Continuous silicon carbide fiber preparation method and production device

A technology of silicon carbide fiber and production device, which is applied in the directions of chemical characteristics of fibers, complete sets of equipment for producing artificial threads, melt spinning method, etc., can solve the problems that continuous silicon carbide fiber products are difficult to obtain polycarbosilane fibrils without melting treatment, etc. Achieve the effect of high production efficiency, good performance and simple equipment

Active Publication Date: 2011-03-30
苏州赛力菲陶纤有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for preparing continuous silicon carbide fibers, which solves the problems in the prior art that products w

Method used

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  • Continuous silicon carbide fiber preparation method and production device
  • Continuous silicon carbide fiber preparation method and production device
  • Continuous silicon carbide fiber preparation method and production device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] Example 1 Preparation of ceramic precursor polycarbosilane

[0041] Polycondensate dimethyldichlorosilane and metal sodium in xylene to obtain polydimethylsilane, neutralize with methanol and wash with water to dry to obtain white solid powder;

[0042] The white solid powder is decomposed into CPS, a liquid substance mainly composed of cyclosilane, at an appropriate temperature of 200-500°C.

[0043] Add 120-160 kg of CPS into a 300-liter rearrangement polymerization reactor with an external heating and ring-opening cracking system, fill it with pure nitrogen, heat it to 300-350°C, and turn on the external heating device at 200-550°C. Strictly control the liquid reflux rate, rearrange polymerization, gradually (heating rate 0.1 ℃ / min) to 360 ~ 490 ℃, heat preservation 10 ~ 20 hours.

[0044] Stop heating, and after cooling to a certain temperature (200-250°C), a viscous yellow-brown liquid is obtained. Dissolve the yellow-brown liquid and xylene (weight ratio) = 1:4-6...

Embodiment 2

[0045] Example 2 Preparation of continuous SiC fiber

[0046] Put 20 kg of polycarbosilane whose softening point and melting range conform to melt spinning (generally, the softening point is 180-240°C, and the melting range is 8-20°C), put it in the melt-spinning device, and gradually heat it to a certain temperature under the protection of nitrogen flow. Temperature (generally controlled at 250-380°C), adjust the molecular weight distribution, heat preservation and aging for 2-10 hours, carry out spinning with 200-hole spinnerets, obtain a continuous temperature of more than 1000 meters, a diameter of 10-18 microns, and a broken wire rate controlled at 2-5% polycarbosilane fibers, using a unique air oxidation crosslinking, control the degree of crosslinking at 70-90% (the degree of Si-H bond reaction in polycarbosilane fibers is controlled at 60-85%) and then wait Tension plied into fiber bundles (generally 400-1200 / bundle) (the schematic diagram of fiber tension machinery is...

Embodiment 3

[0047] Example 3 Fiber physical property test without applying tension.

[0048] As in the operating conditions in Example 2, if no tension is applied when the fibers are plied, the tensile strength of the obtained continuous SiC fiber (batch SC100810-1) is significantly lower than the mechanical properties in Example 2. The tensile strength of the continuous SiC fiber obtained by the same test method is 1.5GPa, the strength CV value is 23-77%, the tensile modulus is 143.2GPa, the modulus CV value is 20%, and the fiber diameter is 12.9μm. while using as image 3 The continuous SiC fiber (batch SC100811) prepared by the tension device has a tensile strength of 1.8GPa, a strength CV value of 12%, a tensile modulus of 142GPa and a fiber diameter of 13.1μm.

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Abstract

The invention discloses a continuous silicon carbide fiber preparation method, which is characterized by comprising the following steps: (1) preparing a polycarbosilane ceramic precursor by using a precursor conversion process; (2) heating and melting the polycarbosilane ceramic precursor under the protection of an inert gas, and forming polycarbosilane fibril by spinning under the action of a pressure; (3) performing the infusible treatment of the polycarbosilane fibril in an atmosphere of an oxidizing gas to increase the molecular weight of the polycarbosilane fibril by 6 to 20 weight percent with oxidization; and (4) combining strands of infusible polycarbosilane fibril to make a polycarbosilane fibril beam, and continuously passing the polycarbosilane fibril beam through a high-temperature furnace at 1,100 to 1,400 DEG C under vacuum or the protection of the inert gas for firing into the continuous silicon carbide fibers. The method can prepare continuous SiC fibers with high performance and long continuous length; the equipment required by the method is simple; the process flow adopted by the method is short; and production efficiency is high.

Description

technical field [0001] The invention belongs to the technical field of preparation of continuous silicon carbide fibers, and in particular relates to a preparation method of continuous silicon carbide fibers. Background technique [0002] High-performance silicon carbide (SiC) fibers are made by thermally decomposing and rearranging polydimethylsilane into polycarbosilane (PCS), and then using PCS as a precursor to melt spinning, non-melting treatment and high-temperature firing. have to. SiC fiber not only has unique properties such as high strength, high modulus, excellent high temperature oxidation resistance, and chemical corrosion resistance, but also SiC fiber itself is a semiconductor material (resistivity is about 106.cm), by changing the raw material composition or The preparation process conditions can adjust the resistivity of the silicon carbide fiber, making it a wave-absorbing material (the fiber has the best wave-absorbing performance when the resistivity is ...

Claims

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Application Information

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IPC IPC(8): D01F9/10C04B35/565C04B35/622D01D5/08D01D13/02
Inventor 张卫中
Owner 苏州赛力菲陶纤有限公司
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