CN102924106B

CN102924106B - Method for preparing carbon-silicon carbon composite material and product thereof

Info

Publication number: CN102924106B
Application number: CN201210488169.7A
Authority: CN
Inventors: 林文松
Original assignee: Shanghai University of Engineering Science
Current assignee: Shanghai University of Engineering Science
Priority date: 2012-11-27
Filing date: 2012-11-27
Publication date: 2014-04-02
Anticipated expiration: 2032-11-27
Also published as: CN102924106A

Abstract

The invention discloses a method for preparing a carbon-silicon carbon composite material and a product prepared by the method, wherein the preparation comprises the following steps: firstly, weaving carbon fibers into a three-dimensional stereo textile (hereinafter referred to as carbon fiber preformed body); depositing a layer of simple substance silicon which is 0.1-2 mu m thick on the carbon fiber preformed body by the vapor deposition technique; proportionally preparing phenolic resin, carbon black, ethanol, ultra-thin silicon carbon powder, polyvinylpyrrolidone and tetramethylammonium hydroxide into the mixed slurry; pressurizing the slurry in the vacuum environment so that the slurry outflows to soak the carbon fiber preformed body to obtain a composite material green body; heating and solidifying the green body; and then putting the solidified green body in a vacuum furnace and arousing a high-temperature siliconing reaction, thereby obtaining the high-density, high-performance carbon-silicon carbon composite material.

Description

A kind of preparation method of carbon fiber reinforced silicon carbide matrix composite

Technical field

The invention belongs to field of inorganic nonmetallic material, relate to the preparation technology of matrix material, especially a kind of preparation method of carbon fibre reinforced silicon carbide ceramic composite.

Background technology

In silicon carbide ceramics, add continuous carbon fibre, prepare carbon fibre reinforced silicon carbide (C _f/ SiC) matrix material, carbon fiber the mechanism such as extracts by crack deflection, fiber in ceramic breaking-down process, can strengthen intensity and the toughness of stupalith.

Existing C _fthe preparation technology of/SiC matrix material mainly contains: chemical vapour deposition (CVI) technique, precursor infiltration and pyrolysis (PIP) technique, mud dipping hot pressing (SIHP) technique, liquid impregnation (LSI) technique etc.

The technological process of CVI is that carbon fiber preform is placed in to CVI stove, and reactant gases is delivered to preform backward its internal divergence around by the directed flow being produced by pressure difference, at fiber surface generation chemical reaction in-situ deposition.CVI technique is prepared C _fthe major advantage of/SiC matrix material be can be at the temperature far below body material fusing point synthesize ceramic matrix, reduce the fibre property that the high-temperature chemical reaction between fiber and matrix brings and decline; The integrity that can also keep fibre preforms body structure in preparation process, realizes near-net-shape and prepares complex-shaped goods.But it is very long that CVI technique also exists preparation cycle, along gas diffusion path, there is larger density difference, the defects such as the remaining a large amount of void content of matrix material.

SIHP technological process is that SiC powder, sintering aid powder and organic binder bond etc. are made to mud by solvent, and carbon fiber is spun into non-woven fabrics, the molded rear hot pressed sintering of slice module after mud dipping.The densification of material mainly completes by liquid-phase sintering process.The C manufacturing by SIHP method _f/ SiC matrix material density is higher, and defect is less, is comparatively applicable to preparing unidirectional composite material.But SIHP method has larger difficulty to preparation complex shaped components, and carbon fiber tends to and SiC matrix generation surface reaction under High Temperature High Pressure, cause fibre property to decline, be unfavorable for improving the performance of material.

PIP legal system is for C _fthe conventional process of/SiC matrix material is to adopt organic precursor liquid solution impregnation of carbon fibers preform under certain temperature and pressure, after crosslinking curing, carries out Pintsch process under protection of inert gas, makes precursor be converted into SiC ceramic matrix.The preparation temperature of PIP method is low, can with no pressurely burn till, less to the machinery of fiber and chemical damage, and can prepare the member of large complicated shape.But the shortcoming of this kind of technique also clearly, and material densification needs several dipping-lytic cycles, and the production cycle is longer; And owing to can produce small molecule by-product in Pintsch process process, from matrix, overflow, the porosity of resulting materials is higher, has more difficultly prepared fully dense material; Easily there is the chemical reaction of certain form in precursor and fiber, on the one hand fiber is badly damaged in cracking process, forms on the other hand the interfacial layer of strong combination, causes material toughness not high.

LSI technique comprises three primary processes: first prefabricated carbon fiber part is put into airtight mould, adopt high pressure stamp or resin transfer mold technique to prepare fiber reinforced polymer materials; Then cracking in high temperature inert environment, obtains low density carbon based composites (C _f/ C); Finally adopt melt Si under vacuum by the wicking action processing of infiltrating, Si melt is reacted with carbon base body and generates SiC matrix.This technique can be by adjusting C _fthe volume density of/C and porosity are controlled the density of final matrix material.The preparation cycle of LSI technique is short, cost is low, residual porosity rate is low, can prepare dead size, complex-shaped workpiece; But this technique is Shortcomings also: melt Si, when reacting with carbon base body, inevitably can react with carbon fiber, and fiber is etched and causes degradation.

The present invention has overcome above-mentioned defect.

Summary of the invention

The object of the invention is to overcome the deficiency of above-mentioned prior art, the advantages of three kinds of techniques such as LSI, CVI and PIP is got up, provide a kind of and can either improve C _fthe problem that/SiC matrix material density is low, also can effectively hinder the preparation technology of Si to the erosion action of carbon fiber.

Technical scheme of the present invention is achieved by following processing step:

1) by diameter, be that the carbon fiber knit of 6 ~ 8 μ m becomes three dimension stereo fabric, obtain carbon fabric perform;

2) in vacuum tightness, be 1 * 10 ^-2~ 5 * 10 ^-3in the vacuum oven of Pa, at the carbon fiber surface vapour deposition layer of metal silicon of carbon fabric perform;

3) ultra fine silicon carbide powder, carbon black, resol, polyvinylpyrrolidone, Tetramethylammonium hydroxide and ethanol are mixed with to mixed slurry in following ratio after ball milling: 63 ~ 72 parts of silicon carbide powders, 5 ~ 6 parts of carbon blacks, 1.5 ~ 2 parts, resol, 0.5 ~ 1.0 part of Tetramethylammonium hydroxide, 0.1 ~ 0.5 part of polyvinylpyrrolidone, 40 ~ 45 parts of alcohol;

4) carbon fabric perform is positioned in graphite jig, under subatmospheric environment, mixed slurry is applied to the pressure of 0.1 ~ 2.0 MPa, its impregnating by pressure is obtained to composite body in above-mentioned carbon fabric perform;

5) above-mentioned composite body and mould are incubated to 2 hours together under 100 ℃ of temperature condition and carry out baking and curing processing;

6) by above-mentioned, carried out base substrate that baking and curing processes and mould to be placed on together vacuum tightness be 1 * 10 ^-2~ 1 * 10 ^-3in the vacuum oven of Pa, be warming up to 1450 ~ 1550 ℃ and carry out high temperature siliconising reaction, make carbon fiber reinforced silicon carbide matrix composite.

With respect to prior art, the present invention has the following advantages:

1. preparation technology provided by the invention carries out at lower temperature, can significantly reduce the damage of reaction process to carbon fiber;

2. with respect to existing technology of preparing, the preparation flow of technique of the present invention is short, and preparation time significantly reduces;

3. the C that prepared by the present invention _f/ SiC matrix material has the high-compactness close to theoretical density.

Embodiment

Below in conjunction with two specific embodiments, the present invention is further understood in exemplary illustration and help.But embodiment detail is only for the present invention is described, do not represent the whole technical schemes of the present invention under conceiving, therefore should not be construed as the restriction to technical scheme of the present invention.Some do not depart from the unsubstantiality of the present invention's design changes, for example, to have simple the change or replacement of technical characterictic of same or similar technique effect, all belong to rights protection scope of the present invention.

Embodiment 1

A preparation method for carbon fiber reinforced silicon carbide matrix composite, preparation technology comprises the following steps:

Step 1, the carbon fiber knit that is 6 ~ 8 μ m by mean diameter becomes three dimension stereo fabric (being called carbon fabric perform below);

Step 2, puts into an airtight container by carbon fabric perform, and in container, places Pure Silicon Metal, and itself and carbon fabric perform are isolated; It is 1 * 10 that material in said vesse and container is positioned over to vacuum tightness together ^-2in the vacuum oven of Pa, heat to 1500 ℃, insulation 1h, takes out the carbon fabric perform of processing after furnace cooling;

Step 3, by mean particle size, be silicon carbide powder 72g, carbon black 8g, resol 2g, polyvinylpyrrolidone 0.2g, Tetramethylammonium hydroxide 0.5g and the ethanol 40ml of 0.1 μ m, put into high energy ball mill, and add the agate abrading-ball of 300g, after ball milling 5h, be mixed with mixed slurry;

Step 4, is positioned over carbon fabric perform in graphite jig, and 0.5MPa that mixed slurry is pressurizeed under the vacuum environment of 0.01 MPa, is impregnated in above-mentioned carbon fabric perform and obtains composite body;

Step 5, arises from 100 ℃ of insulation 2h by above-mentioned base substrate and mould one and carries out baking and curing processing;

Step 6, it is 1 * 10 that above-mentioned base substrate and mould are placed on to vacuum tightness together ^-3in the vacuum oven of Pa, be warming up to 1500 ℃ and carry out high temperature siliconising reaction, obtain high-compactness, high performance carbon/composite silicon carbide ceramic material.

Embodiment 2

Step 1, the carbon fiber knit that is 6 ~ 8 μ m by mean diameter becomes three-dimensional carbon fiber preform;

Step 2, puts into an airtight container by carbon fabric perform, and in container, places Pure Silicon Metal, and itself and carbon fabric perform are isolated, and it is 5 * 10 that the material in said vesse and container is positioned over to vacuum tightness together ^-3in the vacuum oven of Pa, heat to 1500 ℃, insulation 3h, takes out the carbon fabric perform of processing after furnace cooling;

Step 3, by mean particle size, be silicon carbide powder 63g, carbon black 7g, resol 2g, polyvinylpyrrolidone 0.3g, Tetramethylammonium hydroxide 0.5g and the ethanol 40ml of 0.22 μ m, put into high energy ball mill, and add the agate abrading-ball of 300g, after ball milling 5h, be mixed with mixed slurry;

Step 4, is positioned over carbon fabric perform in graphite jig, mixed slurry is applied under the vacuum environment of 0.01 MPa to the pressure of 0.2 MPa, is impregnated in above-mentioned carbon fabric perform and obtains composite body;

Step 6, it is 1 * 10 that above-mentioned base substrate and mould are placed on to vacuum tightness together ^-3in the vacuum oven of Pa, be warming up to 1480 ℃ and carry out siliconising reaction, obtain high-compactness, high performance carbon-silicon carbide ceramic composite.

Claims

1. a preparation method for carbon fiber reinforced silicon carbide matrix composite, is characterized in that preparation method comprises the steps:

Step 1, the carbon fiber knit that is 6 ~ 8 μ m by diameter becomes three dimension stereo fabric, obtains carbon fabric perform;

Step 2 is 1 * 10 in vacuum tightness ^-2~ 5 * 10 ^-3in the vacuum oven of Pa, at the carbon fiber surface vapour deposition layer of metal silicon of carbon fabric perform;

Step 3 is mixed with mixed slurry by ultra fine silicon carbide powder, carbon black, resol, polyvinylpyrrolidone, Tetramethylammonium hydroxide and ethanol in following ratio after ball milling: 63 ~ 72 parts of silicon carbide powders, 5 ~ 6 parts of carbon blacks, 1.5 ~ 2 parts, resol, 0.5 ~ 1.0 part of Tetramethylammonium hydroxide, 0.1 ~ 0.5 part of polyvinylpyrrolidone, 40 ~ 45 parts of ethanol;

Step 4, is positioned over carbon fabric perform in graphite jig, under subatmospheric environment, mixed slurry is applied to the pressure of 0.1 ~ 2.0 MPa, and its impregnating by pressure is obtained to composite body in above-mentioned carbon fabric perform;

Step 5 is incubated 2 hours together by above-mentioned composite body and mould and carries out baking and curing processing under 100 ℃ of temperature condition;

Step 6, carried out base substrate that baking and curing processes and mould to be placed on together vacuum tightness was 1 * 10 above-mentioned ^-2~ 1 * 10 ^-3in the vacuum oven of Pa, be warming up to 1450 ~ 1550 ℃ and carry out high temperature siliconising reaction, make carbon fiber reinforced silicon carbide matrix composite.

2. according to the preparation method of the carbon fiber reinforced silicon carbide matrix composite described in right 1, it is characterized in that:

In step 2, at the fiber surface of carbon fabric perform, adopting the layer of metal silicon thickness of vapour deposition process deposition is 0.1 ~ 2 μ m.

3. according to the preparation method of the carbon fiber reinforced silicon carbide matrix composite described in right 1 or 2, it is characterized in that:

The granularity of the mixed slurry using in step 3 is 0.05 ~ 0.25 μ m.