Graphene/silicon carbide nano-composite structure monolithic ceramic and preparation method thereof

Abstract

The invention provides graphene / silicon carbide nano-composite structure monolithic ceramic and a preparation method thereof, and relates to preparation of a ceramic material. The preparation method comprises the following steps: 1) synthesizing a precursor PCS(GOx); and 2) preparing the graphene / silicon carbide nano-composite structure monolithic ceramic SiC(rGOx). Precursor PCS(GOx) powder is prepared from raw materials comprising GO, VTES and PCS through a chemical modification method, and then the compact graphene / silicon carbide nano-composite structure monolithic ceramic SiC(rGOx) is obtained through the steps of compression molding forming and high-temperature pyrolysis. The VTES has a -Si-O-bond and a -CH=CH2 group, so the GO and the PCS can be compounded to generate a new GO-VTES-PCS macromolecular structure. The GO is compounded to the silicon carbide ceramic, so that the crosslinking area of the precursor can be enlarged obviously, formation of the SiC nano-crystal is inhibited, the sintering temperature is reduced, and the problems that the silicon carbide monolithic ceramic prepared by a precursor method is difficult to form and low in compactness are solved.

Description

technical field [0001] The invention relates to the preparation of ceramic materials, in particular to a graphene / silicon carbide nanocomposite monolithic ceramic and a preparation method thereof. Background technique [0002] Silicon carbide ceramics not only have the advantages of corrosion resistance, wear resistance, high hardness, good chemical stability, and low thermal expansion coefficient at room temperature, but also exhibit excellent mechanical properties at high temperatures, and are widely used in electronics, machinery, nuclear energy, etc. At present, it can be prepared by reaction sintering, hot pressing sintering and atmospheric pressure sintering. Patent ZL 200910020810.2 discloses a method for preparing silicon carbide-based reinforced composite ceramics. After molding and siliconizing and sintering at 1450-1550°C, a ceramic material with good strength and toughness is obtained. Patent ZL 200910098377.4 discloses a method for preparing carbonized ceramics...

AI Technical Summary

Problems solved by technology

Although silicon carbide prepared by the precursor method shows good performance in low-dimensional forms (fibers, films, coatings, etc.), the preparation technology of three-dimensional ceramic materials such as silicon carbide monolithic ceramics, bulk ceramics, and ceramic matrix composites has not yet been developed. There are some problems, such as high production costs, a large number of SiC nanocrystals precipitated in the product, and the difficulty of forming large-area silicon carbide monolithic ceramics is particularly prominent

During the pyrolysis process of the precursor, a large amount of gaseous substances are released slowly, which will cause defects such as cracks and pores in the monolithic ceramics and bulk ceramics, which seriously affects the density of the product, thus limiting the use of the precursor method to prepare silicon carbide ceramics in the industry. application on

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