Method for preparing high-temperature NTC heat-sensitive resistance material

A thermistor and high temperature technology, applied in the direction of resistors with negative temperature coefficients, etc., can solve problems such as weak research

Inactive Publication Date: 2009-11-25
XI AN JIAOTONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

At present, the research on room temperature thermistor materials is very mature, but the research o

Method used

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  • Method for preparing high-temperature NTC heat-sensitive resistance material
  • Method for preparing high-temperature NTC heat-sensitive resistance material
  • Method for preparing high-temperature NTC heat-sensitive resistance material

Examples

Experimental program
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Effect test

Embodiment 1

[0017] Embodiment 1, 1) at first, press FeNi 0.5 mn 1.5 o 4 The chemical formula will analyze pure Fe 2 o 3 , NiO, MnO 2 and Cr 2 o 3 Put the powder into a plastic tank, and add ethanol: FeNi to the plastic tank 0.5 mn 1.5 o 4 , adding ethanol at a volume ratio of 1:1, and then using agate balls as the grinding medium, ball milling on a high-speed ball mill for 4 hours to obtain the mixture;

[0018] 2) Then, the mixture was dried in an oven at 75° C. for 12 hours and then ground through a 200-mesh sieve, then adding 4% of the mixture mass concentration to it was 5% PVA binder, and pressed it under a pressure of 100 MPa into a disc with a diameter of 10mm and a height of 2mm;

[0019] 3) Finally, put the pressed disc into a high-temperature sintering furnace for sintering. The sintering temperature control program is: (1) Low-temperature stage: from room temperature to 300°C at a heating rate of 75°C / h, and then to 300°C Keep warm for 2 hours; (2) Decomposition and ...

Embodiment 2

[0020] Embodiment 2, 1) at first, press Fe 0.99 Ni 0.5 mn 1.5 Cr 0.01 o 4 The chemical formula will analyze pure Fe 2 o 3 , NiO, MnO 2 and Cr 2 o 3 Put the powder into a plastic tank, and add ethanol: Fe 0.99 Ni 0.5 mn 1.5 Cr 0.01 o 4 Add ethanol at a volume ratio of 1:1, then use agate balls as the grinding medium, and ball mill on a high-speed ball mill for 4 hours to obtain the mixture;

[0021] 2) Then, the mixture is dried in an oven at 75° C. for 12 hours and then ground through a 200-mesh sieve, then adding 2% of the mixture mass concentration to it is 5% PVA binder, and pressing it under a pressure of 100 MPa into a disc with a diameter of 10mm and a height of 2mm;

[0022] 3) Finally, put the pressed disc into a high-temperature sintering furnace for sintering. The sintering temperature control program is: (1) Low-temperature stage: from room temperature to 300°C at a heating rate of 75°C / h, and then to 300°C Keep warm for 2 hours; (2) Decomposition and...

Embodiment 3

[0023] Embodiment 3, 1) at first, press Fe 0.96 Ni 0.5 mn 1.5 Cr 0.04 o 4 The chemical formula will analyze pure Fe 2 o 3 , NiO, MnO 2 and Cr 2 o 3 Put the powder into a plastic tank, and add ethanol: Fe 0.96 Ni 0.5 mn 1.5 Cr 0.04 o 4 Add ethanol at a volume ratio of 1:1, then use agate balls as the grinding medium, and ball mill on a high-speed ball mill for 4 hours to obtain a mixture;

[0024] 2) Then, the mixture is dried in an oven at 75° C. for 12 hours and then ground through a 200-mesh sieve, then adding 5% of the mixture mass concentration is 5% PVA binder, and pressing it under a pressure of 100 MPa into a disc with a diameter of 10mm and a height of 2mm;

[0025] 3) Finally, put the pressed disc into a high-temperature sintering furnace for sintering. The sintering temperature control program is: (1) Low-temperature stage: from room temperature to 300°C at a heating rate of 75°C / h, and then to 300°C Keep warm for 2 hours; (2) Decomposition and oxidati...

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Abstract

The invention discloses a method for preparing a high-temperature NTC heat-sensitive resistance material. Pure Fe2O3, NiO, MnO2 and Cr2O3 are selected and analyzed, then the materials are sintered according to a chemical formula mixture ratio of Fe[1-x]Ni0.5Mn1.5CrxO4 (x is selected from 0 to 0.16), the unadulterated FeNi0.5Mn1.5O4 basically meets the using requirement as the high-temperature NTC heat-sensitive resistance material, and the adulteration of Cr shows higher material constant B value of about 6,000K and room temperature resistivity change range of 10 to 10 omega/centimeter and achieves the using requirement under high-temperature conditions. The tissue structure characteristics required in the application of the high-temperature NTC material comprise that: the adulteration of little Cr2O3 does not change a phase structure of a matrix, the system with the adulteration amount in a certain range forms a single spinel phase, and no second phase appears; the grain size of the adulterated sample is comparatively even, and the grain boundary growth is comparatively perfect and has no abnormal growing grains; and a sintered sample has low porosity and enough compactness.

Description

technical field [0001] The invention relates to a preparation method of an NTC thermistor material, in particular to a preparation method of a high-temperature NTC thermistor material. Background technique [0002] Negative temperature coefficient (NTC) thermistor materials are materials whose resistance decreases as temperature increases. Due to the performance of NTC thermistor material, it is widely used in temperature measurement, temperature control and temperature compensation. [0003] The most commonly used NTC thermistor material system is a manganese-based material with a spinel structure, and the main conductive mechanism is the Mn between oxygen octahedrons. 3+ Ions and Mn 4+ Jump conductance between ions. Generally, manganese-containing heat-sensitive materials are used at room temperature, and their material constants are relatively small. Fe 2+ / Fe 3+ ,Co 2+ / Co 3+ conducting conduction. However, the general spinel system will age due to the ion excha...

Claims

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Application Information

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IPC IPC(8): C04B35/622C04B35/36H01C7/04
Inventor 乔冠军王毛领
Owner XI AN JIAOTONG UNIV
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