Al technical title is built by PatSnap Al team. It summarizes the technical point description of the patent document.
A coated fiber, crack-free technology, applied in the field of preparation of crack-free coated fiber, can solve the problems of many cracks, cracking of coating or substrate, cracking of coating and substrate, etc.
Active Publication Date: 2013-10-02
CENT SOUTH UNIV
View PDF2 Cites 17 Cited by
Summary
Abstract
Description
Claims
Application Information
AI Technical Summary
This helps you quickly interpret patents by identifying the three key elements:
Problems solved by technology
Method used
Benefits of technology
Problems solved by technology
The above method is good, but Academician Zhang Litong of Northwestern Polytechnical University pointed out 【2】 , since there are fewer reinforcing fibers available for selection, and the C base is not resistant to oxidation, a better method is still needed
②The CMC-MS method is the multi-layer self-healing method, and its effect is also very good; but the disadvantages are: 1) Due to B 2 o 3 The temperature at which the fiber becomes viscous is above 650°C, while the C fiber has begun to oxidize at 370°C, that is, the matrix cracks in the temperature range of 370°C to 650°C cannot be formed by the liquid B 2 o 3 To fill, and CMC-SiC has relatively many cracks in this temperature range, making its oxidation resistance very poor
2)B 2 o 3 Very sensitive to water vapor, easy to make B 2 o 3 Layer peeling off, in addition, when the temperature reaches 815°C, B 2 o 3 The diffusion rate of oxygen is very high. When the temperature is above 1000℃, B 2 o 3 The vapor pressure is too high, the oxygen diffusion rate is too high, and it is no longer protective 【3】 , and the higher the temperature, the more serious the volatilization
3) SiO2 2 The high-temperature vapor pressure is small, and the diffusion rate of oxygen is small, but S...
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more
Image
Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
Click on the blue label to locate the original text in one second.
Reading with bidirectional positioning of images and text.
Smart Image
Examples
Experimental program
Comparison scheme
Effect test
Embodiment 1
[0114] In this example, T300 carbon fiber (12), SiC coating (3), the relevant characteristics of SiC coating (3) and T300 carbon fiber (12) are shown in Table 1; no crack coating fiber was prepared, and the gravity loading device (9) Using gravity loading, the method is as follows:
[0115] Step 1, depositing a weak interface layer. First degumming at 600 °C, and then uniformly depositing a 0.3 μm pyrolytic carbon PyC interface layer on T300 carbon fiber (12), the deposition device uses such as Figure 13 In the device shown, the raw material is high-purity acetylene gas, and the protective gas is Ar gas. During the CVD deposition process, since the thickness of the interface layer is very thin, tension can be applied to the T300 carbon fiber (12), and the pyrolytic carbon layer can also be deposited without tension, which has little influence on the force of the anti-oxidation coating.
[0116] Step 2, under the action of tension, uniformly deposit the anti-oxidation coatin...
Embodiment 2
[0126] This embodiment adopts carbon fiber (12), B 4 C coating (3), preparation of crack-free coated fibers, B 4 The relevant characteristics of C coating and C fiber are shown in Table 3. The gravity loading device (9) adopts gravity loading, and the CVD deposition device such as Figure 14 ,Methods as below:
[0127] Step 1, depositing a weak interface layer. First, degumming is performed at a temperature of 600°C in the degumming furnace 30, and a 0.3 μm pyrolytic carbon PyC interface layer is evenly deposited on the carbon fiber (12). The deposition device adopts such as Figure 14 For the pyrolytic carbon high-temperature deposition furnace (31) shown, the raw material is high-purity acetylene gas, and the protective gas is high-purity N 2 . During CVD deposition, a layer of pyrolytic carbon may be deposited by applying tension to the carbon fibers (12).
[0128] Step 2, under the action of tension, uniformly deposit the anti-oxidation coating. The anti-oxidation co...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
PUM
Login to view more
Abstract
The invention relates to a preparation method of a crack-free coating fiber, and belongs to the technical field of preparation of a composite material. After initial tensile stress sigma o is exerted to continuous single fibers or fiber bundles, an anti-oxidation coating is evenly deposited on the surface by using a CVD (chemical vapor deposition) method and the like under the condition of tensile stress; the initial tensile stress sigma o is unloaded under the condition that the initial tensile stress is greater than or equal to the crack generating temperature TC of the coating after deposition is ended; the anti-oxidation coating is integrally cooled to room temperature after the initial tensile stress sigma o is unloaded, so as to obtain the crack-free coating fiber. By adopting the preparation method, a thermal stress crack caused by mismatching of thermal expansion of the fiber and the coating is avoided; a channel of an oxidizing medium is cut off; the fiber is prevented from being oxidized; anti-oxidation protection of a full-temperature section is achieved. Thus, the integrality, the safety and the reliability of the composite material are improved; the preparation method is suitable for preparation of heat-resistant, anti-oxidation and high-temperature creep-resistant reinforced composites. Therefore, the preparation method is continuous and simple in preparation technology, and convenient to industrially produce.
Description
technical field [0001] The invention relates to a preparation method of a crack-free coating fiber, belonging to the technical field of composite material preparation. Background technique [0002] C fiber-reinforced SiC-based ceramic composites (CMC—SiC), the performance is obvious to all, but due to the thermal expansion mismatch between the C fiber and the SiC matrix, the SiC matrix cracks, and it has very good anti-oxidation performance and protection at high temperatures. Functional SiC matrix, however, due to the cracks in the matrix, the oxidizing medium can be exploited. Due to the oxidation channels provided by the cracks, the performance of CMC-SiC is seriously affected. In order to prevent the C fiber from being oxidized, researchers have thought of various methods, and the more effective methods are: ① Crack closing method, which is to use the difference in thermal expansion coefficient between the fiber and the matrix to heal the crack, so that the oxidizing me...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more
Application Information
Patent Timeline
Application Date:The date an application was filed.
Publication Date:The date a patent or application was officially published.
First Publication Date:The earliest publication date of a patent with the same application number.
Issue Date:Publication date of the patent grant document.
PCT Entry Date:The Entry date of PCT National Phase.
Estimated Expiry Date:The statutory expiry date of a patent right according to the Patent Law, and it is the longest term of protection that the patent right can achieve without the termination of the patent right due to other reasons(Term extension factor has been taken into account ).
Invalid Date:Actual expiry date is based on effective date or publication date of legal transaction data of invalid patent.
Login to view more 
Login to view more