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Preparation method of porous silicon nitride ceramic material

A technology of silicon nitride ceramics and silicon nitride powder, which is applied in the direction of ceramic products, other household appliances, household appliances, etc., can solve the problems of increased production cost, high sintering temperature, and high production cost, so as to increase the porosity rate and reduce the Effect of sintering temperature and reduction of grain boundary oxide content

Active Publication Date: 2021-01-15
扬州爱斯派电器有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that the carbothermal reduction method requires a small amount of silicon nitride as a seed crystal, which increases the production cost to a certain extent. Due to the 44% weight loss in the reaction, the product has a large shrinkage during the sintering process, which is very demanding for the production shape components. unfavorable
[0004] In summary, the porous silicon nitride ceramic materials prepared by existing methods have some defects, some of which have poor corrosion resistance and heat resistance due to the presence of unreacted silicon powder in the product, and some products have low flexural strength , some have the defects of high sintering temperature, complicated preparation process and high production cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] The preparation method of modified titanium dioxide comprises the following steps:

[0023] 1) Dissolve titanium dioxide and hydroxymethyl cellulose in ethanol, then heat to 40°C and mix evenly to obtain a mixed liquid;

[0024] 2) Add straw powder to the mixed liquid in step 1), stir and mix, dry, then roast at 650°C for 3 hours under nitrogen atmosphere, cool to room temperature, and grind. The mass ratio of titanium dioxide to the hydroxymethyl cellulose is 1:0.03, and the mass ratio of the titanium dioxide to the straw powder is 1:0.1.

Embodiment 2

[0026] The preparation method of modified titanium dioxide comprises the following steps:

[0027] 1) Dissolve titanium dioxide and hydroxymethylcellulose in butanediol, then heat to 50°C and stir to mix evenly to obtain a mixed liquid;

[0028] 2) Add straw powder to the mixed liquid in step 1), stir and mix, dry, then roast at 450°C for 5h under nitrogen atmosphere, cool to room temperature, and grind. The mass ratio of the titanium dioxide to the hydroxymethyl cellulose is 1:0.06, and the mass ratio of the titanium dioxide to the straw powder is 1:0.3.

Embodiment 3

[0030] A preparation method of a porous silicon nitride ceramic material, comprising the following steps:

[0031] 1) Calculated according to weight percentage, weigh 85% of silicon nitride powder with a particle size of 0.1-10 μm, 10% of modified titanium dioxide and 5% of nano-magnesia in Example 1, and mix them uniformly to obtain a mixture;

[0032] 2) Add the mixture in step 1) to a polyethylene glycol solution with a mass concentration of 8%, and use zirconia ceramic balls for ball milling. The ball-to-material ratio is 4:1, and the ball milling time is 20 hours. The slurry is dried and passed sieve, then compression molded into blanks;

[0033] 3) Rapidly raise the temperature of the blank to 1100°C in a nitrogen atmosphere, then slowly raise the temperature to 1400°C, then raise the temperature to 1580°C at a heating rate of 1°C / min, keep it warm for 6 hours, and flow nitrogen throughout the sintering process. Finally, the porous silicon nitride ceramic material is ob...

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PUM

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Abstract

The invention brings forward a preparation method of a porous silicon nitride ceramic material, comprising the following steps: 1) weighing 60-90 wt% of silicon nitride powder, 1-20 wt% of modified titanium dioxide and 2-6 wt% of nanometer magnesia, and uniformly mixing to obtain a mixture; 2) adding the mixture obtained in the step 1) into a polyethylene glycol solution with the mass concentration of 0.5-10%, ball-milling for 2-24 h, drying slurry and sieving, and carrying out compression molding to obtain a blank; 3) rapidly heating the blank at the nitrogen atmosphere to 1100 DEG C, then heating at slow speed to 1400 DEG C, heating at the heating rate of 1 DEG C / min to 1500-1650 DEG C, carrying out heat insulation for 1-10 h, introducing flowing nitrogen during the sintering process, and finally cooling in the furnace. The modified titanium dioxide is mainly prepared from titanium dioxide, straw powder and hydroxymethyl cellulose. By the preparation method, sintering temperature islow, and the prepared porous silicon nitride ceramic material has high porosity and high fracture toughness.

Description

technical field [0001] The invention belongs to the technical field of ceramic preparation, and in particular relates to a preparation method of a porous silicon nitride ceramic material. Background technique [0002] Porous ceramics generally have the characteristics of light weight, heat insulation, heat resistance, and corrosion resistance, and are widely used in fields such as filtration, catalysis, sound absorption, gas sensing, and artificial bones. Compared with oxide-based porous ceramics, porous Si 3 N 4 Ceramics have high strength, low and stable dielectric constant, and have application prospects as a new type of "structure-function" integrated material in the military electronics industry, which has attracted extensive research. [0003] According to the different starting powders used, the existing preparation methods of porous silicon nitride ceramic materials are as follows: non-full-dense sintering method to prepare porous Si 3 N 4 Ceramics are usually α-...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B35/596C04B35/622C04B35/64C04B38/00
CPCC04B35/587C04B35/622C04B35/64C04B38/00C04B2235/3206C04B2235/3232C04B2235/5436C04B2235/5445C04B2235/6562C04B2235/6567C04B2235/658C04B2235/96C04B38/0074
Inventor 章波郭元
Owner 扬州爱斯派电器有限公司