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

Abstract

The invention discloses a three-layer core-spun silicon carbide fiber wire, which comprises a SiC fiber core wire, wherein a polytetrafluoroethylene middle layer is arranged on the outer side of the SiC fiber core wire, an aramid fiber outer wrapping layer is arranged on the outermost layer, and the three-layer core-spun silicon carbide fiber wire is suitable for sewing of a two-dimensional SiC fiber preform, so that a two-dimensional SiC / SiC composite material is prepared. According to the invention, the characteristics of wear resistance and the like of the aramid yarn are used as the outerwrapping layer to wrap the SiC fiber core wire with the polytetrafluoroethylene middle layer, so that the three-layer core-spun wire with the closed and round outer layer and the core wire not easy tobreak is prepared, and the SiC fiber is ensured not to be in direct contact with the SiC fiber cloth when penetrating into and out of the laminated SiC fiber cloth as a suture line, so that frictionforce and extrusion stress borne by the SiC fiber suture line are reduced, the integrity and continuity of the SiC fiber suture line after suture are ensured, and the problem that a traditional carbonfiber suture line is prone to breakage is solved.

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-coated silicon carbide fiber wire. Background technique [0002] Silicon carbide reinforced silicon carbide ceramic matrix composite (SiC / SiC) has become the most potential thermal structural material in the field of aerospace because of its 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, generally including four structural units: reinforcing fiber, 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 the design of composite components, it needs to be woven into various prefabricated bodies. Among them, the planar t...

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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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