Multipurpose tool for large-size curved-surface ceramic matrix composite component and RMI process method

Abstract

The invention provides a multipurpose tool for a large-size curved surface ceramic matrix composite component and an RMI process method, and aims to solve the problems that an existing RMI box type tool is only suitable for integral RMI of flat plate type parts and cannot realize directional permeation of local areas, and for curved surface parts, the flow of silicon or silicon-based alloy in a molten state cannot be limited, so that the service life of the curved surface parts is prolonged. And non-uniform permeation of the component is easily caused, and the quality of the component is influenced. According to the multipurpose tool for the large-size curved-surface ceramic-based composite material component, a plurality of powder filling areas are formed in the box-shaped tool through the grating structure which follows the shape of the component, on one hand, the flowing path of silicon or silicon-based alloy in a molten state can be well optimized through all the powder filling areas, the infiltration uniformity during RMI is effectively guaranteed, and on the other hand, the stability of the component is improved; and on the other hand, the filling area can be filled with different powder materials, so that targeted infiltration of local parts of the components is achieved, the powder materials can be separated, material clearing after RMI is facilitated, and the quality of finished products is improved.

Description

Technical Field

[0001] The invention relates to a reactive melt infiltration process, in particular to a multi-purpose tooling and RMI process method for large-size curved surface ceramic matrix composite material components. Background Art

[0002] Reactive melt infiltration (RMI) is usually carried out at a high temperature of about 1600℃. For flat components, a simple box-type structural tooling can ensure that the overall density and uniformity of the component meet the requirements. However, when using the RMI method to prepare components with special curved surface structures, the existing box-type structural tooling will face the following problems: (1) The box-type structural tooling cannot fit the component surface and cannot provide stable support for it, which is easy to cause structural deformation and affect product quality; (2) Silicon or silicon-based alloys will melt at high temperatures and flow slowly along the tooling or part surface, affecting the infiltration uniformity; (3) For components with special density requirements in local areas, it is impossible to achieve directional infiltration in local areas.

[0003] A profiling device and method for preparing ceramic-based composite material workpieces based on the RMI method is disclosed in a Chinese invention patent with publication number CN 15284412A. The profiling device in the method is composed of a plurality of parallel card plate groups with overflow grooves and a support seat, and the support seat is provided with card grooves corresponding to the card plate groups one by one, which are used to insert and fix the card plate groups. The profiling of the flat plate components during the RMI process is completed by placing the flat plate components between the gaps reserved by the upper and lower card plates. However, the profiling device is only applicable to the overall RMI of flat plate parts, and cannot achieve directional penetration in local areas; for curved parts, the overflow grooves provided on the profiling device cannot limit the flow of molten silicon or silicon-based alloys, which can easily cause uneven penetration of the components and affect the quality of the components. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems that the existing RMI box-type tooling is only suitable for the overall RMI of flat parts, cannot achieve directional penetration in local areas, and cannot limit the flow of molten silicon or silicon-based alloys for curved parts, which easily leads to uneven penetration of components and affects the quality of components, and to provide a multi-purpose tooling and RMI process method for large-sized curved ceramic-based composite components.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A multi-purpose tooling for a large-sized curved surface ceramic matrix composite component, which is special in that it includes a box-type tooling, a grid frame and a shape adjustment component;

[0007] The box-type tooling is a box-shaped structure with an open top surface;

[0008] The grid frame includes an external frame, a plurality of transverse grids and a plurality of longitudinal grids;

[0009] The shape of the external frame is compatible with the shape of the large-sized curved surface ceramic-based composite material component, and the size of the external frame in each direction is 20 to 50 mm larger than the size of the large-sized curved surface ceramic-based composite material component in the corresponding direction;

[0010] A plurality of equally spaced transverse grids and a plurality of equally spaced longitudinal grids are intersected and located in the external frame, and the bottoms are flush, so that a plurality of grid structures are formed in the external frame; the upper surface shape of the grid structure is adapted to the surface shape of the large-sized curved surface ceramic matrix composite material component;

[0011] The top of the external frame is higher than the top of the transverse grid and the longitudinal grid, and both ends of the transverse grid and the longitudinal grid connected to the external frame are respectively provided with upward flanges; a slot is radially provided at the inner side of the flange near the upper surface of the grid structure, and the distance between the bottom surface of each slot and the upper surface of the corresponding grid structure is equal to the thickness of the corresponding part of the large-size curved surface ceramic-based composite material component;

[0012] The shaping assembly includes a plurality of shaping baffles that follow the boundary portion of the large-sized curved surface ceramic-based composite material component; the plurality of shaping baffles are horizontally installed in corresponding slots, respectively, to clamp the large-sized curved surface ceramic-based composite material component on the upper surface of the grid structure;

[0013] The grid frame is arranged in the box-type tooling along the horizontal direction, and the grid structure cooperates with the bottom of the box-type tooling to form a powder filling area.

[0014] Further, the box-shaped tooling is made of graphite;

[0015] The outer frame, transverse grid and longitudinal grid of the grid frame are all made of graphite, or carbon material, or carbon / silicon carbide composite material;

[0016] The shape correction piece is made of graphite, or carbon material, or carbon / silicon carbide composite material.

[0017] Furthermore, the area of ​​each grid structure is 3% to 8% of the area of ​​the large-sized curved surface ceramic-based composite material component, and the width of the grid structure is 1% to 3% of its circumference.

[0018] Furthermore, the height of the card slot is 2 to 5 mm;

[0019] The distance between two adjacent shaping baffles is 100 to 250 mm;

[0020] The length L1 and width W1 of the shaping piece are respectively:

[0021] L1=W2+10~20mm

[0022] W1=D+10~20mm

[0023] Wherein, W2 is the width of the transverse grille or the longitudinal grille, and D is the depth of the slot.

[0024] Furthermore, the minimum height of the transverse grid is 15 to 40 mm;

[0025] The minimum height of the longitudinal grid is 15-40 mm.

[0026] Furthermore, the distance between the plurality of flanges and corresponding boundary portions of the large-sized curved surface ceramic-based composite material component is 0.2-1 mm.

[0027] Furthermore, the external frame, the plurality of transverse grilles and the plurality of longitudinal grilles are an integrated structure or a split structure.

[0028] Furthermore, one side panel of the box-type tooling is a detachable structure.

[0029] In addition, the present invention also provides an RMI process method for a large-sized curved surface ceramic matrix composite component, which uses the multi-purpose tooling for the large-sized curved surface ceramic matrix composite component, and is special in that it includes the following steps:

[0030] Step 1, evenly apply boron nitride solution on the surface of the box-shaped tooling, the grid frame and a plurality of shape-correcting baffles, and let them dry;

[0031] Step 2, laying 1 to 2 layers of graphite paper on the bottom of the box-shaped tooling coated with the boron nitride solution;

[0032] Step 3, placing the grid frame coated with the boron nitride solution in a horizontal direction in a box-shaped tooling covered with graphite paper;

[0033] Step 4, spreading silicon powder or silicon-based alloy powder in each powder filling area in the grid frame, making the height of the powder flush with the height of the grid structure, and compacting with a scraper;

[0034] Step 5, placing the large-sized curved surface ceramic-based composite material component on the upper surface of the grid structure, and then inserting one end of the shape-correcting block sheet coated with boron nitride solution into the corresponding card slot, and clamping the large-sized curved surface ceramic-based composite material component on the upper surface of the grid structure through the other end of the shape-correcting block sheet;

[0035] Step 6, spreading silicon powder or silicon-based alloy powder all over the surface of the large-sized curved ceramic-based composite material component, making the upper surface of the laid silicon powder or silicon-based alloy powder flush with the upper surface of the outer frame of the grid frame, and compacting with a scraper;

[0036] Step 7, use a piece of graphite paper to cover the large-sized curved ceramic-based composite material component paved with silicon powder or silicon-based alloy powder, and place it in a crucible and send it into a vacuum furnace for RMI; after the RMI reaction is completed, wait until the temperature drops to room temperature, open the furnace, take out the crucible, and clean up the remaining materials after the reaction.

[0037] Furthermore, in step 4, the ratio of silicon powder or silicon-based alloy powder filled in each powder filling area may be the same or different;

[0038] In step 5, graphite paper is placed at the contact position between the calibration baffle and the large-size curved ceramic-based composite component to ensure clamping.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The present invention provides a multi-purpose tooling for a large-sized curved ceramic-based composite material component, which uses a grid structure that follows the shape of the component to form multiple powder filling areas in the box-type tooling. Each powder filling area can, on the one hand, optimize the flow path of molten silicon or silicon-based alloy, effectively ensuring the infiltration uniformity during RMI, and on the other hand, can separate the powder, which is beneficial to cleaning after RMI and improving the quality of the finished product.

[0041] 2. Compared with the traditional box-type tooling that cannot fit the surface shape of the component and cannot provide stable support for it, the surface shape of the upper surface of the grid structure of the present invention is compatible with the surface shape of the large-size curved ceramic-based composite material component, and the component is pressed against the upper surface of the grid structure through the shaping component, which can enable the grid structure to provide support for the component at high temperature and prevent the component from being deformed due to the gravity of the molten powder on its upper part; at the same time, the shaping component is clamped in cooperation with the card slot, which can not only play a shaping role for the component during RMI, but also can use the tooling of the present invention to shape the component when preparing the matrix using chemical vapor infiltration (CVI) before RMI, effectively improving the process accuracy of the component.

[0042] 3. The multi-purpose tooling for large-sized curved ceramic-based composite material components provided by the present invention can realize the filling of silicon powder or silicon-based alloy powder with different proportions by designing different powder filling areas, thereby realizing directional infiltration in local areas.

[0043] 4. The present invention sets a grid frame in the box-type tooling to separate a plurality of grid structures, which can effectively control the loading amount and improve the loading operation efficiency.

[0044] 5. The grid structure designed in the present invention matches the box-type tooling and can be assembled and disassembled, thereby improving the utilization rate of the box-type tooling. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1It is a structural schematic diagram of a multi-purpose tooling embodiment of a large-sized curved surface ceramic-based composite material component of the present invention (the side panel is made transparent);

[0046] Figure 2 It is a structural schematic diagram of a box-type tooling in an embodiment of the present invention;

[0047] Figure 3 It is a schematic diagram of a state in which a large-sized curved ceramic-based composite material component is placed on the upper surface of the grid structure in an embodiment of the present invention.

[0048] The specific reference numerals are as follows:

[0049] 1-grid frame, 2-shaping baffle, 3-box-type tooling, 4-powder filling area, 5-large-sized curved ceramic-based composite component. DETAILED DESCRIPTION

[0050] In order to make the advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] like Figure 1-3 As shown, a multi-purpose tooling for a large-sized curved surface ceramic-based composite component includes a box-type tooling 3, a grid frame 1, and a shaping component. The box-type tooling 3, the grid frame 1, and the shaping component are all made of materials with good high temperature resistance and thermal conductivity. The box-type tooling 3 is made of graphite, the grid frame 1 can be made of graphite, or carbon material, or carbon composite material, and the shaping component can be made of graphite, or carbon material, or carbon / silicon carbide composite material. In this embodiment, the box-type tooling 3 and the grid frame 1 are made of high-strength graphite material, and the shaping component is made of carbon / silicon carbide composite material.

[0052] The box-type tooling 3 is a box-shaped structure with an open top surface, and the side panels on one side are detachable structures, which can be connected as a whole with screws. The detachable design of the side panels of the box-type tooling 3 is convenient for cleaning and can be reused, thereby improving the utilization rate of the tooling.

[0053] The grid frame 1 includes an external frame, a plurality of transverse grids and a plurality of longitudinal grids. The shape of the external frame matches the shape of the large-sized curved surface ceramic matrix composite material component 5, and the size of the external frame in each direction is 20 to 50 mm larger than the size of the large-sized curved surface ceramic matrix composite material component 5 in the corresponding direction.

[0054] A plurality of equally spaced transverse grids and a plurality of equally spaced longitudinal grids are intersected within the external frame, and the bottoms are flush, so that they are separated by the external frame to form a plurality of grid structures. Among them, the grid structure formed by the external frame is a special-shaped structure, and the grid structure formed by the intersection of two adjacent transverse grids and two adjacent longitudinal grids can be any shape such as a rectangle, a parallelogram, a circle, etc. The grid frame 1 can be an assembly structure of a plurality of transverse grids, a plurality of longitudinal grids and an external frame, or it can be an integrated structure.

[0055] The upper surface of the grid structure matches the surface of the large-sized curved surface ceramic matrix composite component 5. The area of ​​each grid structure is 3% to 8% of the area of ​​the large-sized curved surface ceramic matrix composite component 5, and the width of the grid structure is 1% to 3% of its circumference, which can ensure the uniformity of component penetration.

[0056] The top of the external frame is higher than the top of the transverse grille and the longitudinal grille, and both ends of the transverse grille and the longitudinal grille connected to the external frame are respectively provided with upward flanges; a radial groove is opened on the inner side of the flange near the upper surface of the grille structure, and the height of the groove is 2 to 5 mm; the distance between the bottom surface of each groove and the upper surface of the corresponding grille structure is equal to the thickness of the corresponding boundary part of the large-size curved ceramic-based composite material component 5.

[0057] The shaping component includes a plurality of shaping baffles 2 that follow the boundary portion of the large-sized curved surface ceramic-based composite material component 5; the thickness of the shaping baffle 2 is adapted to the height of the card slot, and the plurality of shaping baffles 2 are horizontally installed in the corresponding card slots, respectively, for clamping the large-sized curved surface ceramic-based composite material component 5 on the upper surface of the grid structure, and shaping the large-sized curved surface ceramic-based composite material component 5. Among them, the distance between each flange and the corresponding boundary portion of the large-sized curved surface ceramic-based composite material component 5 is 0.2 to 1 mm, which is convenient for placing the large-sized curved surface ceramic-based composite material component 5 on the upper surface of the grid structure. The spacing between two adjacent shaping baffles 2 can be adjusted according to the size of the large-sized curved surface ceramic-based composite material component 5 to ensure the shaping effect of the parts; the spacing between two adjacent shaping baffles 2 in the present invention is 100 to 250 mm. The length L1 and width W1 of the shape-correcting baffle 2 are respectively: L1=W2+10-20 mm, W1=D+10-20 mm, wherein W2 is the width of the transverse grid or the longitudinal grid, and D is the depth of the slot.

[0058] The grid frame 1 is laid horizontally in the box-shaped fixture 3, and the grid structure cooperates with the bottom of the box-shaped fixture 3 to form a powder filling area 4. The minimum height of the transverse grid and the longitudinal grid is 15-40 mm, which is used to ensure the minimum filling height of the powder filling area 4. The powder ratio filled in each powder filling area 4 can be the same or different, which is used to achieve directional infiltration in a local area.

[0059] Based on the above multi-purpose tooling for large-sized curved surface ceramic matrix composite components, the present invention also provides an RMI process method for large-sized curved surface ceramic matrix composite components, which specifically includes the following steps:

[0060] Step 1, prepare a large-sized curved ceramic-based composite component 5 that needs to be RMIed; connect and assemble the side panels and the main body of the box-type tooling 3 through bolts and nuts, and evenly apply boron nitride solution on the surfaces of the box-type tooling 3, the grid frame 1 and the correction component, and wait for them to dry naturally.

[0061] Step 2: After drying, lay 1 to 2 layers of graphite paper on the bottom of the box-shaped tooling 3 coated with the boron nitride solution.

[0062] Step 3: Place the grid frame 1 coated with the boron nitride solution horizontally in a box-shaped tooling 3 covered with graphite paper.

[0063] Step 4, filling the lower layer of powder: the silicon powder or silicon-based alloy powder required for the RMI process is spread over each powder filling area 4 in the grid frame 1, so that the height of the powder is flush with the height of the grid structure, and compacted with a scraper. When filling, the ratio of silicon powder or silicon-based alloy powder filled in each powder filling area 4 can be the same or different, so as to achieve directional infiltration in a local area.

[0064] Step 5, place the large-sized curved surface ceramic-based composite material component 5 on the upper surface of the grid structure, then install one end of the shape-correcting stopper 2 coated with boron nitride solution into the corresponding card slot, and clamp the large-sized curved surface ceramic-based composite material component 5 on the upper surface of the grid structure through the other end of the shape-correcting stopper 2. If the thickness of the large-sized curved surface ceramic-based composite material component 5 at the position where it contacts the shape-correcting stopper 2 is slightly smaller than the preset size, graphite paper can be placed at the contact position between the shape-correcting stopper 2 and the large-sized curved surface ceramic-based composite material component 5 to ensure the clamping effect.

[0065] Step 6, filling the upper layer of powder: spread the silicon powder or silicon-based alloy powder required for the RMI process on the surface of the large-sized curved ceramic-based composite material component 5, so that the upper surface of the laid silicon powder or silicon-based alloy powder is flush with the upper surface of the outer frame of the grid frame 1, and compact it with a scraper.

[0066] Step 7, use a piece of graphite paper to cover the large-sized curved ceramic-based composite material component 5 with silicon powder or silicon-based alloy powder, and place it in a crucible and send it into a vacuum furnace for RMI; after the RMI reaction is completed, wait until the temperature drops to room temperature, open the furnace, take out the crucible, and clean up the remaining material after the reaction.

[0067] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. For ordinary professional and technical personnel in the field, the specific technical solution recorded in the above embodiment can be modified, or some of the technical features therein can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution protected by the present invention.

Claims

1. A multi-purpose tool for large-sized curved surface ceramic matrix composite components, characterized by: It comprises a box-shaped tool (3), a grid frame (1) and a shaping component; The box-shaped tooling (3) is a box-shaped structure with an open top surface; The grid frame (1) comprises an external frame, a plurality of transverse grids and a plurality of longitudinal grids; The shape of the external frame is compatible with the shape of the large-sized curved surface ceramic-based composite material component (5), and the dimension of the external frame in each direction is 20 to 50 mm larger than the dimension of the large-sized curved surface ceramic-based composite material component (5) in the corresponding direction; A plurality of equally spaced transverse grids and a plurality of equally spaced longitudinal grids are intersected and located within the external frame, and the bottoms are flush, so that a plurality of grid structures are formed within the external frame; the upper surface shape of the grid structure is adapted to the surface shape of the large-sized curved surface ceramic-based composite material component (5); The top of the external frame is higher than the top of the transverse grid and the longitudinal grid, and both ends of the transverse grid and the longitudinal grid connected to the external frame are respectively provided with upward flanges; a slot is radially provided at a position close to the upper surface of the grid structure on the inner side of the flange, and the distance between the bottom surface of each slot and the upper surface of the corresponding grid structure is equal to the thickness of the corresponding part of the large-size curved surface ceramic-based composite material component (5); The shaping component comprises a plurality of shaping baffles (2) conforming to the boundary portion of the large-sized curved surface ceramic-based composite material component (5); the plurality of shaping baffles (2) are respectively installed horizontally in corresponding slots and are used to clamp the large-sized curved surface ceramic-based composite material component (5) onto the upper surface of the grid structure; The grid frame (1) is arranged in the box-shaped tooling (3) along the horizontal direction, and the grid structure cooperates with the bottom of the box-shaped tooling (3) to form a powder filling area (4).

2. The multi-purpose tooling for large-sized curved surface ceramic matrix composite components according to claim 1, characterized in that: The box-shaped tooling (3) is made of graphite; The outer frame, transverse grid and longitudinal grid of the grid frame (1) are all made of graphite, or carbon material, or carbon / silicon carbide composite material; The shape correction piece (2) is made of graphite, or carbon material, or carbon / silicon carbide composite material.

3. The multi-purpose tooling for large-sized curved surface ceramic matrix composite components according to claim 2, characterized in that: The area of ​​each grid structure is 3% to 8% of the area of ​​the large-size curved surface ceramic-based composite material component (5), and the width of the grid structure is 1% to 3% of its circumference.

4. The multi-purpose tooling for large-sized curved surface ceramic matrix composite components according to claim 3, characterized in that: The height of the card slot is 2 to 5 mm; The distance between two adjacent shaping baffles (2) is 100 to 250 mm; The length L1 and width W1 of the shaping baffle (2) are respectively: L1=W2+10~20mm W1=D+10~20mm Wherein, W2 is the width of the transverse grille or the longitudinal grille, and D is the depth of the slot.

5. The multi-purpose tooling for large-sized curved surface ceramic matrix composite components according to claim 4, characterized in that: The minimum height of the transverse grid is 15 to 40 mm; The minimum height of the longitudinal grid is 15-40 mm.

6. The multi-purpose tooling for large-sized curved surface ceramic matrix composite components according to claim 5, characterized in that: The distance between the plurality of flanges and the corresponding boundary portion of the large-sized curved surface ceramic-based composite material component (5) is 0.2 to 1 mm.

7. The multi-purpose tooling for large-sized curved surface ceramic matrix composite components according to claim 1, characterized in that: The external frame, the plurality of transverse grids and the plurality of longitudinal grids are an integrated structure or a split structure.

8. The multi-purpose tooling for large-sized curved surface ceramic matrix composite components according to claim 1, characterized in that: One side plate of the box-shaped tooling (3) is a detachable structure.

9. An RMI process for a large-sized curved surface ceramic matrix composite component, using the multi-purpose tooling for a large-sized curved surface ceramic matrix composite component according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1, evenly brushing boron nitride solution on the surfaces of the box-shaped tooling (3), the grid frame (1) and the plurality of shape-correcting baffles (2), and drying them; Step 2, laying 1 to 2 layers of graphite paper on the bottom of the box-shaped tooling (3) coated with the boron nitride solution; Step 3, placing the grid frame (1) coated with the boron nitride solution in a horizontal direction in a box-shaped tooling (3) covered with graphite paper; Step 4, spreading silicon powder or silicon-based alloy powder over each powder filling area (4) in the grid frame (1) so that the height of the powder is flush with the height of the grid structure, and compacting with a scraper; Step 5, placing the large-sized curved surface ceramic-based composite material component (5) on the upper surface of the grid structure, and then inserting one end of the shape-correcting block sheet (2) coated with a boron nitride solution into the corresponding card slot, and clamping the large-sized curved surface ceramic-based composite material component (5) on the upper surface of the grid structure through the other end of the shape-correcting block sheet (2); Step 6, spreading silicon powder or silicon-based alloy powder all over the surface of the large-sized curved ceramic-based composite material component (5), making the upper surface of the laid silicon powder or silicon-based alloy powder flush with the upper surface of the outer frame of the grid frame (1), and compacting with a scraper; Step 7, using a piece of graphite paper to cover the large-sized curved ceramic-based composite material component (5) on which silicon powder or silicon-based alloy powder is laid, and placing it in a crucible and sending it into a vacuum furnace for RMI; after the RMI reaction is completed, wait for the temperature to drop to room temperature, open the furnace, take out the crucible, and clean up the residual material after the reaction.

10. The RMI process for large-sized curved ceramic matrix composite components according to claim 9, characterized in that: In step 4, the ratio of silicon powder or silicon-based alloy powder loaded in each powder loading area (4) may be the same or different; In step 5, graphite paper is placed at the contact position between the shape-correcting baffle (2) and the large-sized curved surface ceramic-based composite material component (5) to ensure clamping.

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