Method for preparing high-strength and high-thermal-conductivity aluminum nitride through hot pressed sintering

A hot-pressing sintering, high thermal conductivity technology, applied in the field of high-strength and high-strength hot-pressing sintering, can solve the problems of reducing liquid phase, unfavorable densification, reduction and so on

Pending Publication Date: 2021-05-18
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the reduction of oxygen content reduces the liquid phase at high temperature, which is not

Method used

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  • Method for preparing high-strength and high-thermal-conductivity aluminum nitride through hot pressed sintering
  • Method for preparing high-strength and high-thermal-conductivity aluminum nitride through hot pressed sintering
  • Method for preparing high-strength and high-thermal-conductivity aluminum nitride through hot pressed sintering

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Weigh 50.00g of aluminum nitride, 1.54g of yttrium oxide, 2.79g of PVB and 200ml of alcohol into a ball mill jar, mix evenly at a speed of 70 rpm, put the suspension into a drying oven for drying, grind and sieve each Take 1.5g of the mixture and mold it into a φ15 disc. Put the pattern into a tube furnace for degreasing under nitrogen atmosphere, raise the temperature to 450°C at a rate of 5°C / min, keep it warm for 3 hours and then cool down with the furnace to obtain an aluminum nitride green body. Put the green body into a graphite crucible and raise the temperature up to 1500°C at a rate of 10°C / min, then keep it warm in flowing nitrogen for 4h for pre-sintering. Then put the pre-sintered sample into a hot-pressed graphite mold, raise the temperature to 1750 °C at a rate of 10 °C / min, and then apply a pressure of 30 MPa and keep it for 2 h. Then put it into a graphite furnace and raise it to 1800°C at 10°C / min for 5 hours, then cool it down to 1000°C at 10°C / min an...

Embodiment 2

[0026] Weigh 50.00g of aluminum nitride, 1.02g of calcium oxide, 1.61g of yttrium oxide, 2.83g of PVB and 200ml of alcohol into a ball mill jar, mix evenly at a speed of 70 rpm, and put the suspension into a drying oven for drying. After grinding and sieving, take 1.5g of the mixture each time and mold it into a φ15 disc. Put the pattern into a tube furnace for degreasing under nitrogen atmosphere, raise the temperature to 450°C at a rate of 5°C / min, keep it warm for 3 hours and then cool down with the furnace to obtain an aluminum nitride green body. Put the green body into a graphite crucible and raise the temperature to 1450°C at a rate of 10°C / min, then keep it warm in flowing nitrogen for 5h for pre-sintering. Put the green body into a hot-pressed graphite mold, raise the temperature to 1650°C at a rate of 10°C / min, and then apply a pressure of 35MPa, and then cool it down to 1000°C at 10°C / min after holding for 1 hour. Then put it into a graphite furnace at 10°C / min and...

Embodiment 3

[0028] Weigh 50.00g of aluminum nitride, 1.02g of dysprosium oxide, 1.61g of yttrium oxide, 2.83g of PVB and 200ml of alcohol into a ball mill jar, mix evenly at a speed of 70 rpm, and put the suspension into a drying oven for drying. After grinding and sieving, take 1.5g of the mixture each time and mold it into a φ15 disc. Put the pattern into a tube furnace for degreasing under nitrogen atmosphere, raise the temperature to 450°C at a rate of 5°C / min, keep it warm for 3 hours and then cool down with the furnace to obtain an aluminum nitride green body. Put the green body into a graphite crucible and raise the temperature to 1550°C at a rate of 10°C / min, and then keep it in flowing nitrogen for 3h to carry out pre-sintering. Put the green body into a hot-pressed graphite mold, raise the temperature to 1700°C at a rate of 10°C / min, then apply a pressure of 25MPa, keep it for 2.5 hours, then cool it down to 1000°C at 10°C / min, and cool in the furnace. Then put it into a graphi...

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Abstract

The invention aims to prepare an aluminum nitride ceramic material with high strength and high thermal conductivity, and belongs to the technical field of ceramic material preparation. In order to obtain the aluminum nitride ceramic with low oxygen content and fine grain structure, a novel method of pre-sintering, hot pressed sintering and high-temperature annealing is designed, wherein the pre-sintering temperature is 1400-1600 DEG C, the sintering time is 2-5 hours, the hot pressing sintering temperature is 1650-1800 DEG C, the sintering time is 0.5-3 hours, the sintering pressure is 15-45 MPa, the annealing temperature is 1750-1800 DEG C, and the annealing time is 3-8 hours. According to the method, presintering oxygen reduction and annealing deoxidation are utilized, so that the impurity oxygen content, especially the lattice oxygen content, of the aluminum nitride ceramic is effectively reduced. Therefore, under the condition of ensuring the strength, the heat conductivity of the aluminum nitride ceramic is remarkably improved, and the aluminum nitride ceramic has high practical value. The ceramic prepared by the method has the advantages of fine grains and low impurity oxygen content, the average grain size is less than 3 microns, the thermal conductivity is higher than 200W/m.k, the total oxygen content is lower than 1%, and the bending strength is higher than 350MPa.

Description

technical field [0001] The invention belongs to the technical field of ceramic material preparation technology, in particular to a hot-pressed sintered high-strength high-strength [0002] Preparation of Thermal Conductivity Aluminum Nitride Ceramics. Background technique [0003] Aluminum nitride not only has high thermal conductivity (theoretical up to 320W m -1 ·K -1 ), good insulation (>10 14 Ω cm), low dielectric constant (8.0 under 1MHz test condition) and dielectric loss (dielectric loss angle is tanδ=10 -4 ), thermal expansion coefficient matching silicon (3.2×10 -6 k -1 ), and has good chemical stability and non-toxicity, and has been widely used in semiconductors, electric vacuum and other fields, and is also a key material for electronic components in automotive electronics, aerospace, and military defense. For example, the aluminum nitride substrate is the key carrier of high-speed rail transit and new energy vehicle IGBT modules, which can effectively p...

Claims

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Application Information

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IPC IPC(8): C04B35/581C04B35/622C04B35/64C04B35/645
CPCC04B35/581C04B35/622C04B35/64C04B35/645C04B2235/3208C04B2235/3224C04B2235/3225C04B2235/5436C04B2235/658
Inventor 秦明礼张智睿刘昶吴昊阳贾宝瑞曲选辉
Owner UNIV OF SCI & TECH BEIJING
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