Silicon carbide green body and production process thereof

Abstract

The invention discloses a silicon carbide green body and a production process thereof. The green body is prepared by carrying out extrusion molding on a main material silicon carbide and auxiliary materials, wherein the auxiliary materials are powdered graphite with a gain size of 3500 meshes, hydroxypropyl methyl cellulose with a gain size of 80 meshes and powdered poval with a gain size of 160 meshes. The process is a green body forming method in which reaction-sintered silicon carbide square beam and roller rod products are changed through extrusion molding. The process has the advantages that compared with the traditional method in which a square beam green body is produced by virtue of grouting molding, in the process disclosed by the invention, the granularity of the selected raw materials is relative coarse, thus the machining process and cost of micro-powder are saved, the machining cost of the raw materials is reduced, simultaneously, the manufacturing expenditure and raw material cost of a gypsum mould are saved, the operation process is simplified, and the work efficiency is improved.

Description

technical field [0001] The invention relates to a ceramic green body, in particular to a silicon carbide green body and a production process thereof, belonging to the field of ceramic production. Background technique [0002] Silicon carbide ceramics have excellent characteristics such as high mechanical strength, high temperature resistance, strong oxidation resistance, good thermal stability, high thermal conductivity, good wear resistance, good chemical corrosion resistance, high hardness, and good thermal shock resistance. Reaction sintered silicon carbide is a new type of high-tech ceramics, widely used in metallurgy, petroleum, chemical industry, electronics, ceramics, and electric porcelain kiln furniture. The basic principle of reaction sintered silicon carbide ceramics is: reactive liquid silicon or gaseous silicon, infiltrated into a carbon-containing porous ceramic green body under capillary action, and reacts with the carbon in it to form silicon carbide, and the...

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Problems solved by technology

[0003] However, the molding of the above-mentioned product bodies is mostly done by dry pressing and grouting. For example, the patent No. CN200910014078.8 titled "Reaction Sintered Silicon Carbide Ceramics and Its Production Technology" has a great impact on the processing of the green body and the preparation of the slurry. The ratio and uniformity of mixing are extremely strict, and because the grouting molding process is formed by the gypsum mold water absorption method, the wall thickness is controlled by the time and amount of slurry suction, and the slurry has a certain amount of precipitation. There are certain errors, so the wall thickness of grouting molding is difficult to achieve consistency, especially the longer the upper and lower head products, the greater the difference, which makes it difficult to achieve consistency in wall thickness control, and the density of the green body is limited and inconsistent, resulting in products Low and uneven density, low production efficiency, high cost waste, and unstable product performance

[0004] The patent number is CN20091009837.6 titled "Preparation Method of Silicon Carbide Ceramic Tube or Rod". Vacuum mud refining, extrusion, drying at 60-100°C for 6-12 hours, drying at 120-150°C for 1-3 hours, pre-calcination at 60-100°C for 1-3 hours, vacuum sintering at 1850-2200°C for 1-3 hours, etc. , therefore, the production efficiency is low and the cost is high

[0005] The patent number is CN95100358 titled "A Method for One-time Firing of Silicon Carbide Recrystallized Products by Cold Extrusion". Low product density and poor uniformity

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