Environment-friendly method for preparing silicon nitride ceramic green body by gel injection molding

A technology of gel injection molding and silicon nitride ceramics, which is applied in the field of ceramic material molding and preparation, can solve the problems of green body deformation, low strength, and easy damage of the green body, and achieve high molding precision and good uniformity Effect

Inactive Publication Date: 2018-07-20
UNIV OF JINAN
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The green body prepared by the traditional colloidal molding process usually shrinks greatly during the drying process, which causes problems such as deformation and cracking of the green body during the dry

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] (1) Silicon nitride powder pretreatment: In the ball mill, add silicon nitride: 960g, scandium trioxide: 10g, soybean oil: 30g, turn on the ball mill and grind for 2 hours, dry to get the pretreated silicon nitride powder , the particle size is between 0.15~0.25μm;

[0024] (2) Gel solution preparation: In the reactor, add deionized water: 950 mL, Carbomer 941: 10g, ammonium citrate: 30g, ethylenediamine: 10g, stir and dissolve to obtain a gel solution;

[0025] (3) Preparation of silicon nitride ceramic slurry: In a ball mill, add separately, pre-treated silicon nitride powder: 500 mL, gel solution: 450 mL, ammonium oxalate: 50 g, grind for 11 hours, vacuum defoaming treatment, get Silicon nitride ceramic slurry;

[0026] (4) Preparation of silicon nitride green body: Inject the silicon nitride ceramic slurry in step (3) into the mold, heat slowly, and keep the temperature at 85±3°C for 17 hours. After natural cooling, dry and demould to obtain nitrogen Silicon biscu...

Embodiment 2

[0028] (1) Silicon nitride powder pretreatment: In the ball mill, add silicon nitride: 950g, lanthanum oxide: 20g, peanut oil: 30g, turn on the ball mill and grind for 2 hours, dry to get the pretreated silicon nitride powder, its The particle size is between 0.15~0.25μm;

[0029] (2) Gel solution preparation: In the reactor, add deionized water: 980 mL, Carbomer 941: 5g, ammonium citrate: 10g, ethylenediamine: 5g, stir and dissolve to obtain a gel solution;

[0030] (3) Preparation of silicon nitride ceramic slurry: In a ball mill, add separately, pre-treat silicon nitride powder: 480 mL, gel solution: 460 mL, ammonium oxalate: 60 g, grind for 10 hours, vacuum defoaming treatment, get Silicon nitride ceramic slurry;

[0031] (4) Preparation of silicon nitride biscuit: inject the silicon nitride ceramic slurry in step (3) into the mold, heat slowly, and keep the temperature at 85±3°C for 16 hours. After natural cooling, dry and demould to obtain nitrided Silicon blank.

Embodiment 3

[0033] (1) Silicon nitride powder pretreatment: In the ball mill, add silicon nitride: 970g, zirconium dioxide: 2g, rapeseed oil: 28g, turn on the ball mill and grind for 2 hours, dry to obtain pretreated silicon nitride powder body, its particle size is between 0.15 and 0.25 μm;

[0034] (2) Gel solution preparation: In the reactor, add deionized water: 940 mL, Carbomer 941: 20g, ammonium citrate: 20g, ethylenediamine: 20g, stir and dissolve to obtain a gel solution;

[0035] (3) Preparation of silicon nitride ceramic slurry: In a ball mill, add separately, pretreat silicon nitride powder: 530 mL, gel solution: 440 mL, ammonium oxalate: 30 g, grind for 12 hours, vacuum defoaming treatment, get Silicon nitride ceramic slurry;

[0036] (4) Preparation of silicon nitride biscuit: inject the silicon nitride ceramic slurry in step (3) into the mold, heat slowly, and keep the temperature at 85±3°C for 18 h. After natural cooling, dry and demould to obtain nitrogen Silicon biscuit...

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PUM

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Abstract

The invention discloses an environment-friendly method for preparing a silicon nitride ceramic green body by gel injection molding. The environment-friendly method is characterized by comprising the following steps: pre-treating silicon nitride powder by adopting edible oil to obtain pre-treated silicon nitride powder; taking carbomer 941 as an adhesive, ammonium citrate and ethylenediamine as acidity regulators and a dispersant to prepare a gel solution; then adding the following components into a ball grinding mill according to the volume percent: 48 percent to 53 percent of the pre-treatedsilicon nitride powder, 43 percent to 48 percent of a gel solution and 3 percent to 6 percent of ammonium oxalate, wherein the sum of all the components is 100 percent; grinding for 10 to 12h and carrying out vacuum de-foaming treatment to obtain silicon nitride ceramic slurry; injecting the silicon nitride ceramic slurry into a mold and slowly heating; heating until the temperature is 85+/-3 DEGC and keeping the constant temperature for 16 to 18h; after naturally cooling, drying and de-molding to obtain the silicon nitride green body. The silicon nitride green body prepared by the method hasthe advantages of high solid content, low organic matter content and environment protection; after sintering, the density of obtained silicon nitride ceramic is high.

Description

technical field [0001] The invention belongs to the field of molding and preparation of ceramic materials, and in particular relates to an environment-friendly gel injection molding method for preparing silicon nitride ceramic biscuits. A method for preparing dense silicon nitride ceramic products. Background technique [0002] Silicon nitride ceramic is an inorganic material ceramic that does not shrink when sintered. Silicon nitride is very strong, especially hot-pressed silicon nitride, which is one of the hardest substances in the world. It has the advantages of high strength, low density, high temperature resistance, good chemical corrosion resistance, high hardness, good wear resistance, small friction coefficient, low density, etc. It has application prospects both as structural materials and functional materials. more attention. Silicon nitride ceramics have been widely used in industrial fields such as petroleum, chemical industry, microelectronics, aerospace, av...

Claims

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Application Information

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IPC IPC(8): C04B35/584C04B35/64
CPCC04B35/584C04B35/64C04B2235/3224C04B2235/3227C04B2235/3244C04B2235/6022
Inventor 李慧芝郭方全何成贵
Owner UNIV OF JINAN
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