SiC hollow sphere and preparation method of same

Abstract

The invention discloses a SiC hollow sphere and a preparation method of same. The preparation method includes the steps of: 1) mixing raw materials, including flake graphite, starch and water, and forming carbon template spheres in a pelletizing machine, placing the carbon template spheres in a roll-forming machine, adding SiC powder, in several batches, into the roll-forming machine to form a SiChollow sphere green body internally coated with the carbon template sphere, and drying and calcining the green body to remove the carbon template sphere to obtain a SiC hollow sphere green body; 2) compacting the surfaces of the SiC hollow sphere green body in the step 1) through a precursor vacuum impregnation pyrolysis process or a chemical vapor deposition process. The light-weight and high-strength SiC hollow sphere has high density and high compression resistance, has uniform and controllable size and smooth and compact surface, can reach 10-50 MPa in compression resistance, and can be widely applied to light packing, catalysis materials, heat preservation and insulation materials, fire-proofing and water-proofing materials, anti-radiation materials, etc.

Description

Technical field [0001] The invention belongs to the technical field of hollow ceramic material molding, and in particular relates to a lightweight and high-strength SiC hollow ball and a preparation method thereof. Background technique [0002] Hollow sphere is a new type of inorganic material developed since the 1870s. This material has a special physical structure and excellent chemical properties, such as low density, large specific surface area, good stability, and surface penetration. Capability, corrosion resistance, self-lubrication, insulation, light reflection, non-toxicity and other characteristics, hollow spheres are used in many fields such as building materials, chemistry and chemical engineering, machinery manufacturing, aerospace, military, etc., and have become a hot spot for scientists and engineers in recent years. . [0003] SiC is an ideal hollow sphere material. It has the characteristics of high hardness, high strength, high stability, high thermal conductivi...

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Problems solved by technology

[0004] Due to the difficulty in the preparation of hollow spherical materials, and the fact that SiC itself is difficult to sinter and compact, so far, there are few related reports on the preparation of SiC hollow spheres in my country. Not only is the molding process complicated, but the prepared SiC hollow spheres cannot achieve light weight and high strength. Requirements limit its promotion and application

[0005] In related domestic patents, such as patent 201510473670.X, phenol and formaldehyde are heated under alkaline conditions to prepare prepolymers, and then tetraethyl orthosilicate and polymer templates are introduced under acidic conditions to obtain carbon silicon Dispersed gel, nano-silicon carbide hollow spheres are prepared by high-temperature carbonization and oxygen passage to remove excess carbon cores. The patented preparation process is complicated, and the process of SiC hollow spheres generated by chemical reactions is difficult to control. At the same time, the obtained SiC hollow spheres are small in size and high in strength. Low

In patent 201110437012.7, carbon black, flour and water are used as raw materials, kneaded and formed, and then extruded into template balls, and ceramic hollow ball green bodies are prepared by throwing ceramic powder rolling balls at one time. After natural drying, low temperature Calcination, medium temperature calcination and high temperature calcination to prepare ceramic hollow spheres, but SiC material is difficult to sinter. Under normal pressure, adding sintering aids still requires a high temperature of 2100-2200°C to sinter densely, which consumes a lot of energy and costs a lot. , it is difficult to prepare lightweight and high-strength SiC hollow spheres at low cost and in large quantities in this way

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