.35, 0.03≤z≤0.15, 0.03≤w≤0.30; (2) Place the weighed material, zirconium balls, and deionized water from step (1) into a ball mill jar for ball milling, and then dry the slurry after ball milling in an oven. After drying, pass the material through a sieve. (3) Granulate the powder obtained in step (2); (4) The powder from step (3) is dry-pressed into shape, and after debinding and high-temperature sintering, a ceramic body is obtained; (5) Polish the ceramic body obtained in step (4) and coat both sides with silver paste as electrodes to obtain NTC thermistor ceramic material.

4. The method for preparing NTC thermistor ceramic material as described in claim 3, characterized in that, In step (2), the ball milling speed is 300-500 rpm and the ball milling time is 3-6 hours.

5. The method for preparing the NTC thermistor ceramic material as described in claim 3, characterized in that, In step (2), the mass ratio of the material, zirconium balls, and deionized water is 1:(3-5):1.

5.

6. The method for preparing the NTC thermistor ceramic material as described in claim 3, characterized in that, In step (2), the ball-milled slurry is poured out and dried at 80-95℃ for 18-25 hours.

7. The method for preparing NTC thermistor ceramic material as described in claim 3, characterized in that, In step (2), the dried material is passed through a 100-120 mesh sieve.

8. The method for preparing the NTC thermistor ceramic material as described in claim 3, characterized in that, In step (4), the sintering temperature is 1000-1200℃ and the sintering time is 2-3 hours.

9. The method for preparing the NTC thermistor ceramic material as described in claim 3, characterized in that, The conditions for silver burning in step (5) are as follows: after the room temperature is raised to 100-120℃ in 25-30 minutes, it is kept at that temperature for 10-12 minutes, then raised to 320-350℃ in 55-60 minutes and kept at that temperature for 8-10 minutes, and then raised to 650-660℃ in 55-60 minutes and kept at that temperature for 30-35 minutes.

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