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A kind of preparation method of silicon nitride, silicon carbide combined with lanthanum hexaboride foam ceramics

A technology of lanthanum hexaboride and foam ceramics, which is applied in the field of porous ceramic preparation, can solve the problems of poor thermal shock resistance, inability to meet the needs of continuous casting of large special steel castings, and low service temperature, and achieve excellent thermal shock resistance , light weight, and increased strength

Inactive Publication Date: 2016-04-20
SHANDONG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The currently used alumina foam ceramics and lanthanum hexaboride foam ceramics generally have problems such as low operating temperature and poor thermal shock resistance, which cannot meet the needs of continuous casting of large special steel castings.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0010] LaB 6 , silicon micropowder, and phenolic resin are mixed uniformly with a weight ratio of 40:40:20 and an additional concentration of 0.1wt% hydroxypropyl methylcellulose solution 40wt% to make a ceramic slurry, and then the ceramic slurry is impregnated in polyurethane On the foam, after drying, in a nitrogen atmosphere, slowly heat up at a temperature of 300 ° C ~ 1450 ° C for 20 hours, at a temperature of 1450 ° C for 5 hours, and then in a vacuum or argon atmosphere, at a temperature of 1700 ° C for 20 minutes to make nitriding Silicon, silicon carbide combined with lanthanum hexaboride foam ceramics.

[0011] The purity of the batching raw materials used in the experiment is industrial pure.

Embodiment 2

[0013] LaB 6 , silicon micropowder, and phenolic resin are mixed uniformly with a weight ratio of 60:25:15 and an additional concentration of 0.2wt% hydroxypropyl methylcellulose solution 50wt% to make a ceramic slurry, and then the ceramic slurry is impregnated in polyurethane On the foam, after drying, slowly heat up for 60 hours at a temperature of 300 ℃ ~ 1450 ℃ in a nitrogen atmosphere, keep it at 1450 ℃ for 8 hours, and then hold it at a temperature of 1730 ℃ for 70 minutes in a vacuum or argon atmosphere to make nitriding Silicon, silicon carbide combined with lanthanum hexaboride foam ceramics.

[0014] The purity of the batching raw materials used in the experiment is industrial pure.

Embodiment 3

[0016] LaB 6 , silicon micropowder, and phenolic resin are mixed uniformly with a weight ratio of 88:10:2 and an additional concentration of 0.3wt% hydroxypropyl methylcellulose solution 60wt% to make a ceramic slurry, and then the ceramic slurry is impregnated in polyurethane On the foam, after drying, slowly heat up for 100 hours at a temperature of 300 ° C ~ 1450 ° C in a nitrogen atmosphere, keep it at 1450 ° C for 10 hours, and then heat it in a vacuum or argon atmosphere at a temperature of 1750 ° C for 120 minutes to make silicon nitride. , Silicon carbide combined with lanthanum hexaboride foam ceramics.

[0017] The purity of the batching raw materials used in the experiment is industrial pure.

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PUM

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Abstract

A method for preparing silicon nitride, silicon carbide and lanthanum hexaboride foam ceramics, characterized in that: LaB6, silicon micropowder, phenolic resin and hydroxypropyl methylcellulose solution are uniformly mixed to form a ceramic slurry, and then The ceramic slurry is impregnated on the polyurethane foam, and after drying, it is fired in a nitrogen atmosphere to form silicon nitride, silicon carbide and lanthanum hexaboride foam ceramics. The silicon nitride, silicon carbide and lanthanum hexaboride foam ceramics prepared by the present invention have uniform microstructure, high strength, and uniform pore size, avoiding the residue of carbon and free silicon, and improving the strength, high temperature resistance, and thermal shock resistance. increase in magnitude.

Description

technical field [0001] The invention relates to silicon nitride, silicon carbide combined with lanthanum hexaboride foam ceramics, belonging to the technical field of porous ceramic preparation. Background technique [0002] Silicon nitride, silicon carbide combined with lanthanum hexaboride composite ceramic is a structural ceramic material with low expansion, corrosion resistance, high strength and high temperature resistance. Silicon nitride, silicon carbide and lanthanum hexaboride foam ceramics are mainly used as molten steel filter elements in steel casting and other industries for large special steel castings. The currently used alumina foam ceramics and lanthanum hexaboride foam ceramics generally have problems such as low operating temperature and poor thermal shock resistance, which can no longer meet the needs of continuous casting of large special steel castings. Contents of the invention [0003] The object of the present invention is to provide a kind of pre...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C04B38/00C04B35/50C04B35/58C04B35/565C04B35/584C04B35/622
Inventor 唐竹兴
Owner SHANDONG UNIV OF TECH