CN115111439A - Large-wall-thickness ceramic-based composite pipe fitting and preparation method thereof - Google Patents
Large-wall-thickness ceramic-based composite pipe fitting and preparation method thereof Download PDFInfo
- Publication number
- CN115111439A CN115111439A CN202210750346.8A CN202210750346A CN115111439A CN 115111439 A CN115111439 A CN 115111439A CN 202210750346 A CN202210750346 A CN 202210750346A CN 115111439 A CN115111439 A CN 115111439A
- Authority
- CN
- China
- Prior art keywords
- thin
- wall pipe
- pipe fitting
- wall
- core
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002131 composite material Substances 0.000 title claims abstract description 49
- 238000002360 preparation method Methods 0.000 title claims abstract description 48
- 239000000919 ceramic Substances 0.000 title claims abstract description 28
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 54
- 239000011153 ceramic matrix composite Substances 0.000 claims abstract description 40
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 21
- XJKVPKYVPCWHFO-UHFFFAOYSA-N silicon;hydrate Chemical compound O.[Si] XJKVPKYVPCWHFO-UHFFFAOYSA-N 0.000 claims abstract description 10
- 238000000151 deposition Methods 0.000 claims description 72
- 230000008021 deposition Effects 0.000 claims description 69
- 239000004744 fabric Substances 0.000 claims description 61
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 56
- 239000000835 fiber Substances 0.000 claims description 43
- 238000009958 sewing Methods 0.000 claims description 42
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 33
- 238000000034 method Methods 0.000 claims description 33
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 33
- 238000003754 machining Methods 0.000 claims description 30
- 229910052786 argon Inorganic materials 0.000 claims description 28
- 238000012545 processing Methods 0.000 claims description 27
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 24
- 239000001257 hydrogen Substances 0.000 claims description 24
- 229910052739 hydrogen Inorganic materials 0.000 claims description 24
- DWAWYEUJUWLESO-UHFFFAOYSA-N trichloromethylsilane Chemical compound [SiH3]C(Cl)(Cl)Cl DWAWYEUJUWLESO-UHFFFAOYSA-N 0.000 claims description 24
- 238000007493 shaping process Methods 0.000 claims description 22
- 239000012043 crude product Substances 0.000 claims description 18
- 238000004804 winding Methods 0.000 claims description 18
- 239000011248 coating agent Substances 0.000 claims description 14
- 238000000576 coating method Methods 0.000 claims description 14
- 239000012495 reaction gas Substances 0.000 claims description 12
- 238000005229 chemical vapour deposition Methods 0.000 claims description 11
- 239000000758 substrate Substances 0.000 claims description 11
- 238000013461 design Methods 0.000 claims description 10
- 229910052799 carbon Inorganic materials 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 8
- 239000011159 matrix material Substances 0.000 claims description 7
- 238000005137 deposition process Methods 0.000 claims description 6
- 238000011049 filling Methods 0.000 claims description 6
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 6
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 6
- 238000007789 sealing Methods 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 5
- 238000004140 cleaning Methods 0.000 claims description 4
- 238000001035 drying Methods 0.000 claims description 4
- 239000012808 vapor phase Substances 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 abstract description 13
- 238000000280 densification Methods 0.000 abstract description 9
- 239000010410 layer Substances 0.000 description 76
- 229910002804 graphite Inorganic materials 0.000 description 25
- 239000010439 graphite Substances 0.000 description 25
- 239000000463 material Substances 0.000 description 10
- 238000005520 cutting process Methods 0.000 description 8
- 229920000049 Carbon (fiber) Polymers 0.000 description 6
- 239000004917 carbon fiber Substances 0.000 description 6
- 239000011148 porous material Substances 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 5
- 230000035515 penetration Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical group C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000011229 interlayer Substances 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 238000003892 spreading Methods 0.000 description 2
- 238000003466 welding Methods 0.000 description 2
- 238000010923 batch production Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L9/00—Rigid pipes
- F16L9/10—Rigid pipes of glass or ceramics, e.g. clay, clay tile, porcelain
Abstract
The invention relates to a ceramic matrix composite pipe fitting and a preparation method thereof, in particular to a large-wall-thickness ceramic matrix composite pipe fitting and a preparation method thereof. Solves the technical problems that the existing large-wall-thickness ceramic matrix composite pipe fitting is difficult to prepare, has nonuniform densification, long production period and the like. The large-wall-thickness ceramic-based composite pipe fitting comprises a core thin-wall pipe fitting, a plurality of middle thin-wall pipe fittings and an outermost thin-wall pipe fitting, wherein the core thin-wall pipe fitting is sleeved with the middle thin-wall pipe fittings; draft angles are arranged on the outer molded surface of the core thin-wall pipe fitting and the inner molded surface of the outermost thin-wall pipe fitting; the inner and outer molded surfaces of the middle thin-wall pipe fitting are respectively provided with a draft angle; the adjacent molded surfaces of the thin-wall pipe fittings are matched; the outer molded surfaces of the core thin-wall pipe fitting and the middle thin-wall pipe fitting are respectively provided with a plurality of grooves; the groove and the adjacent thin-wall pipe fitting form a gap, and the gap is filled with a thick solution of silicon carbide powder and water. The invention also provides a preparation method of the ceramic matrix composite pipe fitting with the large wall thickness.
Description
Technical Field
The invention relates to a ceramic matrix composite pipe fitting and a preparation method thereof, in particular to a large-wall-thickness ceramic matrix composite pipe fitting and a preparation method thereof.
Background
In the prior art, due to the limitation of the CVI (chemical vapor deposition) forming process technology of the ceramic matrix composite, the ceramic matrix composite pipe with large wall thickness is difficult to prepare, the density uniformity of the prepared material is poor, the production period is long, and the functional application and expansion of the ceramic matrix pipe in multiple fields are greatly limited, so that the technical bottleneck problem of the preparation of the ceramic matrix composite pipe with large wall thickness is urgently solved.
The Chinese patent with the publication number of CN111170751A discloses a CVI densification method for a ceramic matrix composite part with large wall thickness. According to the method, when the part is densified to a certain range through a CVI technology, the guide holes are formed in the thickness direction of the part, and then the densification degree can be further increased in the area near the guide holes. However, the method has the defects that the surface of the large-wall-thickness composite part and the area near the flow guide hole are densified to reach the standard, and the area far away from the surface and the area of the flow guide hole still has the phenomenon of poor densification degree, namely, the qualified densification false image exists during the overall evaluation of the densification degree of the composite material, the leakage risk of the flow guide hole is increased for the parts with sealing requirements, such as pipes and the like, after the flow guide hole is formed, and meanwhile, the influence of the number and the pore diameter of the formed flow guide hole on the strength of the ceramic-based composite material with the fiber microporous structure is difficult to estimate.
Disclosure of Invention
The invention aims to solve the technical problems that the existing large-wall-thickness ceramic-based composite pipe is difficult to prepare, the densification is uneven, the production period is long, the product quality risk is large and the like, and provides the large-wall-thickness ceramic-based composite pipe and the preparation method thereof. The preparation method can greatly improve the preparation quality and the production efficiency of the ceramic-based pipe fitting with the large wall thickness, and the prepared ceramic-based pipe fitting with the large wall thickness can meet the use requirements.
The technical scheme of the invention is as follows:
a ceramic matrix composite pipe fitting with large wall thickness is characterized in that:
comprises n thin-wall pipe fittings which are connected in a sleeved mode, wherein n is more than or equal to 3;
the n thin-wall pipe fittings comprise a core thin-wall pipe fitting, and n-2 middle thin-wall pipe fittings and outermost thin-wall pipe fittings which are sequentially sleeved on the core thin-wall pipe fitting from inside to outside;
the inner molded surface of the core thin-wall pipe fitting is cylindrical, and one end of the outer molded surface is provided with a draft angle;
the outer molded surface of the outermost layer thin-wall pipe fitting is cylindrical, and one end of the inner molded surface is provided with a draft angle;
the inner and outer molded surfaces of the middle thin-wall pipe fitting are provided with draft angles;
the draft angle angles of the core thin-wall pipe fitting, the middle thin-wall pipe fitting and the outermost thin-wall pipe fitting are the same;
the adjacent molded surfaces of the core thin-wall pipe fitting, each middle thin-wall pipe fitting and the outermost thin-wall pipe fitting are matched;
the wall thickness of the core thin-wall pipe fitting and the wall thickness of the outermost thin-wall pipe fitting are 3-6 mm; the wall thickness of the middle thin-wall pipe fitting is 2-6 mm;
the outer molded surfaces of the core thin-wall pipe fitting and the middle thin-wall pipe fitting are both provided with a plurality of grooves which penetrate through the outer molded surfaces along the axial direction along the circumferential direction; the groove and the adjacent thin-wall pipe fitting form a gap, and the gap is filled with a thick solution of silicon carbide powder and water; the mass ratio of the silicon carbide powder to the water is 4.5-5.5: 10-12;
the grooves on the adjacent thin-wall pipe fittings are arranged in a staggered manner.
Further, the relationship between the length L of each thin-wall pipe fitting and the draft angle satisfies the following condition: the length L of the thin-wall pipe fitting is more than or equal to 0.1 and less than or equal to 300mm, and the draft angle is 0.5-0.7 degrees; the length L of the thin-wall pipe fitting is more than 300 and less than 600mm, and the draft angle is 0.4-0.5 degrees; the length L of the thin-wall pipe fitting is more than or equal to 600 and less than or equal to 800mm, and the draft angle is 0.3-0.4 degrees.
Further, the relationship between the total wall thickness t of the core thin-walled tube, the intermediate thin-walled tube and the outermost thin-walled tube and the number n of thin-walled tubes is:
n＝t/6+1。
further, the width of the groove (100) is 3-4 mm; the mass ratio of the silicon carbide powder to the water is 5: 11.
further, each of said grooves is formed by machining an axially extending flat surface in the outer profile of the core thin-walled tube or the intermediate thin-walled tube.
Meanwhile, the invention also provides a preparation method of the ceramic matrix composite pipe fitting with the large wall thickness, which is characterized by comprising the following steps:
1) preparing a plurality of fiber cloth layers of carbon cloth or silicon carbide cloth with different sizes, and preparing an interface layer;
2) shaping the prefabricated body;
2.1) shaping the core thin-wall pipe prefabricated body;
winding a corresponding fiber cloth layer prepared by an interface layer on a die of the core thin-wall pipe fitting, and sewing to ensure that the reserved machining allowance of the inner profile of the core thin-wall pipe fitting preform is 0.5-1 mm, and the reserved machining allowance of the outer profile of the core thin-wall pipe fitting preform is 0.5-1 mm, so as to obtain the core thin-wall pipe fitting preform with the required thickness;
2.2) shaping the thin-wall pipe fitting preform at the outermost layer;
winding a corresponding fiber cloth layer prepared by the interface layer on a die of the outermost thin-wall pipe fitting, and sewing to ensure that the reserved processing allowance of the inner profile of the outermost thin-wall pipe fitting preform is 0.5-1 mm, and the reserved processing allowance of the outer profile of the outermost thin-wall pipe fitting preform is 0.5-1 mm, so as to obtain the outermost thin-wall pipe fitting preform with the required thickness;
2.3) shaping n-2 intermediate thin-wall pipe fitting preforms;
winding a corresponding fiber cloth layer prepared by an interface layer on a mould of each middle thin-wall pipe fitting, and sewing to ensure that the reserved machining allowance of the inner profile of the middle thin-wall pipe fitting preform is 0.5-1 mm, and the reserved machining allowance of the outer profile of the middle thin-wall pipe fitting preform is 0.5-1 mm, so as to obtain n-2 middle thin-wall pipe fitting preforms;
3) respectively densifying the core thin-wall pipe preform, the n-2 middle thin-wall pipe preforms and the outermost thin-wall pipe preform by a chemical vapor deposition process to respectively obtain 1.80g/cm 3 ～2.0g/cm 3 The core thin-wall pipe fitting preform, the n-2 middle thin-wall pipe fitting preforms and the outermost thin-wall pipe fitting preform;
4) thin-wall pipe fitting processing
4.1) respectively processing the outer molded surface of the core thin-wall pipe fitting preform, the inner molded surface of the outermost thin-wall pipe fitting preform and the inner molded surface and the outer molded surface of n-2 middle thin-wall pipe fitting preforms to meet the design requirements, and simultaneously ensuring that the tolerance of the outer conical surface of each thin-wall pipe fitting is-0.10 to-0.05 mm and the tolerance of the inner conical surface is +0.05 to +0.10 mm;
4.2) respectively processing grooves on the outer molded surfaces of the core thin-wall pipe prefabricated body and the middle thin-wall pipe to obtain a core thin-wall pipe prefabricated body and n-2 middle thin-wall pipes;
5) nested assembly
5.1) nesting and assembling the core thin-wall pipe fitting prefabricated body, n-2 middle thin-wall pipe fittings and the outermost thin-wall pipe fitting prefabricated body, and arranging the grooves on the adjacent thin-wall pipe fittings in a staggered manner to obtain a crude product of the composite pipe fitting;
5.2) cleaning and drying the crude product of the composite pipe fitting;
5.3) filling dense liquid of silicon carbide powder and water into a gap formed by the groove on the thin-wall pipe fitting and the adjacent thin-wall pipe fitting for sealing; the mass ratio of the silicon carbide powder to the water is 4.5-5.5: 10-12;
6) depositing a silicon carbide substrate on the crude product of the composite pipe fitting;
7) superfinishing the inner and outer molded surfaces and the axial dimension of the crude product of the composite pipe fitting after the silicon carbide substrate is deposited, and ensuring that the tolerance of the inner diameter is +0.10 to +0.15mm, the tolerance of the outer diameter is-0.15 to-0.10 mm, and the tolerance of the length is 0 to 0.15 mm;
8) and (3) preparing the high-temperature-resistant silicon carbide coating on the crude product of the composite pipe fitting by a chemical vapor phase process to obtain the ceramic-based composite pipe fitting with large wall thickness.
Further, in step 1), the process for preparing the interface layer comprises: the deposition temperature is 650-750 ℃, the deposition time is 40-50 h, and the gas and flow are respectively 6-9L/min of propylene and 3-4L/min of argon; the vacuum degree is less than 1000 Pa.
Further, in step 3), the chemical vapor deposition process is: the deposition time is 40-45 h, the deposition temperature is 850-1000 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.3L/min-0.35L/min, the hydrogen flow is 0.40 +/-0.2L/min, and the trichloromethylsilane flow is 0.35 +/-0.2L/min.
Further, in step 6), the deposition process of the silicon carbide substrate is as follows: the deposition time is 50-55 h, the deposition temperature is 850-1000 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.35L/min-0.4L/min, the hydrogen flow is 0.45 +/-0.2L/min, and the trichloromethylsilane flow is 0.4 +/-0.2L/min.
Further, in the step 8), the process for preparing the high-temperature resistant silicon carbide coating comprises the following steps: the deposition time is 30-35 h, the deposition temperature is 900-1000 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.25L/min-0.3L/min, the hydrogen flow is 0.35 +/-0.1L/min, and the trichloromethylsilane flow is 0.3 +/-0.2L/min.
The invention has the beneficial effects that:
1. according to the ceramic matrix composite pipe fitting with the large wall thickness, disclosed by the invention, the structure of the ceramic matrix composite pipe fitting with the large wall thickness is disassembled into a plurality of thin-wall pipe fittings to be independently prepared according to the characteristics of the preparation process of the ceramic matrix composite, and compared with the preparation of common ceramic matrix large-wall-thickness parts, the ceramic matrix composite pipe fitting with the large wall thickness has the advantages that: a. the preparation period is short; b. the single thin-wall part and the combined whole have high densification degree and good density uniformity; c. the combination mode is nimble convenient, can carry out the design of compound material density of wall thickness direction according to different pipe fitting performance demands.
2. The ceramic matrix composite pipe fitting with the large wall thickness can be assembled according to the required thickness, the requirements of different wall thickness conditions are met, and meanwhile, the structure of the ceramic matrix composite pipe fitting is simple and convenient to disassemble and install.
3. According to the large-wall-thickness ceramic matrix composite pipe fitting, the drawing angles are arranged on the single thin-wall pipe fitting, so that the subsequent combined assembly is facilitated, the production efficiency is improved, and the corresponding relation between the drawing angle setting and the pipe fitting length is determined in order to meet the requirements of pipe fittings with different lengths.
4. The maximum wall thickness of each thin-wall pipe fitting of the large-wall-thickness ceramic-based composite pipe fitting is less than or equal to 6 mm; the maximum wall thickness is limited by considering the optimal penetration thickness of CVI deposition gas, the CVI preparation efficiency and quality are easy to control only when the CVI deposition gas does not exceed 6mm, and the CVI deposition effect and the uniformity of deposition density are poor when the wall thickness exceeds 6mm, so that the performance of the pipe fitting is influenced.
5. The grooves are formed in the thin-wall pipe fitting at the core part and the middle thin-wall pipe fitting in the large-wall-thickness ceramic-based composite pipe fitting, and the gaps formed between the grooves and the adjacent thin-wall pipe fittings are filled with the dense solution of silicon carbide powder and water, so that the thick solution can be used as a rivet welding agent deposited by CVI after assembly to form a pinning effect on the assembly surface of each thin-wall pipe fitting, the thin-wall pipe fittings are prevented from rotating and sliding, and the influence of the assembly quality of the thin-wall pipe fittings on the performance of the large-wall-thickness pipe fittings is reduced. In addition, the grooves are formed by processing a plane extending along the axial direction on the outer molded surface of the core thin-wall pipe fitting or the middle thin-wall pipe fitting, the processing is simple, and the performance of the pipe fitting is not greatly influenced.
6. The large-wall-thickness ceramic-based composite pipe fitting provided by the invention provides the relation between the number of layers, the number n of thin-wall pipe fittings and the total wall thickness of the composite pipe fitting, and the whole number of the disassembled layers can be obtained by adjusting the wall thickness of the thin-wall pipe fitting at the middle interlayer part.
7. The invention relates to a preparation method of a ceramic matrix composite pipe fitting with large wall thickness, which improves the preparation time of an interface layer after shaping a fiber preform, and has the advantages that a fiber cloth layer is firstly unfolded to prepare the interface layer and then is sewn and shaped, compared with the conventional method that the interface layer is prepared after the preform is sewn and shaped, the preparation method has the following steps: a. the interface layer is more uniform: the conventional method of firstly shaping and then preparing the interface has obvious interface gradient along the thickness direction of the prefabricated body, is not beneficial to subsequent matrix deposition and influences the material performance and the structural strength; b. the production cycle is saved, and the mass production is facilitated: the problem of conventional design earlier the interface preparation need many heats deposit repeatedly when later, compressed interface preparation heat, production efficiency is higher to can carry out interface preparation with the fiber cloth in advance, carry out the preform design according to the difference of compound material design structure again, practice thrift production cycle, be convenient for batch production.
8. The preparation method of the ceramic-based composite pipe with the large wall thickness performs unified processing after assembly, realizes the composite forming reference, unifies the processing reference and the process control reference, is suitable for quickly preparing the ceramic-based composite pipe with the large wall thickness, and has important significance for improving the production efficiency and the preparation precision of the composite pipe.
9. The preparation method of the ceramic-based composite pipe fitting with the large wall thickness greatly improves the deposition speed of the thin-wall pipe fitting, on one hand, the interface layer is relatively uniform due to the preparation of the interface layer on the cloth layer in the step 1, and on the other hand, the deposition efficiency and quality of a CVI matrix are remarkably improved due to the fact that the structure is disassembled into the single thin-wall pipe fitting for independent deposition, and the wall thickness is small.
Drawings
FIG. 1 is a schematic structural diagram of an embodiment of a large wall thickness ceramic matrix composite pipe fitting according to the present invention;
FIG. 2 is an exploded view of an embodiment of the ceramic matrix composite pipe of the present invention;
FIG. 3 is an axial cross-sectional view of FIG. 1;
FIG. 4 is an enlarged view of a portion of FIG. 3A;
FIG. 5 is a schematic end view of the structure of FIG. 1;
FIG. 6 is an enlarged view of a portion of FIG. 5 at B;
FIG. 7 is a schematic view of a thin-walled tube with a core according to an embodiment of the present invention;
FIG. 8 is an axial cross-sectional view of FIG. 7;
FIG. 9 is a schematic structural diagram of a middle thin-walled tube according to an embodiment of the present invention;
FIG. 10 is an axial cross-sectional view of FIG. 9;
FIG. 11 is a schematic structural diagram of an outermost thin-walled tube according to an embodiment of the present invention;
FIG. 12 is an axial cross-sectional view of FIG. 11;
FIG. 13 is a process flow diagram of a method for manufacturing a ceramic matrix composite pipe fitting with a large wall thickness according to the present invention.
Reference numerals:
1-ceramic matrix composite pipe fitting with large wall thickness, 10-core thin-wall pipe fitting, 11-middle thin-wall pipe fitting and 12-outermost thin-wall pipe fitting; 100-grooves, 2-spaces.
Detailed Description
The invention is further described with reference to the following figures and specific embodiments.
As shown in FIGS. 1 to 6, the ceramic matrix composite pipe with large wall thickness of the invention comprises n thin-wall pipes which are connected in a sleeving manner, wherein n is more than or equal to 3; the n thin-wall pipe fittings comprise a core thin-wall pipe fitting 10, and n-2 middle thin-wall pipe fittings 11 and outermost thin-wall pipe fittings 12 which are sequentially sleeved on the core thin-wall pipe fitting 10 from inside to outside. The relationship between the total wall thickness t of the core thin-walled tube 10, the middle thin-walled tube 11 and the outermost thin-walled tube 12 and the number n of thin-walled tubes is as follows: n is t6+ 1. In this embodiment, the length L of the large-wall ceramic matrix composite pipe 1 is 600mm, the inner diameter phid is 60mm, and the outer diameter phid is 120mm, so that
If n is a non-integer, the calculation is carried out according to the close maximum integer, the rounding is realized by adjusting the wall thickness of the middle thin-wall pipe 11 at the middle interlayer part, and the wall thickness of the middle thin-wall pipe 11 is ensured to be 2-6 mm.
As shown in fig. 7 and 8, the inner profile of the thin-walled tube core 10 is cylindrical, and one end of the outer profile is provided with a draft angle. As shown in fig. 11 and 12, the outer profile of the outermost thin-walled tube 12 is cylindrical, and one end of the inner profile is provided with a draft angle. As shown in fig. 9 and 10, the inner and outer profiles of the intermediate thin-walled tube 11 are provided with draft angles. The angles of the draft angles of the core thin-walled tube member 10, the intermediate thin-walled tube member 11, and the outermost thin-walled tube member 12 are all the same. The relationship between the length L and the draft angle of each thin-wall pipe fitting meets the following conditions: the length L of the thin-wall pipe fitting is more than or equal to 0.1 and less than or equal to 300mm, and the draft angle is 0.5-0.7 degrees; the length L of the thin-wall pipe fitting is more than 300 and less than 600mm, and the draft angle is 0.4-0.5 degrees; the length L of the thin-wall pipe fitting is more than or equal to 600 and less than or equal to 800mm, and the draft angle is 0.3-0.4 degrees. Therefore, in this embodiment, L is 600mm, so the tube drawing angle α is 0.3 °. Each thin-wall pipe fitting is assembled by means of the combination of the drawing angles. The invention aims to facilitate the nesting assembly of the thin-wall pipe fittings and improve the assembly quality of the pipe fittings by arranging the drawing angle on at least one side surface in the outer profile or the inner profile of the thin-wall pipe fittings. Wherein, n-2 middle thin-wall pipe fittings 11 positioned in the middle interlayer are pipe fittings with equal wall thickness, and the inner and outer shapes are provided with drawing angles.
In the large-wall-thickness ceramic matrix composite pipe fitting 1, the outer profile of the core thin-wall pipe fitting 10 is matched with the inner profile of the closest middle thin-wall pipe fitting 11, the inner profile and the outer profile of the adjacent middle thin-wall pipe fitting 11 are matched, the inner profile of the outermost thin-wall pipe fitting 12 is matched with the outer profile of the closest middle thin-wall pipe fitting 11, namely the adjacent profiles of the core thin-wall pipe fitting 10, each middle thin-wall pipe fitting 11 and each outermost thin-wall pipe fitting 12 are matched. The wall thickness of the core thin-wall pipe 10 and the wall thickness of the outermost thin-wall pipe 12 are 3-6 mm; the wall thickness of the middle thin-wall pipe 11 is 2-6 mm. Because the CVI (chemical vapor infiltration) which is usually adopted in the process of preparing and forming the ceramic-based composite material is suitable for preparing the composite material with the wall thickness not more than 6mm, in order to ensure the preparation performance of the material and take the preparation efficiency and the cost into consideration, the wall thickness of a single thin-wall pipe fitting is not more than 6 mm.
In order to adapt to the requirements of different pipe fitting performances and use conditions and solve the problem of local clearance or poor assembly quality of the conical surface of a single thin-wall pipe fitting, a plurality of grooves 100 which penetrate through the core thin-wall pipe fitting 10 and the middle thin-wall pipe fitting 11 along the circumferential direction are arranged on the outer molded surfaces of the core thin-wall pipe fitting 10 and the middle thin-wall pipe fitting 11, and each groove 100 is formed by processing a plane which extends along the axial direction on the outer molded surface of the core thin-wall pipe fitting 10 or the middle thin-wall pipe fitting 11. The width of the groove 100 on the single core thin-wall pipe 10 or the single middle thin-wall pipe 11 is 3-4 mm; the grooves 100 on the adjacent thin-wall pipe fittings are arranged in a staggered way. After n thin-wall pipe fittings are assembled, the groove 100 and the adjacent thin-wall pipe fittings form a gap 2, the gap 2 is filled with a thick solution of silicon carbide powder and water, and the mass ratio of the silicon carbide powder to the water is 4.5-5.5: 10-12. The thick solution of silicon carbide powder and water in the gap 2 has the function of being used as a rivet welding agent deposited by CVI after assembly, and forms a pinning effect on the assembly surface of each thin-wall pipe fitting, so that the thin-wall pipe fittings are prevented from rotating and sliding, and the influence of the assembly quality of the thin-wall pipe fittings on the performance of the large-wall pipe fittings is reduced.
Meanwhile, the invention also provides a preparation method of the ceramic matrix composite pipe fitting with the large wall thickness, as shown in fig. 13, the preparation method comprises the following steps:
1) preparing a plurality of fiber cloth layers of carbon cloth or silicon carbide cloth with proper sizes, and preparing interface layers;
1.1) preparing a plurality of fiber cloth layers of carbon cloth or silicon carbide cloth with proper sizes, and spreading the fiber cloth layers of the enhanced phases of the ceramic matrix composite materials such as the carbon cloth/the silicon carbide cloth along the cloth width to ensure the tidiness of the cloth layers;
1.2) placing the unfolded cloth layer into an interface preparation deposition furnace for preparing an interface layer; the preparation process of the interface layer comprises the following steps: the deposition temperature is 650-750 ℃, the deposition time is 40-50 h, and the gas and flow are respectively 6-9L/min of propylene and 3-4L/min of argon; the vacuum degree is less than 1000 Pa.
2) Shaping the prefabricated body;
2.1) shaping the core thin-wall pipe prefabricated body;
winding a corresponding fiber cloth layer prepared by an interface layer on a graphite mould of the core thin-wall pipe fitting 10, sewing, wherein the sewing fiber is carbon fiber, the specification of a fiber tow is 1K, a mode of sewing by opposite penetration around an axis is adopted, the sewing hole of the preform is consistent with the processed hole position on the graphite mould, and the sewing span is ensured to be 5-8 mm; the graphite mould is cylindrical, the outer diameter of the graphite mould is 0.5-1 mm smaller than the inner diameter of the core thin-wall pipe 10, the reserved machining allowance of the inner profile surface of the core thin-wall pipe preform is 0.5-1 mm, the reserved machining allowance of the outer profile surface of the core thin-wall pipe preform is 0.5-1 mm, and the core thin-wall pipe preform with the required thickness is obtained;
2.2) shaping the outermost thin-wall pipe fitting preform;
winding a corresponding fiber cloth layer prepared by the interface layer on a graphite mould of the thin-walled tube fitting 12 on the outermost layer, sewing, wherein the sewing fiber is carbon fiber, the specification of a fiber tow is 1K, a mode of sewing by opposite penetration around an axis is adopted, the sewing hole of the preform is consistent with the processed hole position on the graphite mould, and the sewing span is ensured to be 5-8 mm; ensuring that the reserved machining allowance of the inner profile of the outermost layer thin-wall pipe fitting preform is 0.5-1 mm, and the reserved machining allowance of the outer profile of the outermost layer thin-wall pipe fitting preform is 0.5-1 mm, so as to obtain the outermost layer thin-wall pipe fitting preform with the required thickness;
2.3) shaping n-2 intermediate thin-wall pipe fitting preforms;
winding the corresponding fiber cloth layers prepared by the interface layer on a graphite mold (with taper) of each middle thin-wall pipe fitting 11 respectively, sewing, wherein the sewing fibers are carbon fibers, the specification of fiber tows is 1K, the sewing mode of the fiber tows passing through the graphite mold around the axis is adopted, the sewing holes of the prefabricated body are consistent with the processed hole positions on the graphite mold, and the sewing span is ensured to be 5-8 mm; and (3) the shaping surface of the graphite mould is smaller than the inner shape of the middle thin-wall pipe fitting by 0.5-1 mm, the reserved processing allowance of the inner shape surface of the middle thin-wall pipe fitting preform is 0.5-1 mm, and the reserved processing allowance of the outer shape surface of the middle thin-wall pipe fitting preform is 0.5-1 mm, so that n-2 middle thin-wall pipe fitting preforms are obtained.
If the graphite mold of the intermediate thin-walled tube 11 has no taper, it can be manufactured by the following method: respectively winding a corresponding fiber cloth layer prepared by an interface layer on a mould of each middle thin-wall pipe 11, wherein the outer diameter of the mould is 0.5-1 mm smaller than the inner diameter of each middle thin-wall pipe, cutting the fiber cloth layer after winding for 3 circles (the appearance of the prefabricated body is cylindrical at this moment), padding a whole circle of fan-shaped cloth at the cutting position of the outer shape of the prefabricated body, continuously winding the fan-shaped cloth around the outer shape, ensuring that the padding cloth axially surrounds the prefabricated body to form a conical surface, arranging the cutting openings of the fiber cloth layer and the cutting openings of the fan-shaped padding cloth in a staggered manner, ensuring that the outer shape of the prefabricated body is 0.5-1 mm larger than the outer shape of the finally assembled middle thin-wall pipe 11, and completing n-2 middle thin-wall pipe prefabricated bodies with required thickness and size.
3) Respectively placing each thin-wall pipe fitting in a CVI deposition furnace, keeping the furnace loading direction of the pipe fitting parallel to the incoming flow direction of the reaction atmosphere, ensuring that the contact reaction quantity of the reaction atmosphere and the internal and external types of the pipe fitting tend to be consistent, and performing densification by a chemical vapor deposition process to respectively obtain 1.80g/cm 3 ～2.0g/cm 3 The core thin-wall pipe fitting preform, the n-2 middle thin-wall pipe fitting preforms and the outermost thin-wall pipe fitting preform;
the chemical vapor deposition process comprises the following steps: the deposition temperature is 850-1000 ℃, the deposition time is 40-45 h, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.3L/min-0.35L/min, the hydrogen flow is 0.40 +/-0.2L/min, and the trichloromethylsilane flow is 0.35 +/-0.2L/min.
The deposition rate of each thin-wall pipe fitting is greatly improved, mainly because the interface preparation is carried out on the cloth layer in the step 1, the interface layer is uniform, and the large-wall-thickness pipe fitting is disassembled into a plurality of thin-wall pipe fittings for independent deposition, the wall thickness of each pipe fitting is small, so that the deposition efficiency and quality of a CVI matrix can be obviously improved.
4) Thin-walled tube processing
4.1) respectively machining the outer molded surface of the core thin-wall pipe fitting preform, the inner molded surface of the outermost thin-wall pipe fitting preform and the inner molded surface and the outer molded surface of n-2 middle thin-wall pipe fitting preforms by a numerical control machine tool to meet the design requirements, and simultaneously ensuring that the tolerance of the outer conical surface of each thin-wall pipe fitting is-0.10 to-0.05 mm and the tolerance of the inner conical surface is +0.05 to +0.10 mm;
4.2) grooves are respectively processed on the outer molded surfaces of the core thin-wall pipe prefabricated body and the middle thin-wall pipe prefabricated body, the grooves are communicated along the axial direction of the pipes and are uniformly distributed along the circumferential direction of the pipes, and the width of each groove is 3-4 mm; obtaining a core thin-wall pipe prefabricated part and n-2 middle thin-wall pipe fittings 11 after the machining is finished;
5) nested assembly
5.1) nesting and assembling the core thin-wall pipe fitting prefabricated body, n-2 middle thin-wall pipe fittings 11 and the outermost thin-wall pipe fitting prefabricated body, and mounting the grooves on the adjacent thin-wall pipe fittings in a staggered manner to obtain a crude product of the composite pipe fitting; the staggered arrangement of the grooves can improve the permeability of reaction atmosphere along the pores of the grooves in the subsequent deposition process.
5.2) cleaning and drying the crude product of the composite pipe fitting;
5.3) filling dense liquid of silicon carbide powder and water into a gap 2 formed by the groove 100 on the thin-wall pipe fitting and the adjacent thin-wall pipe fitting for sealing; the mass ratio of the silicon carbide powder to the water is 4.5-5.5: 10-12;
6) depositing a silicon carbide substrate on the crude product of the composite pipe fitting;
the silicon carbide substrate deposition process comprises the following steps: the deposition temperature is 850-1000 ℃, the deposition time is 50-55 h, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.35L/min-0.4L/min, the hydrogen flow is 0.45 +/-0.2L/min, and the trichloromethylsilane flow is 0.4 +/-0.2L/min.
7) Carry out numerical control lathe superfinishing to the inside and outside profile and the axial dimension of the compound material pipe fitting crude after the silicon carbide substrate deposit, process the inside and outside profile and the length dimension of big wall thickness ceramic base compound material pipe fitting 1, because there is the influence to the superfinishing size in follow-up coating deposit, consequently need guarantee to add man-hour to the design requirement size of big wall thickness compound material pipe fitting 1 and satisfy: the tolerance of the inner diameter is +0.10 to +0.15mm, the tolerance of the outer diameter is-0.15 to-0.10 mm, and the tolerance of the length is 0 to 0.15 mm;
8) and (3) preparing the high-temperature-resistant silicon carbide coating on the crude product of the composite pipe fitting by a chemical vapor phase process to obtain the ceramic-based composite pipe fitting 1 with large wall thickness. The high-temperature-resistant silicon carbide coating is prepared on the surface of the ceramic-based composite pipe with the large wall thickness, so that the high-temperature resistance of the ceramic-based composite pipe with the large wall thickness can be greatly improved.
The preparation process of the high-temperature resistant silicon carbide coating comprises the following steps: the deposition time is 30-35 h, the deposition temperature is 900-1000 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.25L/min-0.3L/min, the hydrogen flow is 0.35 +/-0.1L/min, and the trichloromethylsilane flow is 0.3 +/-0.2L/min.
The above preparation method is specifically illustrated by the following examples, and it should be noted that only some examples, not all examples, are selected in the present invention.
Example 1
The preparation steps of the large-wall-thickness ceramic matrix composite pipe fitting are as follows:
1) preparing a plurality of fiber cloth layers of carbon cloth/silicon carbide cloth with proper sizes, and preparing interface layers;
1.1) preparing a plurality of fiber cloth layers of carbon cloth/silicon carbide cloth with proper sizes, and spreading the fiber cloth layers of the enhanced phases of the ceramic matrix composite materials such as the carbon cloth/the silicon carbide cloth along the cloth width to ensure the tidiness of the cloth layers;
1.2) placing the unfolded cloth layer into an interface preparation deposition furnace for preparing an interface layer; the preparation process parameters of the interface layer are as follows: the deposition temperature is 700 +/-20 ℃, the deposition time is 42h, and the gas and flow are respectively 7 +/-0.5L/min of propylene and 3.5 +/-0.5L/min of argon; the vacuum degree is less than 1000 Pa.
2) Shaping the prefabricated body;
2.1) shaping the core thin-wall pipe prefabricated body;
winding a corresponding fiber cloth layer prepared by an interface layer on a graphite mould of the core thin-wall pipe fitting 10, sewing, wherein the sewing fiber is carbon fiber, the specification of a fiber tow is 1K, a mode of sewing by opposite penetration around an axis is adopted, the sewing hole of the preform is consistent with the processed hole position on the graphite mould, and the sewing span is ensured to be 6 mm; the graphite mould is cylindrical, the outer diameter of the graphite mould is smaller than the inner diameter of the core thin-wall pipe 10 by 1mm, the reserved machining allowance of the inner profile surface of the core thin-wall pipe preform is ensured to be 1mm, and the reserved machining allowance of the outer profile surface of the core thin-wall pipe preform is ensured to be 1mm, so that the core thin-wall pipe preform with the required thickness is obtained;
2.2) shaping the thin-wall pipe fitting preform at the outermost layer;
winding a corresponding fiber cloth layer prepared by the interface layer on a graphite mould of the thin-wall pipe fitting 12 at the outermost layer, sewing, wherein the sewing fiber is carbon fiber, the specification of a fiber tow is 1K, a mode of sewing by opposite penetration around an axis is adopted, the sewing hole of the preform is consistent with the processed hole position on the graphite mould, and the sewing span is ensured to be 6 mm; the reserved machining allowance of the inner profile of the outermost layer thin-wall pipe fitting prefabricated body is guaranteed to be 1mm, the reserved machining allowance of the outer profile of the outermost layer thin-wall pipe fitting prefabricated body is guaranteed to be 1mm, and the outermost layer thin-wall pipe fitting prefabricated body with the required thickness is obtained;
2.3) shaping n-2 intermediate thin-wall pipe prefabricated bodies;
respectively winding the corresponding fiber cloth layers prepared by the interface layer on the graphite mould (with taper) of each middle thin-wall pipe fitting 11, sewing, wherein the sewing fibers are carbon fibers, the specification of fiber tows is 1K, the sewing holes of the prefabricated body are consistent with the processed hole positions on the graphite mould by adopting an axial line opposite-penetrating sewing mode, and the sewing span is ensured to be 6 mm; and (3) the shaping surface of the graphite mould is smaller than the inner shape of the middle thin-wall pipe fitting by 1mm, the reserved processing allowance of the inner shape surface of the middle thin-wall pipe fitting preform is ensured to be 1mm, and the reserved processing allowance of the outer shape surface of the middle thin-wall pipe fitting preform is 1mm, so that n-2 middle thin-wall pipe fitting preforms are obtained.
3) Respectively placing each thin-wall pipe fitting in a CVI deposition furnace, keeping the furnace loading direction of the pipe fitting parallel to the incoming flow direction of reaction atmosphere, ensuring that the contact reaction quantity of the reaction atmosphere and the internal and external types of the pipe fitting tends to be consistent, and respectively densifying the core thin-wall pipe fitting preform, the n-2 middle thin-wall pipe fitting preforms and the outermost thin-wall pipe fitting preform by a chemical vapor deposition process, wherein the chemical vapor deposition process comprises the following steps: the deposition temperature is 930 +/-20 ℃, the deposition time is 43 hours, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.3L/min-0.35L/min, the hydrogen flow is 0.40 +/-0.2L/min, and the trichloromethylsilane flow is 0.35 +/-0.2L/min. Respectively obtain 1.9g/cm 3 Core thin-wall pipeThe device comprises a prefabricated body, n-2 middle thin-wall pipe prefabricated bodies and an outermost thin-wall pipe prefabricated body;
the deposition rate of each thin-wall pipe fitting is greatly improved, mainly because the interface preparation is carried out on the cloth layer in the step 1, the interface layer is uniform, and the large-wall-thickness pipe fitting is disassembled into a plurality of thin-wall pipe fittings for independent deposition, the wall thickness of each pipe fitting is small, so that the deposition efficiency and quality of a CVI matrix can be obviously improved.
4) Thin-wall pipe fitting processing
4.1) respectively machining the outer molded surface of the core thin-wall pipe fitting preform, the inner molded surface of the outermost thin-wall pipe fitting preform and the inner molded surface and the outer molded surface of n-2 middle thin-wall pipe fitting preforms by a numerical control machine tool to meet the design requirements, and simultaneously ensuring that the tolerance of the outer conical surface of each thin-wall pipe fitting is-0.10 to-0.05 mm and the tolerance of the inner conical surface is +0.05 to +0.10 mm;
4.2) grooves are respectively processed on the outer molded surfaces of the core thin-wall pipe prefabricated body and the middle thin-wall pipe prefabricated body, the grooves are communicated along the axial direction of the pipes and are uniformly distributed along the circumferential direction of the pipes, and the width of each groove 100 is 4 mm; obtaining a core thin-wall pipe prefabricated part and n-2 middle thin-wall pipe fittings 11 after the machining is finished;
5) nested assembly
5.1) nesting and assembling the core thin-wall pipe fitting prefabricated body, n-2 middle thin-wall pipe fittings 11 and the outermost thin-wall pipe fitting prefabricated body, and mounting the grooves on the adjacent thin-wall pipe fittings in a staggered manner to obtain a crude product of the composite pipe fitting; the staggered installation of the grooves can improve the permeability of reaction atmosphere along the pores of the grooves in the subsequent deposition process.
5.2) cleaning and drying the crude product of the composite pipe fitting to ensure that the appearance is clean and has no redundant substances;
5.3) filling dense liquid of silicon carbide powder and water into a gap 2 formed by the groove 100 on the thin-wall pipe fitting and the adjacent thin-wall pipe fitting for sealing; the mass ratio of the silicon carbide powder to the water is 5: 11; when the pore is sealed and filled, the pipe fitting is placed perpendicular to the ground, a clean injector is used for absorbing the silicon carbide solution to be injected into the pore 2 on the end face of the pipe fitting, and the sealing and filling are stopped when no obvious pore exists on the end face of the other side and a small amount of liquid flows out.
6) Depositing a silicon carbide substrate on the crude product of the composite pipe fitting;
the silicon carbide substrate deposition process comprises the following steps: the deposition temperature is 930 +/-20 ℃, the deposition time is 53h, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.35L/min-0.4L/min, the hydrogen flow is 0.45 +/-0.2L/min, and the trichloromethylsilane flow is 0.4 +/-0.2L/min.
7) Carrying out numerical control lathe superfinishing on the inner and outer molded surfaces and the axial dimension of a crude composite pipe fitting after silicon carbide substrate deposition, processing the inner and outer molded surfaces and the length dimension of the large-wall-thickness ceramic-based composite pipe fitting 1, and ensuring that the design requirement dimensional tolerance of the large-wall-thickness composite pipe fitting 1 meets the following conditions during processing because the subsequent coating deposition influences the superfinishing dimension: the tolerance of the inner diameter is +0.10 to +0.15mm, the tolerance of the outer diameter is-0.15 to-0.10 mm, and the tolerance of the length is 0 to 0.15 mm;
8) the preparation method comprises the following steps of carrying out preparation of a high-temperature-resistant silicon carbide coating on a crude product of the composite pipe fitting by a chemical vapor phase process, wherein the preparation process of the high-temperature-resistant silicon carbide coating comprises the following steps: the deposition time is 30h, the deposition temperature is 960 +/-20 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.25L/min-0.3L/min, the hydrogen flow is 0.35 +/-0.1L/min, and the trichloromethyl silane flow is 0.3 +/-0.2L/min, so that the ceramic matrix composite pipe fitting 1 with the large wall thickness is obtained. The high-temperature-resistant silicon carbide coating is prepared on the surface of the ceramic-based composite pipe with the large wall thickness, so that the high-temperature resistance of the ceramic-based composite pipe with the large wall thickness can be greatly improved.
Example 2
This example differs from example 1 in that:
in step 1.2), the preparation process parameters of the interface layer are as follows: the deposition temperature is 670 +/-20 ℃, the deposition time is 40h, and the gas and the flow rate are respectively 6.5 +/-0.5L/min of propylene.
In the step 2.1), the sewing span is ensured to be 8 mm; the outer diameter of the graphite mould is 0.5mm smaller than the inner diameter of the core thin-wall pipe 10, so that the reserved machining allowance of the inner profile surface of the core thin-wall pipe preform is 0.5mm, and the reserved machining allowance of the outer profile surface of the core thin-wall pipe preform is 0.5 mm;
in the step 2.2), the sewing span is ensured to be 8 mm; the reserved machining allowance of the inner profile of the thin-wall pipe fitting prefabricated body on the outermost layer is guaranteed to be 0.5mm, and the reserved machining allowance of the outer profile of the thin-wall pipe fitting prefabricated body on the outermost layer is guaranteed to be 0.5 mm;
in the step 2.3), the sewing span is ensured to be 8 mm; the shaping surface of the graphite mould is 0.5mm smaller than the inner shape of the middle thin-wall pipe fitting, the reserved processing allowance of the inner shape surface of the middle thin-wall pipe fitting prefabricated body is 0.5mm, and the reserved processing allowance of the outer shape surface of the middle thin-wall pipe fitting prefabricated body is 0.5 mm;
in step 3), 1.8g/cm are obtained respectively 3 The core thin-wall pipe fitting preform, the n-2 middle thin-wall pipe fitting preforms and the outermost thin-wall pipe fitting preform;
the chemical vapor deposition process comprises the following steps: the deposition temperature is 830 +/-20 ℃, and the deposition time is 40 h.
In step 4.2), the width of the groove 100 is 3 mm.
In the step 5.3), the mass ratio of the silicon carbide powder to the water is 4.5: 10.
In the step 6), the deposition temperature is 830 +/-20 ℃, and the deposition time is 50 h.
In the step 8), the preparation process of the high-temperature resistant silicon carbide coating comprises the following steps: the deposition time is 32h, and the deposition temperature is 920 +/-20 ℃.
Example 3
This example differs from example 1 in that:
in step 1.2), the preparation process parameters of the interface layer are as follows: the deposition temperature is 730 +/-20 ℃, the deposition time is 50h, and the gas and the flow rate are respectively 8.5 +/-0.5L/min of propylene.
In the step 2.1), the sewing span is ensured to be 5 mm; the outer diameter of the graphite mould is 0.7mm smaller than the inner diameter of the core thin-wall pipe 10, so that the reserved machining allowance of the inner profile surface of the core thin-wall pipe preform is 0.7mm, and the reserved machining allowance of the outer profile surface of the core thin-wall pipe preform is 0.7 mm;
in the step 2.2), the sewing span is ensured to be 5 mm; the reserved processing allowance of the inner profile of the outermost layer thin-wall pipe fitting preform is guaranteed to be 0.5mm, and the reserved processing allowance of the outer profile of the outermost layer thin-wall pipe fitting preform is 0.5 mm;
in the step 2.3), the sewing span is ensured to be 5 mm; the shaping surface of the graphite mould is 0.7mm smaller than the inner shape of the middle thin-wall pipe fitting, the reserved processing allowance of the inner shape surface of the middle thin-wall pipe fitting prefabricated body is 0.7mm, and the reserved processing allowance of the outer shape surface of the middle thin-wall pipe fitting prefabricated body is 0.7 mm;
in step 3), 2.0g/cm was obtained respectively 3 The core thin-wall pipe fitting preform, the n-2 middle thin-wall pipe fitting preforms and the outermost thin-wall pipe fitting preform;
the chemical vapor deposition process comprises the following steps: the deposition temperature is 980 +/-20 ℃, and the deposition time is 45 h.
In step 4.2), the width of the groove 100 is 3.5 mm.
In the step 5.3), the mass ratio of the silicon carbide powder to the water is 5.5: 12.
In the step 6), the deposition temperature is 980 +/-20 ℃, and the deposition time is 55 h.
In the step 8), the preparation process of the high-temperature resistant silicon carbide coating comprises the following steps: the deposition time is 35h, and the deposition temperature is 980 +/-20 ℃.
Example 4
This example differs from example 1 in that:
in the step 2.3), the die of the middle thin-wall pipe 11 is a graphite die without taper, and n-2 middle thin-wall pipe prefabricated bodies are shaped by the following method: respectively winding a corresponding fiber cloth layer prepared by an interface layer on a mould of each middle thin-wall pipe 11, wherein the outer diameter of the mould is smaller than the inner diameter of each middle thin-wall pipe 11 by 1mm, cutting the fiber cloth layer after winding for 3 circles (the appearance of the prefabricated body is cylindrical at this moment), padding a whole circle of fan-shaped cloth at the cutting position of the outer shape of the prefabricated body, continuously winding the fan-shaped cloth around the outer shape, ensuring that the padding cloth surrounds the axial direction of the prefabricated body to form a conical surface, arranging the cutting openings of the fiber cloth layer and the cutting openings of the fan-shaped padding cloth in a staggered manner, ensuring that the outer shape of the prefabricated body is larger than the outer shape of the finally assembled middle thin-wall pipe 11 by 1mm, and obtaining n-2 middle thin-wall pipe prefabricated bodies with required thickness and size.
Claims (10)
1. The utility model provides a ceramic matrix composite pipe fitting of big wall thickness which characterized in that:
comprises n thin-wall pipe fittings which are connected in a sleeved mode, wherein n is more than or equal to 3;
the n thin-wall pipe fittings comprise a core thin-wall pipe fitting (10), and n-2 middle thin-wall pipe fittings (11) and outermost thin-wall pipe fittings (12) which are sequentially sleeved on the core thin-wall pipe fitting (10) from inside to outside;
the inner profile of the core thin-wall pipe fitting (10) is cylindrical, and one end of the outer profile is provided with a draft angle;
the outer profile of the outermost layer thin-wall pipe fitting (12) is cylindrical, and one end of the inner profile is provided with a draft angle;
the inner and outer molded surfaces of the middle thin-wall pipe fitting (11) are provided with draft angles;
the draft angle angles of the core thin-wall pipe (10), the middle thin-wall pipe (11) and the outermost thin-wall pipe (12) are the same;
the adjacent profiles of the core thin-wall pipe (10), the middle thin-wall pipe (11) and the outermost thin-wall pipe (12) are matched;
the wall thickness of the core thin-wall pipe (10) and the wall thickness of the outermost thin-wall pipe (12) are 3-6 mm; the wall thickness of the middle thin-wall pipe (11) is 2-6 mm;
a plurality of grooves (100) which penetrate through the thin-walled tube (10) at the axial direction are formed in the outer molded surface of the core part and the outer molded surface of the middle thin-walled tube (11) along the circumferential direction; the groove (100) and the adjacent thin-wall pipe fitting form a gap (2), and the gap (2) is filled with a thick solution of silicon carbide powder and water;
the mass ratio of the silicon carbide powder to the water is 4.5-5.5: 10-12;
the grooves (100) on the adjacent thin-wall pipe fittings are arranged in a staggered mode.
2. The large wall thickness ceramic matrix composite pipe of claim 1, wherein:
the relationship between the length L and the draft angle of each thin-wall pipe fitting meets the following conditions:
the length L of the thin-wall pipe fitting is more than or equal to 0.1 and less than or equal to 300mm, and the draft angle is 0.5-0.7 degrees;
the length L of the thin-wall pipe fitting is more than 300 and less than 600mm, and the draft angle is 0.4-0.5 degrees;
the length L of the thin-wall pipe fitting is more than or equal to 600 and less than or equal to 800mm, and the draft angle is 0.3-0.4 degrees.
3. The large-wall-thickness ceramic-based composite pipe fitting according to claim 2, wherein:
the relation between the total wall thickness t of the core thin-wall pipe (10), the middle thin-wall pipe (11) and the outermost thin-wall pipe (12) and the number n of the thin-wall pipes is as follows:
n＝t/6+1。
4. a large wall thickness ceramic matrix composite pipe according to claim 3, wherein:
the width of the groove (100) is 3-4 mm;
the mass ratio of the silicon carbide powder to the water is 5: 11.
5. a large wall thickness ceramic matrix composite pipe according to any one of claims 1 to 4, wherein:
each of the grooves (100) is formed by machining a plane extending in the axial direction on the outer surface of the core thin-walled tube member (10) or the intermediate thin-walled tube member (11).
6. A method for preparing a ceramic matrix composite pipe with large wall thickness according to any one of claims 1 to 5, characterized by comprising the following steps:
1) preparing a plurality of fiber cloth layers of carbon cloth or silicon carbide cloth with different sizes, and preparing an interface layer;
2) shaping the prefabricated body;
2.1) shaping the core thin-wall pipe prefabricated body;
winding a corresponding fiber cloth layer prepared by an interface layer on a die of the core thin-wall pipe (10), and sewing to ensure that the reserved machining allowance of the inner profile of the core thin-wall pipe preform is 0.5-1 mm, and the reserved machining allowance of the outer profile of the core thin-wall pipe preform is 0.5-1 mm, so as to obtain the core thin-wall pipe preform with the required thickness;
2.2) shaping the thin-wall pipe fitting preform at the outermost layer;
winding a corresponding fiber cloth layer prepared by the interface layer on a die of the outermost thin-wall pipe (12), and sewing to ensure that the reserved machining allowance of the inner profile of the outermost thin-wall pipe preform is 0.5-1 mm, and the reserved machining allowance of the outer profile of the outermost thin-wall pipe preform is 0.5-1 mm, so as to obtain the outermost thin-wall pipe preform with the required thickness;
2.3) shaping n-2 intermediate thin-wall pipe prefabricated bodies;
winding the corresponding fiber cloth layers prepared by the interface layer on a die of each middle thin-wall pipe fitting (11) respectively, and sewing to ensure that the reserved machining allowance of the inner profile of the middle thin-wall pipe fitting preform is 0.5-1 mm, and the reserved machining allowance of the outer profile of the middle thin-wall pipe fitting preform is 0.5-1 mm, so as to obtain n-2 middle thin-wall pipe fitting preforms;
3) respectively densifying the core thin-wall pipe preform, the n-2 middle thin-wall pipe preforms and the outermost thin-wall pipe preform by a chemical vapor deposition process to respectively obtain 1.80g/cm 3 ～2.0g/cm 3 The core thin-wall pipe fitting preform, the n-2 middle thin-wall pipe fitting preforms and the outermost thin-wall pipe fitting preform;
4) thin-wall pipe fitting processing
4.1) respectively processing the outer molded surface of the core thin-wall pipe fitting preform, the inner molded surface of the outermost thin-wall pipe fitting preform and the inner molded surface and the outer molded surface of n-2 middle thin-wall pipe fitting preforms to meet the design requirements, and simultaneously ensuring that the tolerance of the outer conical surface of each thin-wall pipe fitting is-0.10 to-0.05 mm and the tolerance of the inner conical surface is +0.05 to +0.10 mm;
4.2) respectively processing grooves on the outer molded surfaces of the core thin-wall pipe prefabricated body and the middle thin-wall pipe prefabricated body to obtain a core thin-wall pipe prefabricated body and n-2 middle thin-wall pipes (11);
5) nested assembly
5.1) nesting and assembling the core thin-wall pipe fitting prefabricated body, n-2 middle thin-wall pipe fittings (11) and the outermost thin-wall pipe fitting prefabricated body, and arranging the grooves (100) on the adjacent thin-wall pipe fittings in a staggered manner to obtain a crude product of the composite pipe fitting;
5.2) cleaning and drying the crude product of the composite pipe fitting;
5.3) filling dense liquid of silicon carbide powder and water into a gap (2) formed by the groove (100) on the thin-wall pipe fitting and the adjacent thin-wall pipe fitting for sealing and filling; the mass ratio of the silicon carbide powder to the water is 4.5-5.5: 10-12;
6) carrying out silicon carbide matrix deposition on the crude product of the composite pipe fitting;
7) superfinishing the inner and outer molded surfaces and the axial dimension of the crude product of the composite pipe fitting after the silicon carbide substrate is deposited, and ensuring that the tolerance of the inner diameter is +0.10 to +0.15mm, the tolerance of the outer diameter is-0.15 to-0.10 mm, and the tolerance of the length is 0 to 0.15 mm;
8) and (3) preparing the high-temperature-resistant silicon carbide coating on the crude product of the composite pipe fitting by a chemical vapor phase process to obtain the ceramic-based composite pipe fitting (1) with large wall thickness.
7. The method for preparing the ceramic matrix composite pipe fitting with the large wall thickness according to claim 6, wherein the method comprises the following steps:
in the step 1), the preparation process of the interface layer comprises the following steps: the deposition temperature is 650-750 ℃, the deposition time is 40-50 h, and the gas and flow are respectively 6-9L/min of propylene and 3-4L/min of argon; the vacuum degree is less than 1000 Pa.
8. The method for preparing the ceramic matrix composite pipe fitting with the large wall thickness according to claim 7, wherein the method comprises the following steps:
in the step 3), the chemical vapor deposition process comprises the following steps: the deposition time is 40-45 h, the deposition temperature is 850-1000 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.3L/min-0.35L/min, the hydrogen flow is 0.40 +/-0.2L/min, and the trichloromethylsilane flow is 0.35 +/-0.2L/min.
9. The method for preparing the ceramic matrix composite pipe fitting with the large wall thickness according to claim 8, wherein the method comprises the following steps:
in the step 6), the silicon carbide substrate deposition process comprises the following steps: the deposition time is 50-55 h, the deposition temperature is 850-1000 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.35L/min-0.4L/min, the hydrogen flow is 0.45 +/-0.2L/min, and the trichloromethylsilane flow is 0.4 +/-0.2L/min.
10. The method for preparing the ceramic-based composite pipe fitting with the large wall thickness according to claim 9, wherein the method comprises the following steps:
in the step 8), the preparation process of the high-temperature resistant silicon carbide coating comprises the following steps: the deposition time is 30-35 h, the deposition temperature is 900-1000 ℃, and the reaction gas is trichloromethylsilane, argon and hydrogen; the vacuum degree is less than 1000Pa, the argon flow is 0.25L/min-0.3L/min, the hydrogen flow is 0.35 +/-0.1L/min, and the trichloromethylsilane flow is 0.3 +/-0.2L/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210750346.8A CN115111439B (en) | 2022-06-28 | 2022-06-28 | Large-wall-thickness ceramic matrix composite pipe fitting and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210750346.8A CN115111439B (en) | 2022-06-28 | 2022-06-28 | Large-wall-thickness ceramic matrix composite pipe fitting and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115111439A true CN115111439A (en) | 2022-09-27 |
| CN115111439B CN115111439B (en) | 2024-03-08 |
Family
ID=83331034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210750346.8A Active CN115111439B (en) | 2022-06-28 | 2022-06-28 | Large-wall-thickness ceramic matrix composite pipe fitting and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115111439B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1287989A (en) * | 2000-10-27 | 2001-03-21 | 中国科学院上海硅酸盐研究所 | Method for mfg. high strength, screen like and porous ceramic |
| CN101087739A (en) * | 2004-12-23 | 2007-12-12 | 马塞尔-布加蒂股份有限公司 | A method of making a fiber preform for manufacturing parts of a composite material of the carbon/carbon type incorporating ceramic particles, and products obtained thereby |
| CN102764841A (en) * | 2012-07-19 | 2012-11-07 | 西北工业大学 | Core mold and shaping method for shaping strip annular internal reinforced rib rotary body thin-wall part |
| CN102933334A (en) * | 2010-06-04 | 2013-02-13 | 住友电气工业株式会社 | Composite material, component for continuous casting, nozzle for continuous casting, continuous casting method, cast material, and magnesium alloy cast coil material |
| US20160107940A1 (en) * | 2013-03-15 | 2016-04-21 | Rolls-Royce Corporation | Ceramic matrix composites and methods for producing ceramic matrix composites |
| CN108691584A (en) * | 2017-04-07 | 2018-10-23 | 通用电气公司 | It is used to form the method and sub-assembly of the feature in composite component |
| CN210440706U (en) * | 2019-08-09 | 2020-05-01 | 湖州祥瑞机械科技有限公司 | High-strength fiber composite pulling and winding glass fiber reinforced plastic pipeline |
| CN112476874A (en) * | 2020-11-04 | 2021-03-12 | 西安鑫垚陶瓷复合材料有限公司 | S-shaped structural member mold and method for preparing S-shaped structural member by using same |
| CN114057502A (en) * | 2021-11-25 | 2022-02-18 | 西安鑫垚陶瓷复合材料有限公司 | Preparation method of ceramic matrix composite material slender thin-wall pipe fitting, ceramic matrix composite material slender thin-wall pipe fitting based on preparation method and application |
| US20220055957A1 (en) * | 2020-08-19 | 2022-02-24 | Rolls-Royce High Temperature Composites Inc. | Method of making a ceramic matrix composite that exhibits chemical resistance |
-
2022
- 2022-06-28 CN CN202210750346.8A patent/CN115111439B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1287989A (en) * | 2000-10-27 | 2001-03-21 | 中国科学院上海硅酸盐研究所 | Method for mfg. high strength, screen like and porous ceramic |
| CN101087739A (en) * | 2004-12-23 | 2007-12-12 | 马塞尔-布加蒂股份有限公司 | A method of making a fiber preform for manufacturing parts of a composite material of the carbon/carbon type incorporating ceramic particles, and products obtained thereby |
| CN102933334A (en) * | 2010-06-04 | 2013-02-13 | 住友电气工业株式会社 | Composite material, component for continuous casting, nozzle for continuous casting, continuous casting method, cast material, and magnesium alloy cast coil material |
| CN102764841A (en) * | 2012-07-19 | 2012-11-07 | 西北工业大学 | Core mold and shaping method for shaping strip annular internal reinforced rib rotary body thin-wall part |
| US20160107940A1 (en) * | 2013-03-15 | 2016-04-21 | Rolls-Royce Corporation | Ceramic matrix composites and methods for producing ceramic matrix composites |
| CN108691584A (en) * | 2017-04-07 | 2018-10-23 | 通用电气公司 | It is used to form the method and sub-assembly of the feature in composite component |
| CN210440706U (en) * | 2019-08-09 | 2020-05-01 | 湖州祥瑞机械科技有限公司 | High-strength fiber composite pulling and winding glass fiber reinforced plastic pipeline |
| US20220055957A1 (en) * | 2020-08-19 | 2022-02-24 | Rolls-Royce High Temperature Composites Inc. | Method of making a ceramic matrix composite that exhibits chemical resistance |
| CN112476874A (en) * | 2020-11-04 | 2021-03-12 | 西安鑫垚陶瓷复合材料有限公司 | S-shaped structural member mold and method for preparing S-shaped structural member by using same |
| CN114057502A (en) * | 2021-11-25 | 2022-02-18 | 西安鑫垚陶瓷复合材料有限公司 | Preparation method of ceramic matrix composite material slender thin-wall pipe fitting, ceramic matrix composite material slender thin-wall pipe fitting based on preparation method and application |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115111439B (en) | 2024-03-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4519290A (en) | Braided preform for refractory articles and method of making | |
| CN106967963A (en) | Silicon or carborundum gas ejector for lining treatment system | |
| JP2003128471A (en) | Method for producing melt-inpregnated ceramic composite using forming support | |
| US6216585B1 (en) | Carbon-carbon engine components and method of fabrication | |
| FR3071245B1 (en) | METHOD FOR INJECTING A BARBOTIN CHARGED WITH FIBROUS TEXTURE | |
| EP3551593A1 (en) | Shaping equipment and facility for gas-phase chemical infiltration of fibrous preforms | |
| WO2015077020A1 (en) | Apparatus and method for skinning articles | |
| CN111875401B (en) | Preparation method of high-strength and high-purity carbon/carbon composite material revolving body formed by winding | |
| CN115231938A (en) | Preparation method of carbon/carbon composite material brake disc | |
| CN115111439B (en) | Large-wall-thickness ceramic matrix composite pipe fitting and preparation method thereof | |
| CN111302820B (en) | Preparation method of C/SiC composite material | |
| CN113233910A (en) | Method for improving densification density of thick carbon/carbon composite material plate | |
| US6085714A (en) | Carbon--carbon composite valve for high performance internal combustion engines | |
| KR20190035933A (en) | Process for manufacturing SiC composite ceramics | |
| CN217997314U (en) | Chemical vapor infiltration device for producing carbon/carbon thermal field material | |
| CN112457027A (en) | Large-size circular-section ceramic matrix composite component melting siliconizing tool and method | |
| FR3042188A1 (en) | PROCESS FOR PRODUCING IMPREGNATED FIBROUS ASSEMBLY | |
| EP3592716A1 (en) | Method for producing a consolidated fibrous preform | |
| US20010035592A1 (en) | Combination continuous woven-fiber and discontinuous ceramic-fiber structure | |
| CN215713361U (en) | Tool for chemical vapor infiltration method | |
| CN112981371B (en) | Chemical vapor deposition mould | |
| CN114810820B (en) | Special-shaped bearing with integrated structure based on ceramic matrix composite and preparation method thereof | |
| CN114835500B (en) | Preparation method of variable-curvature reinforced member made of SiC/SiC composite material | |
| CN113845370B (en) | Variable-density carbon/carbon composite material heat-insulating barrel and preparation method thereof | |
| WO2014170586A1 (en) | Holding and loading tool and facility for densifying porous rotating preforms |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Country or region after: China Address after: 710117 West Section 912 of Biyuan Road, Xi'an High-tech Zone, Shaanxi Province Applicant after: Xi'an Xinyao Ceramic Composite Co.,Ltd. Address before: 710117 West Section 912 of Biyuan Road, Xi'an High-tech Zone, Shaanxi Province Applicant before: XI'AN GOLDEN MOUNTAIN CERAMIC COMPOSITES CO.,LTD. Country or region before: China |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |