Method for preparing aluminum nitride ceramics with high heat conduction and high strength by SPS sintering

A high-strength technology for aluminum nitride ceramics, which is applied in the field of SPS sintering to prepare high thermal conductivity and high-strength aluminum nitride ceramics. It can solve the problems of small porosity and does not consider the improvement of thermal conductivity and strength of aluminum nitride ceramics. , to achieve the effects of reducing scattering, reducing the number of grain boundary phases, and inhibiting growth

Active Publication Date: 2018-10-19
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method only emphasizes the preparation of transparent aluminum nitride ceramics with small porosity and high density, without considering the improvement of thermal conductivity and strength of aluminum nitride ceramics

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] 1. Raw material powder: the raw material is aluminum nitride powder with a primary particle size of 100 nanometers, and the sintering aid is yttrium fluoride;

[0021] 2. Powder mixing: Put 1000g of aluminum nitride powder, 20g of yttrium fluoride, and 1wt% oleic acid into a ball mill tank, add 2000g of high-purity zirconia balls, 2000ml of absolute ethanol, mix for 10 hours after ball milling, dry and sieve to obtain the mixture powder;

[0022] 3. Forming and pre-sintering: press the mixed powder to obtain a green body, the pressing pressure is 80MPa, and then pre-sinter the green body at a temperature of 1500°C in a nitrogen-containing reducing atmosphere at normal pressure for 4 hours, and the gas flow rate is 2L / min , wherein the volume fraction of nitrogen is 90%, the volume fraction of ammonia is 5%, and the volume fraction of hydrogen cyanide is 5%;

[0023] 4. Final sintering: The pre-sintered billet is subjected to spark plasma sintering under the protection ...

Embodiment 2

[0026] 1. Raw material powder: the raw material is aluminum nitride powder with a primary particle size of 80 nanometers, and the sintering aid is lanthanum fluoride;

[0027] 2. Powder mixing: put 1000g of aluminum nitride powder, 30g of lanthanum fluoride, and 1wt% oleic acid into a ball mill jar, add 2000g of high-purity zirconia balls, 2000ml of absolute ethanol, mix for 10 hours after ball milling, dry and sieve to obtain the mixture powder;

[0028] 3. Forming and pre-sintering: Press the mixed powder to obtain a green body, the pressing pressure is 50MPa, and then pre-sinter the green body at a temperature of 1400°C in a nitrogen-containing reducing atmosphere for 4 hours, and the gas flow rate is 3L / min, where The volume fraction of nitrogen is 95%, the volume fraction of ammonia is 2%, and the volume fraction of hydrogen cyanide is 3%;

[0029] 4. Final sintering: The pre-sintered compact was subjected to spark plasma sintering under the protection of high-purity nit...

Embodiment 3

[0032] 1. Raw material powder: the raw material is aluminum nitride powder with a primary particle size of 60 nanometers, and the sintering aid is yttrium fluoride;

[0033] 2. Powder mixing: Put 1000g of aluminum nitride powder, 15g of yttrium fluoride, and 1wt% oleic acid into a ball mill tank, add 2000g of high-purity zirconia balls, 2000ml of absolute ethanol, mix for 10 hours after ball milling, dry and sieve to obtain the mixture powder;

[0034] 3. Forming and pre-sintering: press the mixed powder to obtain a green body, the pressing pressure is 100MPa, and then pre-sinter the green body at a temperature of 1300°C in a nitrogen-containing reducing atmosphere for 2 hours, and the gas flow rate is 3L / min, where The volume fraction of nitrogen is 80%, the volume fraction of ammonia is 10%, and the volume fraction of hydrogen cyanide is 10%;

[0035]4. Final sintering: The pre-sintered billet is subjected to spark plasma sintering under the protection of high-purity nitrog...

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Abstract

The invention discloses a method for preparing aluminum nitride ceramics with high heat conduction and high strength by SPS sintering, and belongs to the technical field of ceramic material preparation. Aluminum nitride powder with the primary particle size of less than 200 nm is used as a raw material, rare earth metal fluoride is added as a sintering aid, and the addition amount is 1 wt%-4 wt%.The raw material powder is subjected to powder mixing, formed and pre-sintered in a nitrogen-containing reducing atmosphere, and then is sintered by spark plasma under the protection of high-purity nitrogen, wherein the sintering temperature is 1500 DEG C-1700 DEG C, the heat preservation time is 1-6 min, and the axial pressure is 30-50 MPa. The aluminum nitride ceramics having grain size of lessthan 1 micron, the thermal conductivity of not less than 100 W / m.K, the bending strength of not less than 700 MPa and the hardness of not less than HRC 94 are prepared.

Description

technical field [0001] The invention belongs to the technical field of ceramic material preparation, and relates to a method for preparing aluminum nitride ceramics with high thermal conductivity and high strength by SPS sintering. Background technique [0002] AlN ceramics have a series of excellent properties such as high thermal conductivity, relatively low dielectric constant and dielectric loss, thermal expansion coefficient matching silicon and gallium arsenide and other chip materials, non-toxic, insulation, etc., and are considered to be new The first choice material for a generation of high-performance ceramic heat dissipation devices (the theoretical thermal conductivity of aluminum nitride is 320W / m K, which is about ten times that of alumina ceramics; the thermal expansion coefficient is about 3.5 to 4.8×10 -6 K -1 , 20 ~ 500 ℃), has been widely used in electronics, automobiles, aerospace, military defense and other fields. [0003] In recent years, with the de...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/581C04B35/622C04B35/626C04B35/64
CPCC04B35/581C04B35/622C04B35/62605C04B35/62645C04B35/62675C04B35/6268C04B35/64C04B2235/6562C04B2235/6567C04B2235/658C04B2235/96C04B2235/9607
Inventor 秦明礼何庆鲁慧峰吴昊阳刘昶曲选辉
Owner UNIV OF SCI & TECH BEIJING
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