阅读说明：本技术 一种三维机织航空火焰筒及其制备方法 (Three-dimensional woven aviation flame tube and preparation method thereof ) 是由 周婵颖 伍立立 宗晟 于 2020-06-19 设计创作，主要内容包括：本发明公开了一种三维机织航空火焰筒及其制备方法,包括：根据2.5D立体机织结构设计,利用变截面一体化编织工艺进行2.5D SiC纤维预制体的制备；以液态聚碳硅烷为先驱体,对SiC纤维预制体进行先驱体浸渍热裂解工艺,制备得到SiCf/SiC火焰筒；采用大气等离子喷涂工艺在SiCf/SiC火焰筒的表面制备环境障碍涂层,得到最终的三维机织航空火焰筒。本发明制备得到的三维机织航空火焰筒具有质量轻、强力高、耐高温、耐腐蚀以及较好的抗压、抗氧化、抗热冲击等综合效能,且结构稳定性能良好,大大提高了航空用火焰筒在高温下的适应性。(The invention discloses a three-dimensional woven aviation flame tube and a preparation method thereof, wherein the preparation method comprises the following steps: preparing a 2.5D SiC fiber preform by utilizing a variable cross-section integrated weaving process according to the 2.5D three-dimensional weaving structure design; taking liquid polycarbosilane as a precursor, and carrying out a precursor impregnation thermal cracking process on the SiC fiber preform to prepare a SiCf/SiC flame tube; and preparing an environmental barrier coating on the surface of the SiCf/SiC flame tube by adopting an atmospheric plasma spraying process to obtain the final three-dimensional woven aviation flame tube. The three-dimensional woven aviation flame tube prepared by the invention has the comprehensive effects of light weight, high strength, high temperature resistance, corrosion resistance, better compression resistance, oxidation resistance, thermal shock resistance and the like, has good structural stability and greatly improves the adaptability of the aviation flame tube at high temperature.)

1. The preparation method of the three-dimensional woven aviation flame tube is characterized by comprising the following steps of:

(1) determining the specific shape and size of a flame tube according to equipment of an aviation combustion chamber, and designing a 2.5D three-dimensional weaving structure, including the design of the warp density and the weft density of the used SiC fibers;

(2) preparing a 2.5D SiC fiber preform on a three-dimensional textile machine by utilizing a variable cross-section integrated weaving process according to the 2.5D three-dimensional weaving structure design;

(3) taking liquid polycarbosilane as a precursor, and carrying out a precursor impregnation thermal cracking process on the SiC fiber preform to prepare a SiCf/SiC flame tube;

(4) and (3) taking the SiCf/SiC flame tube as a substrate material, and preparing an environmental barrier coating on the surface of the substrate material by adopting an atmospheric plasma spraying process to obtain the final three-dimensional woven aviation flame tube.

2. The preparation method according to claim 1, wherein the step (3) specifically comprises:

preparing a PyC interface layer on the surface of the SiC fiber preform by a chemical vapor deposition process, wherein the thickness of the interface layer is controlled to be 0.1-0.3 mm; and then, taking liquid polycarbosilane as a precursor, carrying out PIP (Poly propylene glycol) process to prepare the SiCf/SiC flame tube, wherein the dipping-cracking cycle is 8-15 times until the cracking weight gain rate is less than 2%.

3. The manufacturing method according to claim 1, wherein in the step (2), the variable cross-section integrated knitting process is realized by controlling knitting paths and yarn changes.

4. The production method according to claim 1, wherein in the step (2), the SiC fiber preform is woven by using second-generation SiC fibers.

5. The production method according to claim 1, wherein in the step (2), the fiber volume content of the SiC fiber preform is 40% to 55%.

6. The preparation method according to claim 1, wherein in the step (4), the environmental barrier coating is a mullite/rare earth silicate coating, Ar is used as a main gas and a carrier gas, He is used as an auxiliary gas, powder is fed in an internal powder feeding mode, the sample needs to be preheated once before the first spraying, and after each coating is sprayed, air cooling is adopted.

7. A three-dimensional woven aviation flame tube made according to the method of any of claims 1-6.

Technical Field

The invention relates to a three-dimensional woven aviation flame tube and a preparation method thereof, and belongs to the technical field of aviation engine combustion chambers.

Background

The combustion chamber of the aircraft engine undertakes the task of converting the chemical energy of the fuel into heat energy, the main task is to generate a high-temperature combustion gas device in the fuel or propellant, which is one of the core components of the aircraft engine, and under the high-temperature service condition, the combustion chamber of the aircraft engine needs to have extremely high stability and faces extremely harsh service environment. The combustion chamber mainly comprises a diffuser, a combustion chamber shell, a flame tube, a fuel nozzle and an ignition device. The flame tube is a combustion place in a combustion chamber of an aircraft engine and is a part which ensures air to be stranded, fully combusted and uniformly mixed and enables the wall surface to be effectively cooled. The flame tube mainly comprises a tube body and a swirler at the head of the flame tube. The traditional alloy flame tube body is in a high-temperature environment for a long time, the working environment is severer, the yield stress or the lasting strength of the material is reduced after the alloy flame tube body works for a long time, and meanwhile, the working life is greatly reduced under the direct influence of cold and hot fatigue, gas oxidation corrosion, scouring, abrasion and the like. The service life of the flame tube is directly related to the service life of the combustion engine, and in order to improve the service life of the flame tube and ensure the stability of the flame tube in a service environment, the flame tube body not only needs to adapt to light weight, but also can ensure high oxidation resistance and corrosion resistance, so that the problem that the development of the flame tube body with high strength, corrosion resistance and good stability is urgently needed to be solved at present.

The flame tube prepared from the composite material has the advantages of light weight, strong designability and the like, and the silicon carbide fiber reinforced silicon carbide matrix (SiCf/SiC) composite material has excellent performances of high specific strength, high specific modulus, high temperature resistance, creep resistance, corrosion resistance, wear resistance, oxidation resistance and the like, effectively overcomes the defects of high brittleness, low fracture toughness and poor impact resistance of pure ceramic fiber, and is an ideal candidate material for hot-end high-temperature components such as an aircraft engine combustor/afterburner, a turbine guide vane, an inner duct, a tail nozzle and the like.

In order to ensure that the flame tube has the characteristics of high interlayer connection strength and good integrity, the invention combines a 2.5D variable cross-section integrated weaving technology with a precursor impregnation thermal cracking (PIP) technology and is matched with an environmental barrier coating to realize the integral forming of the three-dimensional woven flame tube. The variable cross-section integrated technology can effectively improve the overall stability of the flame tube, the composite molding precursor impregnation thermal cracking (PIP) technology is suitable for preparing structures with large size and complex shape, the microstructure is controllable, the cost is low, and the environmental barrier coating further enhances the durability of the material. The three are effectively combined, and the durability of the flame tube is fully improved.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects in the prior art, the invention provides the three-dimensional woven aviation flame tube and the preparation method thereof, which adopt the structural design of three-dimensional woven variable cross-section integrated molding and the preparation method of precursor impregnation thermal cracking technology (PIP) to meet the requirements of high temperature resistance, oxidation resistance and good stability of the aviation flame tube.

The technical scheme is as follows: in order to achieve the purpose, the invention adopts the technical scheme that:

a preparation method of a three-dimensional woven aviation flame tube comprises the following steps:

(1) determining the specific shape and size of a flame tube according to equipment of an aviation combustion chamber, and designing a 2.5D three-dimensional weaving structure, wherein the design comprises the design of parameters such as the warp density and the weft density of used SiC fibers;

(2) preparing a 2.5D SiC fiber preform on a three-dimensional textile machine by utilizing a variable cross-section integrated weaving process according to the 2.5D three-dimensional weaving structure design;

(3) taking liquid polycarbosilane as a precursor, and carrying out a precursor impregnation thermal cracking (PIP) process on the SiC fiber preform to prepare a SiCf/SiC flame tube;

(4) and (3) taking the SiCf/SiC flame tube as a substrate material, and preparing an environmental barrier coating on the surface of the substrate material by adopting an atmospheric plasma spraying process to obtain the final three-dimensional woven aviation flame tube.

Further, the step (3) specifically includes:

preparing a PyC interface layer on the surface of the SiC fiber preform by a Chemical Vapor Deposition (CVD) process, wherein the thickness of the interface layer is controlled to be about 0.2 mm; and then, liquid Polycarbosilane (PCS) is used as a precursor, a PIP process is carried out to prepare the SiCf/SiC flame tube, and the dipping-cracking cycle is 8-15 times until the cracking weight gain rate is less than 2%.

Further, in the step (2), the variable cross-section integrated knitting process is mainly realized by controlling knitting paths and yarn changes.

Further, in the step (2), the SiC fiber preform is woven by using a second-generation SiC fiber (trademark, canas 3200).

Further, in the step (2), the fiber volume content of the SiC fiber preform is 40% -55%.

Further, in the step (4), the environmental barrier coating is Mullite/rare earth silicate (Mullite/Sc)₂Si₂O₇+Sc₂O₃) And each layer of the coating is about 100 mu m thick, Ar is used as main gas and carrier gas, He is used as auxiliary gas, powder is fed in an internal powder feeding mode, a sample needs to be preheated once before the first spraying, and air cooling is adopted after the spraying of each layer of the coating is finished.

The three-dimensional woven aviation flame tube prepared by the method comprises a three-dimensional woven SiC fiber preform, and is impregnated, thermally cracked and deposited on the SiC fiber preform by using a composite process to form silicon carbide reinforced silicon carbide (SiC)_fSiC) aircraft flame tube; the three-dimensional woven SiC fiber preform structure is prepared by a special 2.5D method in three-dimensional weaving, namely, the 2.5D SiC preform is prepared by a variable cross-section integrated braiding technology. The 2.5D machine weaving has the characteristics of better integrity, one-step forming, stronger shearing performance, structure designability and the like, and is suitable for preparing complex components such as a flame tube and the like.

Has the advantages that: compared with the prior art, the three-dimensional woven aviation flame tube and the preparation method thereof provided by the invention have the following advantages: 1. according to the size requirement of the aviation flame tube, SiC fiber three-dimensional woven forming preforms with different shapes and sizes are designed, and the flame tube preforms are designed in a targeted manner through SiC yarn type combination and yarn arrangement direction combination.

2. The preparation of the SiC fiber preform is completed at one time by utilizing the variable cross-section and variable density braiding technology, a three-dimensional woven structure can be braided and formed according to the load conditions of different parts of the flame tube, and the production efficiency is high.

3. Liquid polycarbosilane is used as a precursor to prepare SiC by (PIP)_fA flame tube of SiC or SiC_fThe SiC flame tube is used as a substrate material, and an environment barrier coating is prepared on the surface of the flame tube by adopting an atmospheric plasma spraying process to prepare SiC with good durability, corrosion resistance and high temperature resistance_fA SiC flame tube.

Drawings

FIG. 1 is a schematic structural diagram of a three-dimensional woven aviation flame tube of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and examples.