Device for preparing silicon carbide fiber by direct current heating CVD method and preparation method of silicon carbide fiber

Abstract

The invention belongs to a preparation technology of a silicon carbide fiber, and relates to improvements on a device for preparing the silicon carbide fiber by a direct current heating chemical vapor deposition (CVD) method and a preparation method of the silicon carbide fiber. The preparation device comprises an unwinding disc [6], a winding disc [7], a pretreatment chamber [8] made of a glass tube, a coating chamber [9] made of a glass tube, and deposition chambers [10] and mercury seals [5] which are positioned between the pretreatment chamber [8] and the coating chamber [9], and is characterized in that: 2 to 4 deposition chambers [10] are arranged between the pretreatment chamber [8] and the coating chamber [9]; and the mercury seals [5] are arranged among adjacent deposition chambers [10]. By the device which is provided with a plurality of deposition chambers and is used for preparing the silicon carbide fiber by the direct current heating CVD method and the preparation method of the silicon carbide fiber, a temperature difference between the front and rear ends of each deposition chamber is reduced, and the structural homogeneity of SiC coatings is improved; coatings with a large deposition temperature difference are coated by controlling the temperature of each deposition chamber; and the mixing uniformity of gas in each deposition chamber is improved, the influence of gas impurities on the deposition process is reduced, and the performance of the fiber is ensured.

Description

technical field [0001] The invention belongs to the preparation technology of silicon carbide fibers, and relates to the improvement of a device and a preparation method for preparing silicon carbide fibers by a direct current electric heating method. Background technique [0002] SiC fiber has the advantages of high strength and high hardness, high thermal stability and oxidation resistance, low thermal expansion coefficient and low density. It is also a new type of ceramic material that has developed rapidly in recent years. Making SiC with the above characteristics into fibers is the best reinforcing material for high-temperature ceramic matrix composites and can be widely used to prepare reinforcing fibers for high-performance composites. [0003] SiC fiber-reinforced Ti-based composites combine the high strength, high rigidity and high creep resistance of SiC long fibers with the damage tolerance of titanium alloys, and SiC fibers can reduce the density of materials, w...

AI Technical Summary

Problems solved by technology

[0007] At present, for the preparation of carbon core (tungsten core) silicon carbide fibers, a single deposition chamber is used abroad. The deposition chamber is very long and has multiple gas inlets. Different inlets enter different reaction gases. In this way, the temperature difference between the front and rear ends of the deposition chamber is large, resulting in uneven structure of the deposited SiC coating; since it is a single deposition chamber, the deposition temperature for preparing the fiber coating is determined by the temperature of the deposition chamber, and different coatings require different deposition temperatures. The deposition chamber cannot meet the different deposition temperatures required by different coatings, so the prepared coatings are limited, so it is impossible to coat coatings with a large difference in deposition temperature

Using a single deposition chamber to prepare SiC fibers, the gas is mixed unevenly in the deposition chamber, and the pipeline is too long, so that the gas impurities cannot be discharged quickly, which affects the performance of the fiber

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