1031 results about "Ceramic matrix composite" patented technology

The invention discloses an intelligent segmentation method and device for ceramic matrix composite CT image defects, and belongs to the technical field of image detection. The method comprises the following steps: inputting preprocessed CT image data into a preset double-branch collaborative segmentation model, and respectively outputting to obtain a local texture feature map and a global relation feature map; performing three-branch material perception fusion processing on the local texture feature map and the global relation feature map according to a preset perception fusion model to obtain a fusion feature map containing local detail accuracy and global consistency; sequentially carrying out progressive decoding and refined reconstruction processing on the fused feature graph to obtain a defect probability graph; and calculating a loss function of the defect probability graph and a manually pre-labeled real defect segmentation graph, and dynamically adjusting the loss weight of the initial model according to a calculation result to obtain a CT image defect segmentation model meeting a preset convergence condition. The method can meet the detection requirements of industrial scenes on the defects of the ceramic-based composite material.

The invention belongs to the field of aero-engines, relates to an engine main combustion chamber design technology, and provides a ceramic matrix composite material flame tube matching design method and system.The method comprises the steps that a flame tube wall temperature interval of a main working state point is obtained; determining the thermal-state radial dimensions of the feature points on the ceramic-based component and the metal component; converting the hot-state radial size into a cold-state radial size; carrying out two-dimensional cold-state flame tube profile design; and the cold-state radial size of the two-dimensional cold-state flame tube molded surface is converted into the hot-state size to obtain a two-dimensional hot-state flame tube molded surface, and a three-dimensional hot-state model is constructed and evaluated and iteratively optimized. According to the method, matching structure characteristic parameters of the ceramic-based component and the metal component are designed, and the molded surface of the flame tube made of the different materials is self-adaptively formed into smooth transition at main working state points, so that a backflow area is actively controlled, and the problems that the stability of a flow field of a main combustion chamber is influenced and pressure is lost due to different and relative displacement changes in the working process are solved.

A method of forming a ceramic matrix composite component includes forming a fiber preform, the fiber preform including a plurality of ceramic fiber plies, a non-reduced fiber region having an areal weight, and a reduced fiber region characterized by a reduced areal weight less than the areal weight of the non-reduced fiber region by at least 5 percent. The method further includes selectively applying ceramic particles to the reduced fiber region in such manner as to avoid applying the ceramic particles to the non-reduced fiber region, and subsequently densifying the preform.

The invention discloses a silicon nitride ceramic-based composite material and a preparation method thereof, and relates to the technical field of silicon nitride ceramics. The silicon nitride ceramic-based composite material is prepared from silicon dioxide coated modified boron nitride and resin composite phase change microcapsules, Si3N4-C coated Al2O3 core-shell fiber aerogel, nano yttrium oxide and polyvinyl butyral, the silicon dioxide coated modified boron nitride and resin composite phase change microcapsules are stably attached to the surface of the Si3N4-C coated Al2O3 core-shell fiber aerogel in a chemical bonding and mechanical interlocking mode, the interface bonding strength is enhanced, the risk of phase separation is reduced, the combination effect of the silicon dioxide coated modified boron nitride and resin composite phase change microcapsules and the Si3N4-C coated Al2O3 core-shell fiber aerogel is better exerted, and the composite phase change effect of the silicon dioxide coated modified boron nitride and resin composite phase change microcapsules is improved. According to the present invention, the fracture toughness can be improved through fiber toughening, aerogel pore and microcapsule stress dispersion, the high temperature resistance can be improved through the low thermal conductivity of the aerogel and the heat absorption effect of the microcapsule, the mechanical property of the silicon nitride can be significantly improved through multiple ways and multiple modes, and the high temperature resistance can be effectively enhanced.

The invention discloses a method for testing interlayer tensile strength of a ceramic matrix composite material. Comprising the following steps: acquiring the geometric dimension of a sample, performing surface treatment on a test surface of the sample, marking a test section of the sample, acquiring the geometric dimension of a four-point bending clamp, determining a placement mode of the sample and a camera, and capturing a displacement field of the test surface of the sample by using the camera while performing a curved beam four-point bending test. Obtaining the load value and stroke of the first load drop, extracting the in-situ strain of the sample by using a camera, deducing a formula for calculating the interlayer radial and tangential modulus ratio of the sample, carrying out calculation, and calculating the interlayer tensile strength of the sample by using the existing formula. According to the method disclosed by the invention, the modulus ratio of the interlayer radial direction to the interlayer tangential direction is obtained by using in-situ strain, the problem that the interlayer radial modulus is difficult to accurately determine directly through the test is solved, and the accuracy of the interlayer tensile strength of the ceramic matrix composite material measured through the curved beam four-point bending test is improved.

The invention relates to the technical field of aero-engine part machining, in particular to a machining method for a ceramic matrix composite turbine outer ring. The method specifically comprises the following steps: polishing a blank; blank detection; cutting the silicon shell; trimming is conducted; bonding is conducted; milling is conducted; repairing and cleaning by pincers; and inspecting. According to the method, a bonding clamping mode is adopted, a traditional pressing plate and bolt pressing structure is omitted, the structure of a tool clamp is simplified, the operation complexity of the clamp is reduced, and large machining and tool cost is saved; after the blank benchmark of the part is determined, the part is directly machined to the final size at a time, benchmark conversion is not needed, machining errors caused by clamping and benchmark conversion are reduced, the size precision and stability are guaranteed, and meanwhile the production efficiency is improved.

The invention discloses a morphology reconstruction method for a deposition layer of a ceramic matrix composite air film cooling structure, and belongs to the field of engineering thermophysics. According to the method, on the basis of traditional fluid-solid coupling heat transfer simulation, a track of dust particles on the surface of the ceramic-based composite material air film cooling structure is simulated in combination with a dispersed phase model, deposition layer thickness distribution characteristics are obtained, and after coordinate positions and normal vectors on surface grids are obtained through a user-defined function, the deposition layer thickness distribution characteristics are obtained. And directionally moving the coordinates at different positions of the component along the normal direction by the distance of the deposition thickness to obtain coordinate values of the surface of the sediment, and sequentially reconstructing the obtained coordinate point clouds into a polygonal mesh surface and a geometric model to obtain the geometric morphology of the reconstructed deposition layer. Therefore, the comprehensive cooling efficiency and attenuation characteristics of the ceramic-based composite material air film cooling structure under the influence of the deposited particles can be accurately calculated by simulating and analyzing the influence of the deposited layer on parameters such as flow characteristics and temperature distribution on the wall surface.

The invention discloses direct writing forming equipment and method for a continuous fiber reinforced ceramic matrix composite, the direct writing forming equipment comprises an XYZ-axis motion platform, an extrusion nozzle, an ultrasonic transducer, a screw propeller, a wire feeder, a forming table and a curing mechanism, the extrusion nozzle is mounted on the XYZ-axis motion platform, and an outlet is formed in the bottom of the extrusion nozzle; the screw propeller comprises a motor and a screw, the motor is mounted on the extrusion nozzle and connected with the screw to drive the screw to rotate, so that the screw shears ceramic slurry in the extrusion nozzle and extrudes the ceramic slurry from an outlet of the extrusion nozzle, and a through hole is formed in the screw. Continuous fibers sent out by the wire feeder penetrate through the screw rod and then are discharged from an outlet of the extrusion nozzle; and the curing mechanism is used for curing the ceramic slurry on the forming table. The viscosity of the ceramic slurry is reduced through the shearing effect of the screw rod, blockage is prevented, and the extrusion nozzle can disperse nano-particle aggregates in the ceramic slurry through the vibration effect of ultrasonic waves.

The invention relates to a water jet-laser / mechanical energy field cooperative precision machining method for a ceramic base material, and belongs to the field of laser-mechanical cooperative machining. During the execution period, the method comprises the following steps in sequence: firstly, carrying out rapid and low-damage precise material reduction on the ceramic matrix composite material through water jet assisted laser; and then, a superhard forming grinding wheel on the same machine tool is matched with mixed grinding fluid to conduct in-situ finishing and polishing on the surface obtained after material reduction. Wherein the surface quality can be improved while high-efficiency machining is ensured through the synergistic combination of laser and machinery. Through the in-situ grinding and polishing effect of the grinding wheel and the mixed grinding fluid, the precision of a formed surface is higher, and a damaged layer is thinner and even completely removed. Based on a water jet assisted laser milling / mechanical grinding and polishing collaborative machining strategy, rough machining, finish machining and fine polishing of the ceramic matrix composite can be completed on the same equipment, and the method has the characteristics of being high in precision, high in efficiency, high in quality and extremely low in surface damage.

An apparatus for controlling a layer of a composite material includes a robotic arm (18) and an end effector (100) mounted on the robotic arm.The end effector (100) comprises a base (112) attached to the robotic arm (18), the base (112) comprising a base track (116) extending along a first translational dimension, a platform (114) supported by the base (112) and movable along the base track (116), the platform (114) comprising a platform track (124) extending along a second translational dimension, a disk (134) supported by the platform (114) and movable along the platform track (124), the disk (134) being rotatable about a first rotational dimension, an arcuate track (136) supported by the disk (134), the arcuate track (136) extending along a second rotational dimension, and a layer manipulator (102) extending from the arcuate track (136) and movable along the arcuate track (136).

A method for fabricating a metal-infiltrated ceramic matrix composite, comprises: providing a ceramic fiber preform comprising a fiber tow; depositing an interface coating material around the fiber tow to form an interface coating therearound, and form an interfaced coated ceramic preform containing the interface coated fiber tows; depositing a silicon carbide layer around the interface coated fiber tow; depositing a reaction-barrier coating around the interface coated, silicon carbide coated fiber tow of the interface coated, silicon carbide coated ceramic preform; infiltrating the interface coated, silicon carbide coated ceramic preform with a slurry comprising a carbon source; drying the slurry infiltrated interface coated, silicon carbide coated ceramic preform; and infiltrating the dried slurry infiltrated interface coated, silicon carbide coated ceramic preform with a molten ternary metal alloy, a molten ternary metalloid alloy, a molten ternary metal alloy comprising boron as a constituent, a molten ternary metalloid alloy comprising boron as a constituent, a ternary metal melt, a ternary metalloid melt, a ternary metal melt comprising boron as a constituent, or a ternary metalloid melt comprising boron as a constituent, combinations comprising at least one of the foregoing; to form a melt-infiltrated ceramic matrix composite.

Systems, structures, devices, and fabrication processes for ceramic matrix composites suitable for use in a nuclear reactor environment and other applications requiring materials that can withstand high temperatures and / or highly corrosive environments are disclosed. In one aspect, a ceramic composite structure is provided. The structure comprises a chamber including an external shell and a hollow space inside the external shell. The external shell includes an inner composite layer including a first composite structure, a middle composite layer placed outside of the inner composite layer, the middle composite layer including a second composite structure that is different from the first composite structure, and an outer monolithic layer that has a spatially uniform material property and placed outside of the middle composite layer.

The invention relates to a preparation method of a ceramic-based composite material, in particular to a preparation method of a ceramic-based composite material with a pyrolytic carbon-carbon nanotube interface, which is used for solving the problem that in the aspect of improving the thermal conductivity of an interface layer, metals such as Fe, Co, Ni and the like are widely used as catalysts for growing carbon nanotubes at present, so that the thermal conductivity of the interface layer is improved. Carbon nanotubes obtained through a traditional preparation method are prone to agglomeration and uneven in distribution, the risk of the preparation process is high, the carbon nanotubes are not suitable for large-scale production, although metal particles can be reduced through a chemical plating method, the particle sizes of the metal particles are not controlled, the distribution of the metal particles is uneven, and the requirement of a chemical vapor reduction method for distribution of an earlier-stage metal salt solution is high. And the defect is difficult to realize easily. According to the preparation method of the ceramic-based composite material with the pyrolytic carbon-carbon nanotube interface, the ceramic-based composite material with the pyrolytic carbon-carbon nanotube interface is finally obtained through pretreatment, solution A preparation, metal salt solution in-situ reduction and chemical vapor deposition in sequence.

A gas turbine engine component, comprises a densified three-dimensional woven ceramic matrix composite comprising the shape of the gas turbine engine component, the densified three-dimensional woven ceramic matrix composite further comprises a three-dimensional woven structure comprising a densified ceramic matrix disposed on, within and throughout a three-dimensional weave comprising at least one inorganic fiber comprising at least one multilayer coating material structure disposed thereupon, wherein the at least one multilayer coating material structure comprises at least one first interface coating material layer comprising a boron nitride; at least one coating material layer comprising a silicon nitride; at least one second interface coating material layer comprising the boron nitride; and at least one third interface coating material layer comprising a Si3N4-BN multilayer coating having one or more alternating layers comprising at least one layer of silicon nitride at a first thickness; and at least one layer of boron nitride at a second thickness.

The invention provides a preparation method of an ultrahigh-temperature ceramic-based composite material with a layered structure, and relates to the technical field of ceramic-based composite materials. The method specifically comprises the steps that a PyC interface is deposited on the surface of a porous prefabricated body, then a SiC matrix and a PyC matrix are sequentially deposited on the surface of the PyC interface, then the porous prefabricated body is placed in molten salt powder containing metal powder and chlorine salt powder to be subjected to embedding treatment, then a carbon source is introduced, alloy powder serves as a raw material, reaction melt infiltration treatment is conducted on the carbon composite material, and the SiC / PyC composite material is obtained. The superhigh-temperature ceramic matrix composite material with the layered structure is obtained. Compared with the prior art, the preparation method has the advantages that molten salt is used as assistance, the ultra-high-temperature ceramic layered matrix is prepared on the semi-compact C / SiC composite material by adopting an embedding method, and finally, the densification of the composite material is realized by using a reaction melt infiltration process, so that the problem that the mechanical property of the ultra-high-temperature ceramic matrix composite material is poor due to the fact that carbon fibers are damaged by an existing RMI process is solved.

We provide a coating as an environmental barrier coating, for example on a ceramic matrix composite, e.g., in a gas turbine. The coating comprises a rare earth monosilicate and a rare earth disilicate in a weight ratio of at least about 70:30. The coating is at least 60% crystalline, has a porosity of at most about 40%, and is free of through-thickness cracks. We also provide a method of manufacturing this coating comprising heating a substrate to at least about 500° C., and depositing the coating by atmospheric plasma spraying ytterbium disilicate particles on the heated substrate, wherein the atmospheric plasma spraying is performed with a plasma spray torch operated at an operating power of at least 60 kW.

The invention provides a thermal analysis method and system for a ceramic matrix composite high-pressure turbine blade. The method comprises the steps that S1, a grid is generated based on a turbine blade profile; s2, calculating and assigning a heat conductivity coefficient tensor according to the generated grid; the heat conductivity coefficient tensor comprises the heat conductivity coefficient tensor of the blade surface, the heat conductivity coefficient tensor of the interior of the blade body and the heat conductivity coefficient tensor of the rib plate; and S3, carrying out heat conductivity coefficient tensor assignment, carrying out final heat conduction or gas-solid-heat coupling calculation, and outputting a calculation result. According to the invention, a set of assignment method for the anisotropic heat conductivity coefficient of the CMC material is established, an automatic assignment system for the anisotropic heat conductivity coefficient is established by adopting MATLAB and Fluent UDF, the problem of rapid assignment of the anisotropic heat conductivity coefficient of the CMC high-pressure turbine guide vane is solved, and technical support is provided for coupling thermal analysis and research of the CMC high-pressure turbine guide vane.

The invention belongs to the technical field of ceramic materials, and particularly discloses whisker toughened zirconium oxide-aluminum oxide composite ceramic and an additive manufacturing method thereof, the composite ceramic comprises the following components by mass: 94 parts of zirconium oxide toughened aluminum oxide ceramic and 5 parts of silicon carbide whisker; the zirconium oxide toughened aluminum oxide ceramic is prepared from the following components in parts by mass: 76 parts of aluminum oxide and 24 parts of zirconium oxide, and 3mol% of yttrium oxide is added into the zirconium oxide. According to the whisker toughened zirconium oxide-aluminum oxide composite ceramic and the additive manufacturing method thereof, the preparation method has unique design of components and process, and the preparation of a high-density and high-performance ceramic-based composite material part based on a fused deposition modeling technology is successfully realized. Further, the prepared silicon carbide whisker toughened zirconium oxide-aluminum oxide-based composite ceramic has relatively high density and excellent obdurability.

A cooling flow arrangement for a ceramic matrix composite (CMC) component of a turbine engine, wherein the CMC component includes a hot side configured for exposure to a hot gas path of the turbine engine and an opposing cold side. At least one cavity is provided in the CMC component, the at least one cavity having an entrance disposed on the cold side that is configured for receiving a cooling flow. A seal is disposed adjacent the at least one cavity and the cold side of the CMC component and is configured to provide a seal between the CMC component and an upstream turbine component. At least one hole extends through the seal and is positioned to provide the cooling flow to the at least one cavity of the CMC component.

The invention discloses a single-stroke breakpoint-free path planning method for a 3D printing variable-wall-thickness honeycomb structure, and the method comprises the following steps: determining the stress distribution condition of an equal-wall-thickness honeycomb structure continuous carbon fiber reinforced silicon carbide ceramic-based composite material through software simulation, and determining a weakest region and a weakest region; variable-wall-thickness honeycomb printing is arranged in the weakest area and the weaker area; the side length and the offset distance of the honeycomb unit are determined, and a 3D printing path is set, specifically, the odd-number-layer path is different from the even-number-layer path, the outer contours of the honeycomb unit are sequentially printed in the vertical direction through the odd-number-layer path, the honeycomb unit does not completely pass through each honeycomb wall of the honeycomb structure, and the honeycomb structure is not completely formed after printing is completed; and when the next even-numbered layer is printed, missing honeycomb walls of the upper odd-numbered layer are passed twice, so that the missing honeycomb walls are complemented, and a complete variable-wall-thickness honeycomb structure is formed. According to the method, weak spots are effectively strengthened in a targeted mode, the material is not prone to damage, and the mechanical property is remarkably improved.

A combustor for a gas turbine engine includes a ceramic matrix composite (CMC) dome structure, a CMC outer liner, a CMC inner liner, and a cowl structure, that are connected together via at least one outer connection and at least one inner connection. An outer seal member is arranged to seal an outer gap between an outer liner connecting flange and an outer dome connecting flange, and an inner seal member is arranged to seal an inner gap between an inner liner connecting flange and an inner dome connecting flange.

The invention discloses a method for determining interlayer tensile strength of a ceramic matrix composite based on a three-point bending test. The method comprises the following steps: acquiring the geometric dimension of an original sample and determining the carbon fiber trend of the original sample; treating and bonding the bonding surface of the original sample to obtain a to-be-tested sample; the geometric dimension of the three-point bending clamp is obtained, and the placement mode of the to-be-tested sample is determined; a standard three-point bending test is carried out, and the maximum loading force in the test process is obtained; and calculating the breaking strength of the to-be-tested sample by using a three-point bending stress formula. A to-be-tested sample is prepared by bonding a plurality of original samples, a standard three-point bending test is carried out by using the to-be-tested sample, and finally, the interlayer tensile strength of the original samples is calculated by using a three-point bending beam stress expression, so that the problems that a test sample is difficult to prepare and a test result is inaccurate in an existing standard test method are solved; the efficiency and the precision of measuring the interlayer tensile strength of the ceramic matrix composite material are improved.

The invention relates to a low-expansion, ablation-resistant and heat-insulating integrated composite material and a preparation method thereof, and belongs to the field of ceramic-based composite materials. Comprising the following steps: putting a fiber reinforcement into a high-temperature furnace, and carrying out glue removal treatment in a vacuum state to remove a surface glue layer; adding low-expansion ceramic powder and ultrahigh-temperature ceramic powder into the ceramic precursor, and carrying out ball milling and uniform mixing to obtain a mixed solution; introducing the mixed solution into the central area of the fiber preform by adopting an injection mode, soaking the fiber preform in the mixed solution, soaking the mixed solution into the fiber preform by adopting a vacuum impregnation and pressure impregnation mode, and fully impregnating, compounding and curing; and putting the cured green body into a high-temperature atmosphere furnace for cracking, and obtaining composite materials with different densities by controlling the number of times of impregnation and cracking. The prepared composite material has excellent heat insulation, ablation resistance and bearing performance, has more reliable thermal stability and reliability, is simple in process and short in period, and can be applied to the fields of ultra-high-speed aircrafts and the like.

The invention belongs to the technical field of grinding materials and grinding tools, and particularly relates to a diamond electroplated grinding wheel directionally arranged in a magnetic field and a preparation method and application thereof. Firstly, electroplating liquid is added into an electroplating bath, then 30%-40% of magnetic diamond abrasive materials are added into the electroplating liquid, directional magnetic sanding is carried out with the grinding wheel base body A as a cathode and a nickel plate as an anode, the magnetic field intensity is controlled to be 0.1-1 T, the cathode current density is controlled to be 0.4 A / dm < 2 >-0.6 A / dm < 2 >, the electroplating time is 10-20 min, and a grinding wheel base body B is obtained; removing floating sand from the grinding wheel base body B to obtain a grinding wheel base body C; and the grinding wheel base body C is thickened to obtain a grinding wheel base body D, and the grinding wheel base body D is modified to obtain the grinding wheel. The grinding rate of the manufactured grinding wheel is reduced by 10%-25%, the service life is prolonged by 30%-50%, the machined surface roughness (Ra) can reach 0.3 micrometer or below, and the machined surface precision is reduced by 10%-25%. The grinding wheel is applied to nanoscale grinding of optical glass, sapphire and silicon carbide wafers and forming machining of turbine blade mortises and ceramic matrix composites, and the precision and roughness of the grinding wheel can be effectively guaranteed.

The invention discloses a high-temperature tensile creep testing device for a ceramic matrix composite material, and relates to the technical field of composite material performance tests.The technical scheme includes that the high-temperature tensile creep testing device comprises a testboard, a tensile shell is fixedly connected to the upper portion of the testboard, a servo motor is arranged in the tensile shell, and a worm is arranged at the output end of the servo motor; the worm is rotationally connected with the stretching shell, the worm is in meshed connection with a worm gear, the worm gear is rotationally connected with the stretching shell, the worm gear is fixedly connected with a transmission gear, the transmission gear is in meshed connection with a stretching rack, and the upper portion of the stretching rack is rotationally connected with two clamps. Due to the fact that a wedge-shaped structure is formed between the clamp and the clamping groove, the clamp can clamp inwards while moving downwards, the clamping force borne by the two sides of the ceramic matrix composite sample is increased along with increase of the tensile strength, and the slippage phenomenon caused by the fact that the tensile strength of the two sides of the ceramic matrix composite sample is improved is effectively avoided.

The invention relates to a clamp for a high-temperature vibration test of a ceramic matrix composite turbine guide vane, and aims to solve the problems that the test requirement of the high-temperature vibration test and effective cooling cannot be met in the prior art. The device comprises a high-temperature clamping assembly and a water cooling base. In the aspect of high-temperature testing, the high-temperature clamping assembly is composed of a split-half cover plate, an upper edge plate split-half positioning clamping block and a lower edge plate positioning clamping block, the tightness degree of the clamp is adjusted by adjusting a puller bolt and a threaded piece, stable positioning of the guide vane can be achieved in the axial direction, the radial direction and the circumferential direction, mechanical interference is reduced, and the structure frequency is adjusted. In the aspect of cooling, a multi-channel cooling system is arranged in the water-cooling base, and a nano composite material heat insulation plate is combined, so that high temperature is effectively isolated, and normal operation of the vibration test bed under the high-temperature condition is protected. The device is suitable for testing the vibration performance of the turbine guide vane in an environment of 1100 DEG C, and has the characteristics of high-temperature clamping capability, efficient heat dissipation performance and the like.

The invention relates to the technical field of ceramic material preparation, in particular to core-shell structure ceramic powder and a preparation method and application thereof.The surface of boride ceramic powder is coated with a uniform carbon layer, then the carbon layer is mixed with silicon powder, thermal treatment is conducted through Joule thermal equipment, and the boride ceramic powder coated with a silicon carbide layer is obtained; the prepared composite ceramic powder has good sinterability and oxidation resistance, a composite ceramic block or a ceramic-based composite material is prepared by sintering the composite ceramic powder as a raw material, and the long-acting oxidation / ablation resistance can be effectively improved, so that the composite ceramic powder can be used as a thermal structure component on a remote high-speed aircraft; the preparation process is simple, the reaction condition is mild, the period is short, the cost is low, and the problems that in the prior art, the boride and silicon carbide composite ceramic powder preparation process is complex, and the service requirement in an extreme environment cannot be met are solved.

A combustor for a gas turbine engine includes a ceramic matrix composite (CMC) dome structure, a metallic cowl structure including a single yoke outer cowl connecting flange and a single yoke inner cowl connecting flange, a CMC outer liner, and a CMC inner liner. An outer connection connects the outer cowl connecting flange, the CMC dome structure, and the CMC outer liner in an outer stacked arrangement, and an inner connection connects the inner cowl connecting flange, the CMC dome structure, and the CMC inner liner in an inner stacked arrangement.

The invention relates to a high-performance hafnium-based ultrahigh-temperature ceramic-based composite material and a preparation method thereof. The method comprises the following steps: depositing pyrolytic carbon on the carbon fiber surface of a carbon fiber preform through a CVD (Chemical Vapor Deposition) method; preparing a hafnium oxide interface layer on the surface of the pyrolytic carbon through an atomic layer deposition method, and performing ultra-fast annealing treatment to form a pyrolytic carbon-hafnium oxide composite interface layer; carrying out a reaction with a matrix containing a pyrolytic carbon-hafnium oxide composite interface layer through an impregnation pyrolysis method; a hafnium carbide coating is prepared on the surface of the composite material matrix through a CVD method; and preparing a hafnium oxide coating on the surface of the hafnium carbide coating through an atomic layer deposition method, and carrying out ultra-fast annealing treatment to prepare the high-performance hafnium-based ultra-high-temperature ceramic-based composite material. According to the preparation method, the pyrolytic carbon-hafnium oxide composite interface layer is prepared by adopting an atomic layer deposition process and depending on ultra-fast annealing treatment, and meanwhile, the hafnium carbide-hafnium oxide composite coating is prepared, so that the mechanical property of the composite material in a high-temperature aerobic environment is remarkably improved.

The invention discloses a method for predicting high-temperature and complex stress of a ceramic-based composite material based on strain control damage evolution, and belongs to the technical field of stress prediction of ceramic-based composite materials. The method comprises the following steps: determining material high-temperature performance degradation conditions according to temperature; the total strain (mechanical strain and thermal strain) of the material is calculated, and then based on a three-dimensional failure criterion of strain control, six damage initial criterion equations including stretching and compression in the warp direction, the weft direction and the out-of-plane direction are constructed; establishing an evolution model of damage coefficients by introducing a coupling mechanism of damage factors in different directions; combining a multi-linear constitutive relation of the ceramic matrix composite material to construct a rigidity degradation matrix, and realizing rigidity adjustment of the failure unit; and finally deducing a stress-strain relation equation to complete stress prediction of the material under the conditions of high temperature and complex load. The prediction method provided by the invention can accurately predict the complex stress state of the ceramic matrix composite material under the combined action of the high temperature and the mechanical load.