Preparation method and application of three-layer core-spun silicon carbide fiber wire

Abstract

The three-layer core-wrapped silicon carbide fiber wire of the present invention includes a SiC fiber core wire, the outer side of the SiC fiber core wire is a polytetrafluoroethylene intermediate layer, and the outermost layer is an aramid outer wrapping layer, which is suitable for a two-dimensional SiC fiber preform stitching to prepare two-dimensional SiC / SiC composites. The invention uses the characteristics of aramid yarn wear resistance and other characteristics as the outer wrapping layer, wraps the SiC fiber core wire with the polytetrafluoroethylene intermediate layer, and prepares the three-layer core-wrapped wire whose outer layer is closed and round and the core wire is not easily broken, thereby ensuring When the SiC fiber is used as a suture, it does not directly contact with the SiC fiber cloth when it penetrates into and out of the laminated SiC fiber cloth, which reduces the frictional force and extrusion stress on the SiC fiber suture and ensures the integrity of the SiC fiber suture after stitching. It has good stability and continuity, and solves the problem of easy thread breakage when using traditional carbon fiber as suture.

Description

technical field [0001] The invention belongs to the technical field of textile fiber preparation, and relates to a preparation method and application of a three-layer core-spun silicon carbide fiber wire. Background technique [0002] Silicon carbide reinforced silicon carbide ceramic matrix composites (SiC / SiC) have become the most potential thermal structural materials in the aerospace field due to their low density, high strength, high modulus, high temperature resistance, and oxidation resistance. application prospects. Ceramic matrix composites are composed of high-strength ceramic fibers and ceramic matrix, and generally include four structural units: reinforcing fibers, interface phase, matrix and coating. The reinforcing fiber is equivalent to the skeleton of the composite material and is the main load-bearing structural unit. When it is applied to composite component design, it needs to be woven into various prefabricated bodies. Among them, the planar two-dimens...

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Problems solved by technology

However, due to the mismatch of thermal expansion coefficients between carbon fiber and SiC / SiC composite components, the matrix is ​​prone to cracks and other defects due to thermal stress during the heating-cooling cycle of the densification process, which affects the final quality of the composite material. mechanical properties

In addition, carbon fiber is easy to oxidize at high temperature. For some practical application environments with high temperature and oxygen, the carbon fiber between layers is easy to oxidize and fail, which reduces the interlayer bonding force of composite materials and affects the application range of two-dimensional SiC / SiC composite materials.

For two-dimensional stitched SiC / SiC composite materials, SiC fiber is the most ideal choice as the stitching thread. It is not only resistant to high temperature and oxidation, but also thermally matched with the components of the composite material. However, due to the high modulus of SiC fiber itself, in During the sewing process, it is easy to cause the suture to break due to the frictional resistance between the cloth and the extrusion stress, which reduces the quality of the suture and is not conducive to the bonding between layers, thereby reducing the overall performance of the composite material

At present, there are no related reports or patents on the preparation of 2D SiC / SiC composite materials by suturing SiC fibers

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