Preparation method of precision SiC ceramic formed by gel casting based on silicone mold and precision SiC ceramic

A gel injection molding and mold technology, applied in the field of ceramic materials, can solve the problems of high rigidity and high cost of mold making, and achieve the effects of low shrinkage, simple and easy molding, and good simulation.

Active Publication Date: 2017-05-31
SOUTH CHINA INST OF COLLABORATIVE INNOVATION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The existing SiC gel injection molding process mostly uses m...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0061] A preparation method of precision SiC ceramics based on silica gel mold gel injection molding, comprising the following steps, in parts by weight:

[0062] (1) Mold production:

[0063] The RTV-4234-T4 type silica gel used has a mold-opening shrinkage a of about 3%, the empirical value of the freeze-drying linear shrinkage b of the green body is 2%, and the reaction-sintered green body linear shrinkage c is 1%. The relationship between the size M of the mold type and the size P of the final product is:

[0064] M=P / ((1-0.03)(1-0.02)(1-0.01))

[0065] According to the enlarged size, the steel mold is made by CNC, and the surface of the mold is ground and polished;

[0066] (2) Silicone mold making:

[0067] Weigh the silicone rubber and the cross-linking agent in a mass ratio of 10:1. The mixed silica gel is stirred and degassed in a vacuum injection molding machine and then poured into a container with mold seeds. After standing at room temperature for 12 hours, the ...

Embodiment 2

[0077] A preparation method of precision SiC ceramics based on silica gel mold gel injection molding, comprising the following steps, in parts by weight:

[0078] (1) Mold production:

[0079] The used RTV-4234-T4 silica gel has a mold-opening shrinkage a of 3%, the empirical value of the freeze-drying linear shrinkage b of the green body is 1.8%, and the reaction-sintered green body linear shrinkage c is 0.8%. The relationship between the size M of the mold type and the size P of the final product is:

[0080] M=P / ((1-0.03)(1-0.018)(1-0.008))

[0081] According to the enlarged size, the steel mold is made by CNC process, and the surface of the mold is ground and polished;

[0082] (2) Silicone mold making:

[0083] Weigh the silicone rubber and the cross-linking agent at a ratio of 8:1. The mixed silica gel is stirred in a vacuum injection molding machine, degassed in a vacuum, and then poured into a container with mold seeds. After standing at room temperature for 12 hour...

Embodiment 3

[0093] A preparation method of precision SiC ceramics based on silica gel mold gel injection molding, comprising the following steps, in parts by weight:

[0094] (1) Mold production:

[0095] The used RTV-4234-T4 silica gel has a mold-opening shrinkage a of about 3%, a green body freeze-drying linear shrinkage b of 1.5%, and a reaction sintered green body linear shrinkage c of 0.5%. The relationship between the size M of the mold type and the size P of the final product is:

[0096] M=P / ((1-0.03)(1-0.015)(1-0.005))

[0097] According to the enlarged size of the CNC process, the steel mold is made, and the surface of the mold is ground and polished;

[0098] (2) Silicone mold making:

[0099] Weigh the silicone rubber and the cross-linking agent at a ratio of 5:1. The mixed silica gel is stirred and degassed in a vacuum injection molding machine, and then poured into a container with mold seeds. After standing at room temperature for 12 hours, the silica gel is cured. Cut th...

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PUM

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Abstract

The invention belongs to the technical field of ceramic materials and discloses a preparation method of precision SiC ceramic formed by gel casting based on a silicone mold and the precision SiC ceramic. The preparation method disclosed by the invention comprises the following steps: firstly, producing a mold seed: determining the size M of the mold seed according to a formula M=P/((1-a)(1-b)(1-c)); carrying out three-dimensional molding, producing the mold seed and carrying grinding and polishing treatment on the surface of the mold seed; secondly, producing the silicone die; thirdly, preparing ceramic slurry; fourthly, carrying out gel casting; fifthly, carrying out drying treatment on a green body; sixthly, carrying out sintering treatment to obtain a SiC ceramic part. The invention also discloses the precision SiC ceramic prepared by the method. According to the method, the gel casting, freeze drying and reaction sintering are carried out by using the silicone mold with good elasticity, the technical difficult problems of difficulty in deformation and easiness in deformation of the ceramic part with a complex structure are solved, and the preparation of the SiC ceramic with the complex structure and precision dimension is realized.

Description

technical field [0001] The invention belongs to the technical field of ceramic materials, and in particular relates to a preparation method of precision SiC ceramics based on silica gel mold gel injection molding and the precision SiC ceramics. Background technique [0002] SiC ceramics are a class of structural ceramics with excellent properties. SiC ceramics have become the most promising structural ceramics due to their outstanding advantages such as high hardness, high temperature strength, strong oxidation resistance, good wear resistance, small thermal expansion coefficient, high thermal conductivity, thermal shock resistance and chemical corrosion resistance. One of them, it has been widely used in metallurgy, machinery, petroleum, chemical industry, microelectronics, aerospace, steel, automobile and other fields, and is often used as precision bearings, seals, steam turbine rotors, nozzles, combustion chambers, heat exchangers, optical satellites Lightweight reflect...

Claims

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Application Information

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IPC IPC(8): C04B35/565C04B35/573C04B35/632C04B35/634B28B7/34
Inventor 郑华德艾树鹤张明
Owner SOUTH CHINA INST OF COLLABORATIVE INNOVATION
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