A kind of method for preparing sic/sic composite material pin by dipping and cracking method of precursor

Abstract

The invention belongs to the field of composite material manufacture, and relates to a method for manufacturing SiC / SiC composite material pin with a precursor infiltration and pyrolysis method. The method is characterized in that firstly, a 1K SiC fiber bundle is taken as a raw material; a fiber prefabricate of the pin is manufactured by adopting a 2D weaving mode; the pin fiber prefabricate is placed in a graphite mould for moulding, and then an interface layer is manufactured through chemical vapor infiltration (CVI); a base body is manufactured through precursor infiltration and pyrolysis (PIP), so that the SiC / SiC composite material pin is manufactured; and the manufactured SiC / SiC composite material pin is high in strength and good in tenacity. Compared with an original two-dimensional stacking structure composite material pin, the SiC / SiC composite material pin has the advantages that no layering problem exists; and before being manufactured into the pin, the two-dimensional stacking structure composite material needs to be cut and manufactured into long-strip-shaped firstly, and then is subjected to pin moulding manufacture, so that layering and performance lowering of the composite material are easily caused, and the two-dimensional stacking structure composite material pin is high in manufacture cost and low in efficiency. According to the method, the manufacture efficiency and mechanical performance stability of the pin are improved, and the method has a wide market promotion and application prospect.

Description

technical field [0001] The invention belongs to the field of composite material preparation, and relates to a method for preparing SiC / SiC composite material pins by a precursor dipping and cracking method. Background technique [0002] SiC / SiC is a high-temperature-resistant, low-density ceramic-based thermal structural composite material, which is used in high-thrust-to-weight ratio aircraft engines, satellite attitude control engines, hypersonic ramjet engines, space round-trip heat protection systems, cruise missile engines, liquid and solid rocket engines It has broad prospects for promotion and application in the field of weapons and equipment. [0003] Connection is one of the key issues to be solved for SiC / SiC composite materials to be applied in engineering. The low-cost manufacturing of complex and precise components of SiC / SiC composites needs to realize the connection between SiC / SiC. At present, there have been quite extensive researches on the connection meth...

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Problems solved by technology

The low-cost manufacturing of complex and precise components of SiC / SiC composites needs to realize the connection between SiC / SiC. At present, there have been quite extensive researches on the connection methods of ceramic materials at home and abroad, but the connection of fiber-reinforced ceramic matrix composites There are few researches on the method, especially the research on the connection of SiC / SiC composite materials is still in its infancy. The connection methods of SiC / SiC composite materials at home and abroad are generally divided into three types: one is welding, and the disadvantage of this connection method is mainly low connection strength, And because solder is added to the connection, new problems will arise in the composite material during high-temperature service; the second type is bolted connection, which needs to be threaded, and processing defects are likely to be caused during the process of processing the thread, which will affect the performance of the composite material. damage, and high processing costs; the third is pin connection. At present, the fiber prefabricated body connected by pins generally adopts a two-dimensional laminated structure. This structure is likely to cause damage to the performance of the composite material and delamination damage during the process of processing the pins. And the processing cost and scrap rate are high, these defects seriously limit the engineering application of SiC / SiC composite materials in the field of related high-temperature thermal structural materials

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