Preparation method of high thermal conductivity and high strength aluminum nitride ceramics

An aluminum nitride ceramic, high-strength technology, applied in the field of ceramic material preparation, can solve the problem of not being able to take into account performance at the same time, and achieve the effects of reducing the number of grain boundary phases, fine grains, and reducing scattering

Active Publication Date: 2018-11-23
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the above-mentioned inventions only unilaterally emphasize high thermal conductivity or high strength, and fail to take into account both performances at the same time. The present invention uses nano-aluminum nitride powder as a raw material to invent a kind of atmospheric pressure sintering that can prepare both high thermal conductivity and high strength. A new approach to aluminum nitride ceramics

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] 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 oxide;

[0020] 2. Powder mixing: Weigh 1000g of nano-aluminum nitride powder and 50g of yttrium oxide powder, put 0.5wt% oleic acid into a ball mill jar, add 2000g of high-purity zirconia balls, 2000ml of absolute ethanol, ball mill and mix for 12 hours before drying Sieve to obtain mixed powder;

[0021] 3. Forming and degreasing: Add 50g of rubber gasoline to the mixed powder as a binder, place it in a mold for dry pressing, and then perform thermal degreasing in an inert atmosphere to obtain a green body;

[0022] 4. Pre-sintering and final sintering: Pre-sinter the green body at a temperature of 1500°C in a nitrogen-containing reducing atmosphere at normal pressure for 4 hours, the gas flow rate is 5L / min, the volume fraction of nitrogen is 95%, the volume of ammonia is The fraction is 4%, the volume fraction of hydro...

Embodiment 2

[0025] 1. Raw material powder: The raw material is aluminum nitride powder with a primary particle size of 80 nanometers, and the sintering aid is yttrium oxide;

[0026] 2. Powder mixing: Put 1000g of nano-aluminum nitride powder, 30g of yttrium oxide powder, and 0.5wt% oleic acid into a ball mill tank, add 2000g of high-purity zirconia balls, 2000ml of absolute ethanol, mix for 12 hours, dry and sieve Obtain mixed powder;

[0027] 3. Forming and degreasing: add the mixed powder to 180g of wax-based binder to make the feed, then perform injection molding, and then get the green body after solvent degreasing and thermal degreasing;

[0028] 4. Pre-sintering and final sintering: Pre-sinter the green body at a temperature of 1400°C in a nitrogen-containing reducing atmosphere at normal pressure for 3 hours, the gas flow rate is 3L / min, the volume fraction of nitrogen is 70%, the volume of ammonia is The fraction is 20%, and the volume fraction of hydrogen cyanide is 10%. Then,...

Embodiment 3

[0031] 1. Raw material powder: the raw material is aluminum nitride powder with a primary particle size of 150 nanometers, and the sintering aid is yttrium fluoride;

[0032] 2. Powder mixing: Put 1000g of nano-aluminum nitride powder, 60g of lanthanum oxide powder, and 0.5wt% oleic acid into a ball mill tank, add 2000g of high-purity zirconia balls, 2000ml of absolute ethanol, mix for 12 hours, dry and sieve Obtain mixed powder;

[0033] 3. Forming and degreasing: add the mixed powder to 160g of paraffin wax to form a green body by hot pressing; then degrease by siphon to obtain a green body;

[0034] 4. Pre-sintering and final sintering: Pre-sinter the green body at 1300°C for 2 hours in a nitrogen-containing reducing atmosphere at normal pressure, with a gas flow rate of 4L / min, in which the volume fraction of nitrogen is 90%, and the volume fraction of ammonia is The fraction is 3%, and the volume fraction of hydrogen cyanide is 7%. Sintering was then performed at a temp...

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Abstract

The invention discloses a preparation method of high thermal conductivity and high strength aluminum nitride ceramics, belonging to the technical field of preparation of ceramic materials. According to the preparation method, aluminum nitride powder with a primary particle size less than 200nm is used as a raw material; an oxide or a halide of a rare earth metal is added as a sintering aid, and the adding amount is 1-6wt%. The method comprises the steps of mixing and molding the raw material powder, then pre-sintering for 1-5h at the temperature of 1300-1500 DEG C in a nitrogen-containing reducing atmosphere under the normal pressure, and then sintering for 3-10h at the temperature of 1500-1800 DEG C in a nitrogen atmosphere. The prepared aluminum nitride ceramics has a grain size of lessthan 3mu m, a thermal conductivity of not less than 150W/m.K, a bending strength of not less than 500MPa, and a hardness of not less than HRC 88.

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. 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 development of scie...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/581C04B35/622C04B35/626C04B35/64
CPCC04B35/581C04B35/622C04B35/62615C04B35/64C04B2235/3225C04B2235/3227C04B2235/6567C04B2235/6586C04B2235/661C04B2235/786C04B2235/96C04B2235/9607
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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