Additive manufacturing method of continuous fiber reinforced ceramic matrix composite and turbine blade

Abstract

The invention relates to an additive manufacturing method of a continuous fiber reinforced ceramic-based composite material and a turbine blade, belongs to the technical field of additive manufacturing, and solves the problems that in the prior art, 3D printing of the continuous fiber reinforced ceramic-based composite material is difficult to realize, the integrity and consistency of fibers and / or the infiltration of the fibers and a matrix are poor, and the service life of the continuous fiber reinforced ceramic-based composite material is prolonged. And the problem that high-performance turbine blades are difficult to manufacture quickly is solved. An additive manufacturing method of a continuous fiber reinforced ceramic matrix composite comprises the steps that S1, a three-dimensional model of a laminated composite product is established, slicing treatment is conducted, and each layer of two-dimensional fiber fabric is contained in a corresponding slice; s2, prefabricating a two-dimensional fiber fabric in a layered manner; and S3, additive manufacturing of the laminated composite material product is conducted through a selected area photocuring and sinter molding method. According to the method, rapid additive manufacturing of the continuous fiber reinforced ceramic matrix composite material is achieved, fibers in the obtained product have good integrity and consistency, infiltration of the fibers and a matrix is good, and the interface bonding strength is high.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to an additive manufacturing method of a continuous fiber reinforced ceramic matrix composite material and a turbine blade. Background Art

[0002] Continuous fiber reinforced ceramic matrix composites have received extensive attention and rapid development in aerospace, advanced weapons, automobiles and other fields due to their light weight, high temperature resistance, good high temperature strength and good creep resistance.

[0003] At present, the main preparation processes of continuous fiber reinforced ceramic matrix composites include precursor impregnation pyrolysis process (PIP), resin impregnation pyrolysis combined with molten silicon infiltration process (MI) and chemical vapor infiltration process (CVI). However, the above three technical routes are relatively complicated, with long manufacturing cycles and high costs. They require molds, and once the design needs to be changed, complex mold reconstruction is required; and due to repeated heat treatment during the preparation process, fiber stability and consistency have always been the key to its development.

[0004] In recent years, with the continuous development of turbojet engine technology, higher requirements have been put forward for the high temperature performance of turbine blades. Continuous fiber reinforced ceramic matrix composites have become the preferred material for the turbine blades of the new generation of engines, and are also one of the core technologies of future engines. With the rapid development of additive manufacturing technology (i.e. 3D printing technology), the method of preparing continuous fiber reinforced composite materials using additive manufacturing technology has begun to attract attention, but the current additive manufacturing method of continuous fiber reinforced composite materials is mainly "prepreg fiber extrusion + molten deposition molding of thermoplastic resin". This method is only effective for resin-based composite materials. The 3D printing of continuous fiber reinforced ceramic matrix composites is still under exploration, and there is no good mature method. Therefore, finding an additive manufacturing method for continuous fiber reinforced ceramic matrix composites is of great significance for solving the key problems in the molding of continuous fiber reinforced ceramic matrix composites (for example: rapid manufacturing of complex structures, integrity, stability, consistency of continuous fibers, and sufficient infiltration of fibers and matrix). Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide an additive manufacturing method and turbine blade of a continuous fiber reinforced ceramic matrix composite material to solve at least one of the following technical problems: the continuous fiber reinforced ceramic matrix composite material in the prior art is difficult to achieve 3D printing, the fiber integrity, consistency and / or fiber and matrix infiltration are poor, and the rapid manufacturing of high-performance turbine blades is difficult.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides an additive manufacturing method for a continuous fiber reinforced ceramic matrix composite material, wherein the composite material is a laminated composite material, comprising a ceramic matrix and a two-dimensional fiber fabric woven from continuous fibers and distributed in an XY plane;

[0008] The additive manufacturing method comprises the following steps:

[0009] Step S1, establishing a three-dimensional model of a laminated composite material product, and performing slicing processing, wherein each layer of two-dimensional fiber fabric is included in a corresponding slice;

[0010] Step S2, prefabricating two-dimensional fiber fabrics in layers: using a prepreg method to fully infiltrate the two-dimensional fiber fabrics with a thermosetting resin liquid and perform shaping, and preforming into a two-dimensional fiber preform capable of being shaped; processing the two-dimensional fiber preform into a two-dimensional fiber preform of a required shape, and stacking them in the order of slice printing for standby;

[0011] Step S3, additive manufacturing of laminated composite products by selective photocuring + sintering molding method: when printing a certain layer of slices containing two-dimensional fiber fabrics, first accurately lay out the two-dimensional fiber preforms in the corresponding order, position them, and then lay out or spray the ceramic matrix.

[0012] Furthermore, step S2 also includes preparing the two-dimensional fiber fabric by weaving.

[0013] Furthermore, in step S2, the thermosetting resin includes a high temperature curing resin or a photosensitive resin.

[0014] Furthermore, in step S2, the prepreg method includes a spraying and rolling prepreg method and a glue tank rolling prepreg method.

[0015] Furthermore, in step S2, the main steps of the spray-roll prepreg method include: spraying thermosetting resin liquid on the surface of the two-dimensional fiber fabric, fully infiltrating, combining and compacting the two-dimensional fiber fabric and the resin liquid through a rolling method, and shaping through low-temperature precuring or light precuring to obtain a two-dimensional fiber preform.

[0016] Furthermore, in step S2, the main steps of the glue tank rolling prepreg method include: immersing the two-dimensional fiber fabric in a glue tank containing thermosetting resin liquid, fully infiltrating, combining and compacting the two-dimensional fiber fabric and the resin liquid through a rolling method, and shaping through low-temperature precuring or light precuring to obtain a two-dimensional fiber preform.

[0017] Furthermore, the main steps of the rolling method include: squeezing the two-dimensional fiber fabric fully infiltrated with thermosetting resin liquid by a pair of rotating pressure rollers, and at the same time, heating the pressure rollers to achieve low-temperature pre-curing, or irradiating the two-dimensional fiber fabric passing through the pressure rollers with ultraviolet light or laser to achieve light pre-curing.

[0018] Further, step S3 includes the following steps:

[0019] Step S31: preparing ceramic slurry;

[0020] Step S32: Selected area light-curing molding;

[0021] Step S33: degreasing and sintering to obtain a ceramic-based composite material product.

[0022] In a second aspect, the present invention provides a continuous fiber reinforced ceramic matrix composite material and / or product prepared according to the above-mentioned additive manufacturing method of the continuous fiber reinforced ceramic matrix composite material.

[0023] Further, the product is a turbine blade, and the turbine blade includes a blade and a mounting base;

[0024] The blade comprises a blade root, a blade tip, and a blade body extending axially between the blade root and the blade tip, and the blade is a crescent-shaped hollow structure along a section perpendicular to the axial direction;

[0025] The mounting base is a hexahedral hollow structure, and the upper and lower end surfaces include tenon teeth;

[0026] A two-dimensional fiber fabric distributed along the XY plane is distributed inside the turbine blade.

[0027] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0028] 1. The present invention provides an additive manufacturing method for continuous fiber reinforced ceramic matrix composite materials. The method of "layered prefabricated two-dimensional fiber fabric" combined with "ceramic material additive manufacturing process" is adopted to realize the additive manufacturing of continuous fiber reinforced ceramic matrix composite material structures, so that the design freedom of continuous fiber reinforced ceramic matrix composite material structures is well expanded, and the advantages of additive manufacturing can be fully utilized. Highly complex and diversified products can be quickly designed and produced without molds.

[0029] 2. The additive manufacturing method of continuous fiber reinforced ceramic-based composite materials provided by the present invention adopts the method of "layered prefabricated two-dimensional fiber fabric" combined with "ceramic material additive manufacturing process", so that the continuous fiber reinforced ceramic-based composite materials can be rapidly additively manufactured. Compared with the precursor impregnation pyrolysis process (PIP), resin impregnation pyrolysis combined with molten silicon infiltration process (MI) and chemical vapor infiltration process (CVI) in the prior art, the mold processing link can be omitted, the production cycle can be shortened and the cost can be reduced; at the same time, the manufacturing method of the present invention does not require high-temperature pyrolysis, high-temperature vapor phase chemical deposition and other steps, and can adopt simple and efficient process steps to obtain products with very good process quality and performance; among them, since the resin matrix and fibers in the "layered prefabricated two-dimensional fiber fabric" have been fully infiltrated, combined and shaped, and no long-term high-temperature treatment is required during the whole process, the stability, integrity and consistency of the two-dimensional fiber fabric in the final product are better, which can meet the mechanical properties and functional requirements of high-performance ceramic-based composite materials.

[0030] 3. An embodiment of the present invention provides a turbine blade (SiC / SiC composite material) prepared by the additive manufacturing method of the continuous fiber reinforced ceramic matrix composite material. The turbine blade includes a blade and a mounting base. It is integrally formed by combining "layered prefabricated two-dimensional fiber fabric" with "additive manufacturing process (selective photocuring + sintering molding)", which can save the mold processing link in blade manufacturing, maximize the flexibility of structural design, and make the rapid design and additive manufacturing of "hollow structure + continuous fiber reinforcement" turbine blades possible, thereby realizing the optimal design of the structure from a lightweight perspective; the silicon carbide ceramic density of the obtained turbine blade can exceed 95%, the bending strength can reach more than 600Mpa, and it can withstand ambient temperatures above 1700°C, which can fully meet the use requirements of high-performance engines.

[0031] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0033] Figure 1 A schematic diagram of a laminated composite material provided by an embodiment of the present invention;

[0034] Figure 2An axonometric schematic diagram of a turbine blade provided by an embodiment of the present invention;

[0035] Figure 3 A Y-direction schematic diagram of a turbine blade provided in an embodiment of the present invention;

[0036] Figure 4 A schematic diagram of a turbine blade in the Z direction provided by an embodiment of the present invention;

[0037] Figure 5 A cross-sectional view of a slice of a layer of a two-dimensional fiber fabric included in a turbine blade provided by an embodiment of the present invention;

[0038] Figure 6 A schematic diagram of a two-dimensional fiber fabric sliced ​​from a certain layer of a turbine blade provided by an embodiment of the present invention;

[0039] Reference numerals:

[0040] 101-Z-direction section including fiber and matrix; 102-XY plane section, i.e., the plane where the two-dimensional fiber fabric is located; 2-blade; 21-blade root; 22-blade body; 23-blade tip; 24-groove; 3-mounting base; 31-tenon. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0042] The present invention provides an additive manufacturing method for a continuous fiber reinforced ceramic matrix composite material, wherein the composite material is a laminated composite material, comprising a ceramic matrix and a two-dimensional fiber fabric woven from continuous fibers and distributed in an XY plane;

[0043] The additive manufacturing method comprises the following steps:

[0044] Step S1: Establish a three-dimensional model of a laminated composite material product and perform slicing processing, wherein each layer of two-dimensional fiber fabric is included in a corresponding slice.

[0045] Step S1 specifically includes the following steps:

[0046] Step S11: using computer-aided design software to establish a three-dimensional model of the laminated composite material product;

[0047] Specifically, in the established three-dimensional model, the two-dimensional fiber fabric in the laminated composite product is distributed in the XY plane and accumulated in multiple layers. There is no fiber in the product along the Z direction perpendicular to the XY plane. The XY plane is also the base plane for future additive manufacturing. For example, refer to Figure 1, 101 is the Z-direction section including the fiber and the matrix. Because there is no Z-direction fiber, what can be seen in the Z-direction section is the fiber cross section and the matrix cross section. 102 is the section of the XY plane. Since the fibers are distributed in the XY plane, the fiber distribution of the two-dimensional fabric can be seen.

[0048] Optionally, the thickness of each layer of two-dimensional fiber fabric in the laminated composite material product is less than 0.5 mm. Preferably, the thickness of each layer of two-dimensional fiber fabric is less than 0.1 mm.

[0049] It should be noted that the surface of the laminated composite material product is a matrix material that does not contain fibers; such a setting can ensure that the surface of the laminated composite material product is completely flat, and the fiber fabric can be fully covered in the product shape to ensure that no fibers are exposed on the product surface after molding.

[0050] Preferably, the thickness of the matrix material (excluding fibers) of the laminated composite product along the Z-upward and lower surfaces is not less than 0.1 mm; more preferably, the thickness of the matrix material (excluding fibers) of the laminated composite product along the Z-upward and lower surfaces is not less than 0.5 mm.

[0051] Preferably, the outer contour of the two-dimensional fiber fabric distributed in the XY plane of the laminated composite material product is 0.1 mm to 0.3 mm smaller than the outer contour of the product.

[0052] It should be noted that the number of layers of the two-dimensional fiber fabric can be selected as needed, and the number of layers is a natural number greater than or equal to 2; further, the material, thickness and fiber arrangement of each layer of the two-dimensional fiber fabric can be the same or different;

[0053] In a possible design, each layer of the two-dimensional fiber fabric has the same material, thickness, and fiber arrangement.

[0054] In one possible design, each layer of the two-dimensional fiber fabric has the same material and thickness, but the fiber arrangement is different.

[0055] It should be noted that the distribution of the two-dimensional fiber fabric in the matrix can be selected as needed. For example, two or more layers of two-dimensional fiber fabric are evenly or non-evenly stacked layer by layer in the matrix along a plane perpendicular to the Z direction.

[0056] Optionally, computer-aided design (CAD) software can be selected as needed, including but not limited to AutoCAD, Autodesk Inventor, SolidWorks, CATIA, Pro / E, UG NX, SolidEdge, Onespace, etc.

[0057] Step S12: convert the three-dimensional model of the laminated composite product into an STL triangulated file, set the XY plane where the two-dimensional fiber fabric is located as the base plane of 3D printing, set the Z direction perpendicular to the XY plane as the layer-by-layer stacking direction, and slice the STL triangulated file.

[0058] Specifically, the three-dimensional model of the laminated composite product established in step S11 is converted into the STL triangulated file required by the additive manufacturing system, the XY plane of the laminated composite product (that is, the plane where each layer of two-dimensional fiber fabric is located) is determined as the base plane of 3D printing, and the Z direction perpendicular to the XY plane is set as the layer-by-layer stacking direction. The STL triangulated file is sliced ​​to realize the conversion of the three-dimensional model into a two-dimensional thin film model.

[0059] It should be noted that when slicing, it is necessary to ensure that each layer of the two-dimensional fiber fabric is contained in the corresponding slice, that is, the substrate of each slice thickness completely wraps the two-dimensional fiber fabric of this layer, so that the surface is flat after laying each layer of substrate material to ensure smooth subsequent printing operations, for example, the scraper motion system can move smoothly to lay each layer of printing material;

[0060] In order to meet the above requirements, the slice thickness is greater than the thickness of the two-dimensional fiber fabric; optionally, the thickness of each layer of the two-dimensional fiber fabric can be the same or different, and the maximum thickness of the two-dimensional fiber fabric is set as M 1 , satisfying, N>M 1 , N is the slice thickness, M 1 is the maximum thickness in the two-dimensional fiber fabric. Optionally, N is 0.025 mm to 0.5 mm; preferably, N is 0.05 mm to 0.1 mm; illustratively, M 1 =0.08mm, N=0.1mm.

[0061] It should be noted that the first and last layers of the slice are matrix materials that do not contain fibers, satisfying N<S, where N is the slice thickness, and S is the thickness of the matrix material (i.e., does not contain fibers) on the upper and lower surfaces of the laminated composite product along the Z direction; optionally, N is 0.025mm~0.5mm; preferably, N is 0.05mm~0.1mm; exemplarily, S=0.6mm, N=0.1mm.

[0062] It can be seen that the slice thickness N is selected according to the thickness of the two-dimensional fiber fabric and the thickness of the matrix material on the upper and lower surfaces of the product along the Z direction, ensuring that each layer of the two-dimensional fiber fabric is contained in the corresponding slice, and the first and last layers of the slice are matrix materials that do not contain fibers, so as to ensure the smooth progress of subsequent printing operations, and that the fiber fabric can be fully covered in the shape of the product after molding, ensuring that the surface of the laminated composite product is completely flat.

[0063] In one possible design, after converting the 3D model into an STL file, support can be generated by software at the bottom of the 3D model or at a location with a large slope, and the 3D model and support can be sliced ​​and imported into the 3D printing system control host together. The support here is mainly a temporary structure added to maintain the shape and stability of the printed object, which can be easily removed after printing.

[0064] Step S2, prefabricating two-dimensional fiber fabrics in layers: using a prepreg method to fully infiltrate the two-dimensional fiber fabrics with a thermosetting resin liquid and perform shaping, and preforming into a two-dimensional fiber preform capable of being shaped; processing the two-dimensional fiber preform into a two-dimensional fiber preform of a required shape, and stacking them in the order of slice printing for standby;

[0065] The specific steps include:

[0066] Step S21: preparing a two-dimensional fiber fabric by weaving;

[0067] Specifically, a plurality of fiber bundles are regularly interlocked alternately by weaving to form a two-dimensional fiber fabric. The weaving method of the two-dimensional fiber fabric can be selected according to needs, including but not limited to weaving, braiding, knitting, etc.

[0068] It should be noted that the diameter of the fiber bundle used to prepare the two-dimensional fiber fabric is determined according to the thickness of the slice in step S1 to satisfy N>M 1 , N is the slice thickness, M 1 is the maximum thickness of a two-dimensional fiber fabric.

[0069] In a possible design, the slice thickness N is 0.05 mm to 0.1 mm. To satisfy N>M 1 Preferably, the fibers used to prepare the two-dimensional fiber fabric are ultra-small tow fibers, and the ultra-small tow fibers are fibers not larger than 1K, where 1K means that a bundle of fiber filaments contains 1000 single filaments; more preferably, the fibers used to prepare the two-dimensional fiber fabric are ultra-small tow fibers of 0.1K to 0.8K;

[0070] For example, the slice thickness N=0.1 mm, the fiber bundle is 0.12K (each bundle has 120 fiber filaments), and the diameter of the filament is 8 μm, which can ensure that the thickness of the prepared two-dimensional fiber fabric is less than 0.1 mm.

[0071] Optionally, the fiber type for preparing the two-dimensional fiber fabric can be selected as needed, including but not limited to one or a combination of silicon carbide fiber, carbon fiber, silicon nitride fiber, boron fiber, basalt fiber, glass fiber, aramid fiber, and alumina (including mullite) fiber.

[0072] Optionally, the fiber arrangement of the two-dimensional fiber fabric can be selected according to needs (for example, the direction of force on the product, etc.), including but not limited to unidirectional fabric, plain fabric, twill fabric, etc. For example, the unidirectional fabric is a thinner two-dimensional fiber fabric in which the fibers are subjected to force in the main direction by evenly laying a large number of fiber filaments along a main direction and weaving the fiber filaments in the main direction together with fewer fiber filaments; see Figure 6 The two-dimensional fiber fabric corresponding to the slice adopts the shape of a unidirectional cloth. The fibers in the two-dimensional fiber fabric are mainly distributed along the Y direction, and a smaller amount of fibers are distributed along the X direction, which plays a role in linking and fixing the Y-direction fibers.

[0073] Step S22: The two-dimensional fiber fabric is fully impregnated with the liquid of the thermosetting resin by the pre-impregnation method and then shaped to be preformed into a two-dimensional fiber preform that can be shaped so as to maintain the existing shape when being picked up and placed.

[0074] It should be noted that thermosetting resins are resins that are liquid at room temperature but can be cross-linked and cured under heating or light, including high-temperature curing resins or photosensitive resins.

[0075] Optionally, the type of thermosetting resin can be selected as needed, including but not limited to epoxy resin, epoxy acrylate, polyurethane acrylic resin, polyester acrylic resin, amino acrylic resin, phenolic resin, urea-formaldehyde resin, melamine-formaldehyde resin, unsaturated resin, polyurethane, and polyimide.

[0076] It should be noted that the prepreg method includes the spray rolling prepreg method and the glue tank rolling prepreg method.

[0077] The main steps of the spray-roll prepreg method include: spraying thermosetting resin liquid on the surface of the two-dimensional fiber fabric, fully infiltrating and compacting the two-dimensional fiber fabric with the resin liquid through rolling, and shaping it through low-temperature precuring or light precuring to obtain a two-dimensional fiber preform.

[0078] The main steps of the glue tank rolling prepreg method include: immersing the two-dimensional fiber fabric in a glue tank containing thermosetting resin liquid, fully impregnating and compacting the two-dimensional fiber fabric with the resin liquid through rolling, and shaping it through low-temperature precuring or light precuring to obtain a two-dimensional fiber preform.

[0079] Furthermore, the main steps of the rolling method in the spray rolling prepreg method or the glue tank rolling prepreg method include: squeezing the two-dimensional fiber fabric fully infiltrated with thermosetting resin liquid by a pair of rotating pressure rollers, and at the same time, heating the pressure rollers to achieve low-temperature precuring, or irradiating the two-dimensional fiber fabric passing through the pressure rollers with ultraviolet light or laser to achieve light precuring.

[0080] In a possible design, a high-temperature curing resin is sprayed on the surface of the two-dimensional fiber fabric, and the pressure roller can be heated in the rolling method to pre-cure the resin on the surface of the two-dimensional fiber fabric passing through the pressure roller at a low temperature, thereby achieving the shaping of the two-dimensional fiber fabric. Exemplarily, the high-temperature curing resin is selected from epoxy resin, and the curing temperature of the epoxy resin is 120°C. The pre-impregnated two-dimensional fiber fabric is pre-cured at a low temperature by a pressure roller preheated to 60°C to become a two-dimensional fiber preform with a certain shape and stiffness.

[0081] In a possible design, the two-dimensional fiber fabric is immersed in a glue tank containing a photosensitive resin liquid, and a certain amount of ultraviolet light or laser can be irradiated to the material passing through the pressure roller in the rolling method, and the photosensitive resin on the surface of the two-dimensional fiber fabric is photo-precured under the action of the laser or ultraviolet light, thereby achieving the shaping of the two-dimensional fiber fabric. Exemplarily, the photosensitive resin is selected as epoxy acrylate, and the two-dimensional fiber fabric pre-impregnated with epoxy acrylate passes through a pair of rotating pressure rollers, and an ultraviolet solid laser is used to irradiate the material passing between the pressure rollers, so that the epoxy acrylate sprayed on the surface of the two-dimensional fiber fabric is photo-precured to become a two-dimensional fiber preform with a certain shape and rigidity.

[0082] It should be noted that in order to ensure the smooth progress of 3D printing, the thickness of the 2D fiber preform is less than the slice thickness, satisfying M 1 ≤M 2 <N,M 1 is the maximum thickness of the two-dimensional fiber fabric, M 2 is the maximum thickness of the two-dimensional fiber preform, and N is the slice thickness; optionally, N is 0.025 mm to 0.5 mm; preferably, N is 0.05 mm to 0.1 mm.

[0083] It is worth noting that the two-dimensional fiber fabric preform obtained by pre-preg method has good rigidity and can maintain the existing shape of the two-dimensional fiber fabric during the pick-up and placement operations. At the same time, the pre-preg method makes the two-dimensional fiber fabric and the thermosetting resin fully infiltrated and shaped, which can well maintain the uniformity, stability, integrity and consistency of the two-dimensional fiber fabric in the subsequent 3D printing process and the final product.

[0084] Step S23: Processing the two-dimensional fiber preform into a two-dimensional fiber preform of a required shape, and stacking them in the order of slice printing for standby use.

[0085] Specifically, the two-dimensional fiber preform is processed into a two-dimensional fiber preform of a desired shape by a cutting process, and the number of layers and the outer contour of the two-dimensional fiber preform are determined according to the two-dimensional fiber fabric in the three-dimensional model of the laminated composite product established in step S1. For example, if four layers of two-dimensional fiber fabric are set at the 200th, 300th, 400th and 500th layers in the three-dimensional model, then four two-dimensional fiber preforms are cut out according to the outer contour of the corresponding slice layer, and the outer contour of each two-dimensional fiber preform is slightly smaller than the outer contour of the corresponding slice layer to ensure that no fiber is exposed on the surface of the product after molding.

[0086] Optionally, the cutting process can be selected as needed, including but not limited to automatic cutting, laser cutting, etc. Exemplarily, the automatic cutting method can use a CNC cutting machine to cut the two-dimensional fiber preform to obtain a two-dimensional fiber preform of a desired shape.

[0087] Step S3: Additive manufacturing of laminated composite products by selective photocuring + sintering molding method: When printing a layer of slices containing two-dimensional fiber fabrics, first accurately lay out the two-dimensional fiber preforms in the corresponding order, position them, and then lay or spray the ceramic matrix.

[0088] It should be noted that the main steps of accurately laying out the two-dimensional fiber preforms in the corresponding order include: before laying out or spraying a certain layer of the matrix, accurately locating the placement position of the two-dimensional fiber preforms of the corresponding layer of the matrix to be sprayed by infrared scanning, and laying them on the printed previous layer. Exemplarily, before laying out or spraying a certain layer of the matrix, the two-dimensional fiber preforms of the corresponding layer are automatically picked up by a robot, and the placement position of the two-dimensional fiber preforms of the corresponding layer of the matrix to be sprayed is accurately located by infrared scanning, and laid on the printed previous layer.

[0089] It should be noted that the main steps of the positioning include: after accurately placing the two-dimensional fiber preform of the corresponding layer, selecting W positioning points on the two-dimensional fiber preform, scanning the positioning points with laser or ultraviolet light for thermal curing or photocuring positioning (the resin at the positioning points is heated or irradiated with light to undergo thermal curing or photocuring), similar to the mechanism of metal spot welding, so that the two-dimensional fiber preform is fixed on the printed previous layer to ensure that the two-dimensional fiber preform will not move when the corresponding layer of matrix material is placed later.

[0090] Preferably, the number of positioning points W is ≥ 3, and they are not on a straight line to better ensure effective positioning.

[0091] Specifically, step S3 includes the following steps:

[0092] Step S31: preparing ceramic slurry;

[0093] Purchase commercially available ceramic slurries that can be used for 3D printing (including ceramic powders and photosensitive resins, etc.);

[0094] Step S32: Selected area light-curing molding;

[0095] The STL data file generated in step S1 is imported into the 3D printer system, and the ceramic slurry prepared in step S31 is placed in the material tank of the 3D printer to perform selective photocuring printing to obtain a precursor of a ceramic-based composite material product.

[0096] The printing equipment and specific process parameters of the selective photocuring molding can be selected and set from the parameters of the 3D printer and 3D printing molding technology in the prior art.

[0097] In one possible design, the 3D printer is equipped with a peristaltic feeding system and a precision scraper paving system. The peristaltic feeding system ensures the precise supply of ceramic materials, and the precision scraper paving system ensures that each layer of slurry is evenly spread, thereby ensuring that the thickness of each printed layer is uniform and controllable.

[0098] In one possible design, step S32 includes the following steps:

[0099] Step S321: When printing a certain layer of slices containing fibers, the robot automatically picks up the two-dimensional fiber preform of the current layer, and accurately positions and places it by infrared scanning. After placing the two-dimensional fiber preform of the current layer, ultraviolet light is used to scan W points on the two-dimensional fiber preform for light curing positioning; W ≥ 3, and not on a straight line;

[0100] Step S322: the peristaltic feeding system controls the quantitative supply of the ceramic slurry;

[0101] Step S323: The precision scraper motion system flattens the ceramic slurry in step S322;

[0102] Step S324: Scan the slice of the current layer with ultraviolet light to solidify it sequentially from point to line and from line to surface, thus completing the light curing of the current layer;

[0103] Step S325: the molding printing platform descends one layer, and the precision scraper motion system returns to continue printing the next layer;

[0104] It can be understood that when printing a slice layer containing fibers, the printing is performed according to the above steps S321 to S325; when printing a slice layer not containing fibers, the printing is performed according to steps S322 to S325;

[0105] Repeat steps S321 to S325, or steps S322 to S325, until the last slice layer is printed, to obtain a precursor of a ceramic-based composite material product.

[0106] Step S33: degreasing and sintering;

[0107] The precursor of the ceramic-based composite material product printed in step S32 is placed in a degreasing furnace, where the photosensitive resin, various additives, and the resin used for pre-impregnating the two-dimensional fiber fabric in step S2 in the precursor of the ceramic-based composite material product are volatilized and completely discharged;

[0108] Furthermore, the degreased precursor of the ceramic-based composite material product is placed in a high-temperature sintering furnace and sintered according to a certain sintering process to obtain the final ceramic-based composite material product.

[0109] The specific process parameters of debinding and sintering molding can be selected and set from the process parameters of debinding and sintering of ceramic materials in the prior art.

[0110] The present invention also provides a continuous fiber reinforced ceramic matrix composite material and / or product prepared according to the additive manufacturing method of the continuous fiber reinforced ceramic matrix composite material.

[0111] The product is a turbine blade, such as Figure 2 , Figure 3 and Figure 4 , the turbine blade 200 comprises a blade 2 and a mounting base 3;

[0112] The blade 2 includes a blade root 21, a blade tip 23, and a blade body 22 extending axially between the blade root 21 and the blade tip 23. The blade 2 is a crescent-shaped hollow structure along a cross section perpendicular to the axial direction.

[0113] The mounting base 3 is a hexahedral hollow structure, and the upper and lower end surfaces include tenon teeth 31;

[0114] A two-dimensional fiber fabric distributed along the XY plane is distributed inside the turbine blade 200 .

[0115] Preferably, the blade tip 23 of the blade 2 comprises a groove 24 .

[0116] Furthermore, the wall thickness of the blade 2 can be selected as needed. Preferably, the wall thickness of the groove 24 is the same, and the wall thickness of the blade body 22 is the same as the wall thickness of the groove 24 .

[0117] Preferably, a plurality of air holes are provided on the blade body 22 and / or the groove 24 of the blade 2. The air holes are used to allow gas to flow into the hollow structure of the turbine blade, thereby cooling the turbine blade.

[0118] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments.

[0119] Embodiment 1:

[0120] This embodiment provides an additive manufacturing method for continuous silicon carbide fiber reinforced silicon carbide (SiC / SiC composite material) turbine blades.

[0121] like Figure 2 , Figure 3 and Figure 4 The turbine blade 200 includes a blade 2 and a mounting base 3; the blade 2 includes a blade root 21, a blade tip 23, and a blade body 22 extending axially (i.e., in the Y direction) between the blade root 21 and the blade tip 23; the blade 2 is a crescent-shaped hollow structure along a section (i.e., an XZ plane) perpendicular to the axial direction (i.e., in the Y direction), and the bending direction of the crescent is the X direction; the mounting base 3 is a trapezoidal hollow structure, and the upper end face and the lower end face along the XY plane respectively include three tenons, and the surface with the largest area in the mounting base 3 is connected to the blade 2; a two-dimensional fiber fabric distributed along the XY plane is distributed in the turbine blade 200; the blade tip 23 of the blade 2 includes a groove 24, the wall thickness of the groove 24 is the same, and the wall thickness of the blade body 22 is the same as the wall thickness of the groove 24; four circular air holes are opened on the groove 24 of the blade 2.

[0122] The material of the turbine blade 200 is silicon carbide reinforced with continuous silicon carbide fibers, that is, SiC / SiC composite material.

[0123] The additive manufacturing method of the turbine blade 200 comprises the following steps:

[0124] Step S1: Use UG (Unigraphics NX) software to design and model to form a three-dimensional model of the turbine blade, such as Figure 2 , Figure 3 , Figure 4 ; Convert the 3D model into the STL triangulated file required by the additive manufacturing system, set the slice thickness to 0.1 mm, determine the XY plane of the turbine blade (that is, the plane where each layer of the 2D fiber fabric is located) as the base plane of 3D printing, set the Z direction perpendicular to the XY plane as the layer-by-layer stacking direction, and perform the slicing operation on the 3D model; Figure 5 A schematic cross-sectional diagram showing a slice of a turbine blade, with red representing the cut surface and the remaining grey representing the non-cut surface (i.e., the surface).

[0125] The total length of the turbine blade 200 in the Y direction (i.e., the axial direction) is 120 mm, the total length in the Z direction is 73 mm, and the total length in the X direction is 50 mm. According to the length of 73 mm in the Z direction, the slice thickness is 0.1 mm, and the total number of slices is 730 layers. In this embodiment, a total of 4 layers of two-dimensional fiber fabrics are provided, and the positions of these 4 layers of fabrics in the Z direction are respectively at the 200th, 300th, 400th, and 500th layers of the printed slices, ensuring that the outer contour of each layer of two-dimensional fiber fabric is 0.2 mm smaller than the outer edge of the slice where the corresponding layer of two-dimensional fiber fabric is located, so that the 4 layers of two-dimensional fiber fabrics can be fully covered in the corresponding slice shape.

[0126] Step S2, prefabricating two-dimensional fiber fabrics in layers;

[0127] Step S21: Select fiber bundles 0.12K (each bundle has 120 silicon carbide filaments) and silicon carbide fibers with a single filament diameter of 8 μm, and prepare silicon carbide two-dimensional fiber fabrics by weaving, such as Figure 6 As shown, the fibers in the two-dimensional fiber fabric are mainly distributed along the Y direction, and a smaller amount of fibers are distributed along the X direction, which plays a role in linking and fixing the Y-direction fibers; such a setting is mainly considered that the main force direction of the turbine blade is the Y direction;

[0128] Step S22: Before 3D printing, the silicon carbide two-dimensional fiber fabric is pretreated by spraying and rolling prepreg method. Specifically, a layer of epoxy resin liquid (curing temperature is 120°C) is sprayed on the surface of the silicon carbide two-dimensional fiber fabric, and then the silicon carbide two-dimensional fiber fabric fully soaked in the epoxy resin liquid is squeezed by a rotating pair of rollers through a rolling method, and the rollers are heated to 60°C at the same time to achieve low-temperature precuring to obtain a two-dimensional fiber preform with a certain shape and rigidity. By controlling the spraying amount and / or rolling parameters, it is ensured that the two-dimensional fiber fabric is fully soaked, combined and compacted with the epoxy resin liquid, and the thickness of the two-dimensional fiber preform is ensured to be less than 0.1mm;

[0129] Step S23: according to the outer contours of the 200th, 300th, 400th and 500th layers of slices, the two-dimensional fiber preform is cut by a CNC cutting machine, and each layer of the two-dimensional fiber fabric is ensured to be 0.2 mm smaller than the outer contour of the corresponding layer of slices during cutting, so as to obtain a four-layer two-dimensional fiber preform of the desired shape.

[0130] Step S31: preparing ceramic slurry;

[0131] Commercially available silicon carbide ceramic slurry that can be used for 3D printing is purchased, the ceramic powder is SiC ceramic, and the photosensitive resin is epoxy resin.

[0132] Step S32: Selected area light-curing molding;

[0133] Step S321: when printing a certain layer of slices containing fibers, the robot automatically picks up the two-dimensional fiber preform of the current layer, and accurately positions and places it by infrared scanning. After placing the two-dimensional fiber preform of the current layer, ultraviolet light is used to scan four points on the two-dimensional fiber preform (not on a straight line) for light curing positioning, so that the two-dimensional fiber preform is fixed on the printed previous layer;

[0134] Step S322: the peristaltic feeding system controls the quantitative supply of silicon carbide ceramic slurry;

[0135] Step S323: The precision scraper motion system flattens the silicon carbide ceramic slurry in step S322;

[0136] Step S324: Scan the slice of the current layer with ultraviolet light to solidify it sequentially from point to line and from line to surface, thus completing the light curing of the current layer;

[0137] Step S325: The molding printing platform descends one layer, and the precision scraper motion system returns to continue printing the next layer.

[0138] Among them, the 200th, 300th, 400th and 500th layers are slice layers containing two-dimensional fiber fabrics, and 3D printing is performed according to the above steps S321 to S325. The remaining layers repeat steps S322 to S325 for 3D printing until the last layer of slices is printed to obtain the precursor of the turbine blade.

[0139] Step S33: Place the turbine blade precursor into a degreasing furnace with a degreasing temperature of about 500°C and a degreasing time of 120 minutes, so that the epoxy resin and the like in the turbine blade precursor can be volatilized and completely discharged; perform hot isostatic pressing on the degreased turbine blade precursor with a sintering temperature of 1600°C to 2000°C and a nitrogen filling pressure of 100MPa, and keep the temperature and pressure for 24 hours to obtain the final SiC / SiC composite turbine blade.

[0140] The silicon carbide ceramic density of the turbine blade obtained in this embodiment can exceed 95%, the bending strength can reach more than 600 MPa, and it can withstand an ambient temperature of more than 1700°C, which can fully meet the use requirements of high-performance engines.

[0141] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for additive manufacturing of continuous fiber reinforced ceramic matrix composite materials, characterized in that: The composite material is a laminated composite material, comprising a ceramic matrix and a two-dimensional fiber fabric woven from continuous fibers and distributed in an XY plane; The additive manufacturing method comprises the following steps: Step S1, establishing a three-dimensional model of a laminated composite material product, and performing slicing processing, wherein each layer of two-dimensional fiber fabric is included in a corresponding slice; Step S2, prefabricating two-dimensional fiber fabrics in layers: using a prepreg method to fully infiltrate the two-dimensional fiber fabrics with a thermosetting resin liquid and perform shaping, and preforming into a two-dimensional fiber preform capable of being shaped; processing the two-dimensional fiber preform into a two-dimensional fiber preform of a required shape, and stacking them in the order of slice printing for standby; Step S3, additive manufacturing of laminated composite products by selective photocuring + sintering molding method: when printing a certain layer of slices containing two-dimensional fiber fabrics, first accurately lay out the two-dimensional fiber preforms in the corresponding order, position them, and then lay out or spray the ceramic matrix.

2. The additive manufacturing method of continuous fiber reinforced ceramic matrix composite material according to claim 1, characterized in that: Step S2 also includes preparing a two-dimensional fiber fabric by weaving.

3. The additive manufacturing method of continuous fiber reinforced ceramic matrix composite material according to claim 1, characterized in that: In step S2, the thermosetting resin includes a high temperature curing resin or a photosensitive resin.

4. The additive manufacturing method of continuous fiber reinforced ceramic matrix composite material according to claim 1, characterized in that: In step S2, the prepreg method includes a spray rolling prepreg method and a glue tank rolling prepreg method.

5. The additive manufacturing method of continuous fiber reinforced ceramic matrix composite material according to claim 4, characterized in that: In step S2, the main steps of the spray-roll prepreg method include: spraying thermosetting resin liquid on the surface of the two-dimensional fiber fabric, fully infiltrating, combining and compacting the two-dimensional fiber fabric and the resin liquid through a rolling method, and shaping through low-temperature precuring or light precuring to obtain a two-dimensional fiber preform.

6. The additive manufacturing method of continuous fiber reinforced ceramic matrix composite material according to claim 4, characterized in that: In step S2, the main steps of the glue tank rolling prepreg method include: immersing the two-dimensional fiber fabric in a glue tank containing thermosetting resin liquid, fully infiltrating, combining and compacting the two-dimensional fiber fabric and the resin liquid by rolling, and shaping by low-temperature precuring or light precuring to obtain a two-dimensional fiber preform.

7. The additive manufacturing method of continuous fiber reinforced ceramic matrix composite material according to claim 5 or 6, characterized in that: The main steps of the rolling method include: squeezing the two-dimensional fiber fabric fully soaked in thermosetting resin liquid by a pair of rotating pressure rollers, and at the same time, heating the pressure rollers to achieve low-temperature pre-curing, or irradiating the two-dimensional fiber fabric passing through the pressure rollers with ultraviolet light or laser to achieve light pre-curing.

8. The additive manufacturing method of continuous fiber reinforced ceramic matrix composite material according to claim 1, characterized in that: Step S3 includes the following steps: Step S31: preparing ceramic slurry; Step S32: Photocuring of selected areas; Step S33: degreasing and sintering to obtain a ceramic-based composite material product.

9. A continuous fiber reinforced ceramic matrix composite material and / or product prepared by the additive manufacturing method of a continuous fiber reinforced ceramic matrix composite material according to any one of claims 1 to 8.

10. The product according to claim 9, characterized in that The product is a turbine blade, and the turbine blade (200) comprises a blade (2) and a mounting base (3); The blade (2) comprises a blade root (21), a blade tip (23), and a blade body (22) extending axially between the blade root (21) and the blade tip (23); the blade (2) is a crescent-shaped hollow structure along a cross section perpendicular to the axial direction; The mounting base (3) is a hexahedral hollow structure, and the upper end surface and the lower end surface include tenon teeth (31); A two-dimensional fiber fabric distributed along the XY plane is distributed inside the turbine blade (200).

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