Simplified block shaper for chemical vapor infiltration

Abstract

The invention relates to a load (1004) for chemical vapor infiltration comprising one or more fiber preforms (4) and a shaper (100) comprising a plurality of shaping blocks (150) arranged in contact with one of the fiber preforms (4), the load (1004) being characterized in that it comprises at least two shells (110, 120) arranged opposite one another, each of the shells comprising at least one receiving portion (110b, 120b) for receiving the shaping blocks (150), the shaping blocks (150) being arranged in contact with one of the receiving portions (110b, 120b) of the shells (110, 120), the shells (110, 120) being brought closer to one another by clamping means (160) such that the shaping blocks (150) are pressed against the one or more fiber preforms (4) by the shells (110, 120).

Description

Description Title of the invention: Simplified block former for gaseous infiltration Technical Field

[0001] The present invention relates to the gaseous infiltration of fibrous preforms, for example the chemical gaseous infiltration of fibrous preforms, and in particular the conformer receiving the fibrous preform(s) for gaseous infiltration. Previous technique

[0002] To obtain lightweight turbomachine components with excellent thermomechanical properties, composite materials are commonly used. The use of composite materials helps optimize turbomachine performance, notably by reducing the overall mass of the turbomachine, which contributes to lower fuel consumption and therefore a significant reduction in pollutant emissions. Furthermore, due to their superior resistance to high temperatures, ceramic matrix composite materials require less cooling. Since this cooling is traditionally drawn from the compressor, impacting turbomachine efficiency, ceramic matrix composite materials further improve engine efficiency and reduce fuel consumption even more.

[0003] In particular, it is known to produce a fibrous texture by weaving, for example on a Jacquard loom. The fibrous texture coming off the loom is then cut to obtain a fiber blank. This fiber blank is then shaped in a former to create a fibrous preform, which is intended to form the fibrous reinforcement of the composite part to be produced. The fibrous preform in the former is then consolidated. Consolidation can be carried out conventionally by gaseous infiltration, for example by chemical vapor infiltration (CVI). When consolidation is complete, the consolidated fibrous preform is removed from the conformer and then densified by a matrix in one or more stages.

[0004] The former used in such a process often has a complex design. Typically, the former consists of a frame onto which a number of blocks are mounted and bolted to define a cavity shaped like the desired fibrous preform. The blocks are assembled one by one around the fibrous blank, progressively shaping it until the desired fibrous preform is obtained. Such a former, including the blocks and their fastening systems, is very bulky. Furthermore, positioning the former around the fibrous blank requires numerous and time-consuming manual operations. Description of the invention

[0005] To overcome the aforementioned drawbacks, the invention proposes a simplified and easy-to-assemble former.

[0006] To this end, the invention proposes a gaseous infiltration loading comprising one or more fibrous preforms and a conformer receiving the fibrous preform(s), the conformer comprising a plurality of conforming blocks each comprising at least one conforming surface disposed in contact with one of the fibrous preforms, the conforming surfaces of the conforming blocks forming one or more cavities having the shape of the fibrous preform(s) and receiving the fibrous preform(s), the loading being characterized in that it further comprises at least two shells disposed opposite each other each comprising at least one portion receiving the conforming blocks, the conforming blocks further comprising at least one blocking surface disposed in contact with one of the portions receiving the shells,The shells are brought together by means of bracing so that the conformation blocks are held against the fibrous preform(s) by the shells.

[0007] Thus, the use of shells to hold the conformation blocks in place makes it possible to use conformation blocks without means of fixation. Thus, the former is lighter and less bulky, but also easier and faster to set up. Furthermore, because the system for holding the fiber preform is simplified, gas access to the fiber preform is improved. The invention also proposes a conformer for gaseous infiltration intended to receive at least one fibrous preform, the conformer comprising a plurality of conforming blocks each comprising at least one conforming surface configured to be in contact with the fibrous preform(s), the conforming surface having a shape complementary to the shape of one of the portions of the fibrous preform(s), the conformer being characterized in that it further comprises at least two shells arranged opposite each other each comprising at least one portion for receiving the conforming blocks, the conforming blocks further comprising at least one blocking surface configured to be in contact with one of the portions for receiving the shells, the conformer further comprising clamping means configured to bring the shells closer together,so that when the conformer accommodates one or more fibrous preforms, the conforming surfaces of the conforming blocks form one or more cavities having the shape of the fibrous preform(s) and accommodating the fibrous preform(s), and the conforming blocks are held against the fibrous preform(s) by the shells.

[0008] According to a particular embodiment of the invention, the fibrous preform(s) are stiffened.

[0009] Positioning the conformer around the fiber preform is very difficult with a conventional fiber preform, which is too flexible and deforms easily. Therefore, it is strongly recommended to stiffen the fiber preform before positioning the conformer to obtain the loading according to the invention. Once the properly stiffened fiber preform is positioned in the conformer, it can be unstiffened. The loading, including the unstiffened fiber preform, is also included in the present invention.

[0010] The fibrous preform(s) can be stiffened by a hardened fugitive resin. The fibrous preform(s) can also be stiffened by impregnation with a fluid and freezing of said fluid, said fluid being, for example, water.

[0011] According to another particular embodiment of the invention, the clamping means are positioned on a peripheral portion of the shells located around the receiving portion or portions.

[0012] Thus, the clamping devices do not impede gas flow. The clamping devices are also simpler to implement, as the shaping blocks do not interfere with their installation.

[0013] According to another particular embodiment of the invention, the receiving portions of at least a part of the shells comprise transverse channels for the circulation of gas opening onto the outside of the conformer.

[0014] Thus, gases can penetrate the feed through these transverse channels to improve the amount of gas delivered to the fibrous preform(s). This characteristic applies to the end shells of the former when the former includes intermediate shells located between the end shells.

[0015] According to another particular embodiment of the invention, the loading, or conformer, is formed by a stacking in the order following a stacking direction of at least one first end shell, one or more intermediate shells, and a second end shell, the intermediate shell(s) comprising a first face disposed opposite an end shell or another intermediate shell and a second face opposite the first face disposed opposite an end shell or another intermediate shell, the first face and the second face of the intermediate shell(s) comprising one or more portions for receiving the conformation blocks.

[0016] Thus, the loading according to the invention can accommodate a larger number of fibrous preforms while maintaining relatively compact dimensions.

[0017] According to another particular embodiment of the invention, transverse channels for the circulation of gas connect the receiving portions of the first face to the receiving portions of the second face of the intermediate shell(s).

[0018] Such transverse channels improve gas circulation within the load, and in particular improve gas exposure of the fibrous preforms located in the center of the load.

[0019] According to another particular embodiment of the invention, longitudinal channels for gas circulation extend inside the intermediate shell(s) at a non-zero distance from the first and second faces of the intermediate shell(s), the longitudinal channels being connected to the transverse channels. Preferably, each longitudinal channel is connected to at least two transverse channels.

[0020] Such longitudinal channels improve gas circulation within the load, and in particular improve gas exposure of fibrous preforms located in the center of the load and in parts of the load furthest from the gas inlet.

[0021] The longitudinal channels can be through-channels, opening outside the cargo. In this case, the longitudinal channels provide an additional entry point for the gases, allowing them to penetrate the cargo more easily.

[0022] According to another particular embodiment of the invention, the loading, or conformer, extends between a main gas inlet surface and a main gas outlet surface along a main gas flow direction perpendicular to the stacking direction, wherein the intermediate shell(s) comprise a plurality of internal chambers extending at a non-zero distance from the first and second faces of the intermediate shell(s), the internal chambers of the same intermediate shell being distributed in a column extending along the main gas flow direction, a plurality of transverse channels opening into each internal chamber, each internal chamber comprising at least one gas inlet port disposed on the main gas inlet surface.

[0023] Thus, each internal chamber is supplied with gas independently of the other internal chambers. Therefore, even fibrous preforms located far from the main gas inlet surface can be properly supplied with gas.

[0024] The invention also relates to a method for preparing a load intended to be placed in a gaseous infiltration installation, said load comprising one or more fibrous preforms arranged in a conformer, the method comprising:

[0025] - the shaping of one or more fibrous blanks into one or more fibrous preforms in a shaping mold,

[0026] - the stiffening of the fibrous preform(s) in the shaping mold,

[0027] - the removal of the rigidified fibrous preform(s) from the shaping mold,

[0028] - the placement of the stiffened fibrous preform(s) in a conformer so as to obtain a load as described above,

[0029] - the de-rigidification of the fibrous preform(s) arranged in the conformer.

[0030] The invention further relates to a gaseous infiltration method comprising:

[0031] - the preparation of a load in accordance with the process as described above,

[0032] - the arrangement of the load in a gaseous infiltration installation, then

[0033] - the infiltration by gaseous means of the fibrous preform(s) of the loading.

[0034] In particular, it may involve chemical infiltration in the gaseous phase. Brief description of the drawings

[0035] [Fig. 1] Figure 1 is an exploded perspective view of a load according to the invention.

[0036] [Fig. 2] Figure 2 is a perspective view of the closed load of Figure 1.

[0037] [Fig. 3] Figure 3 is an exploded perspective view of another load according to the invention comprising a plurality of fibrous preforms.

[0038] [Fig. 4] Figure 4 is a perspective view of the closed load of Figure 3.

[0039] [Fig. 5] Figure 5 is an exploded perspective view of another load according to a variant of the load in Figures 3 and 4.

[0040] [Fig. 6] Figure 6 is an exploded perspective view of another load according to the invention comprising more than two shells.

[0041] [Fig. 7] Figure 7 is a cross-sectional view of the load in Figure 6.

[0042] [Fig. 8] Figure 8 is a cross-sectional view of another loading according to a variant of the loading in Figures 6 and 7.

[0043] [Fig. 9] Figure 9 is a cross-sectional view of another loading according to another variant of the loading of Figures 6 and 7.

[0044] [Fig. 10] Figure 10 is a flowchart illustrating a method for preparing a load according to the invention. Description of the implementation methods

[0045] Figures 1 and 2 illustrate an example of loading 1004 according to the invention.

[0046] The loading 1004 comprises a conformer 100 receiving a fibrous preform. The fibrous preform may be a stiffened fibrous preform 4, as illustrated in Figures 1 and 2. However, it does not depart from the scope of the invention if the loading comprises a de-stiffened fibrous preform 5, as described later.

[0047] The former 100 comprises a first shell 110 and a second shell 120 arranged opposite each other. The first shell 110 and the second shell 120 are arranged opposite each other along a flange direction DB.

[0048] The stiffened fibrous preform 4 is arranged between the first shell 110 and the second shell 120.

[0049] A plurality of conformation blocks 150 are present between the first shell 110 and the second shell 120. Thus, the conformation blocks 150 are arranged between the first shell 110 and the second shell 120 along the DB bridle direction. The conformation blocks 150 are without any means of attachment.

[0050] The first shell 110 includes a receiving portion 110b. The receiving portion 110b is configured to be in contact with the conformation blocks 150. The receiving portion 110b can also be in contact with the fibrous preform 4. Conversely, the first shell 110 can be maintained at a non-zero distance from the fibrous preform 4 by the conformation blocks 150. The first shell 110 is then not in contact with the fibrous preform 4. The first shell 110 further includes a peripheral portion 110c surrounding the receiving portion 110b.

[0051] The second shell 120 includes a receiving portion 120b. The receiving portion 120b is configured to be in contact with the conformation blocks 150. The receiving portion 120b can also be in contact with the fibrous preform 4. Conversely, the second shell 120 can be maintained at a non-zero distance from the fibrous preform 4 by the conformation blocks 150. The second shell 120 is then not in contact with the fibrous preform 4. The second shell 120 further includes a peripheral portion 120c surrounding the receiving portion 120b.

[0052] The 150 conformation blocks include at least one 150a conformation face configured to be in contact with the fibrous preform 4. The 150a conformation faces of the 150 conformation blocks have a shape complementary to the shape of one of the portions of the fibrous preform 4. When the fibrous preform 4 is mounted in the conformer 100, the conformation faces 150a of the conformation blocks 150 are in contact with the fibrous preform 4.

[0053] The conformation blocks 150 also include at least one blocking face 150b configured to be in contact with at least one of the shells 110, 120. In particular, the blocking faces 150b of the conformation blocks 150 are configured to be in contact with the receiving portion 110b, 120b of at least one of the shells 110, 120.

[0054] The receiving portions 110b, 120b preferably include lateral edges 110b, 120b delimiting said receiving portion 110b, 120b. The lateral edges are configured to be in contact with the blocking faces 150b of the conformation blocks 150.

[0055] Preferably, at least part of the lateral edges of the receiving portions 110b, 120b are inclined relative to the clamping direction DB. This improves the blocking of the conformation blocks 150 of the load 1004. The inclination of at least part of the lateral edges of the receiving portions 110b, 120b relative to the clamping direction DB is preferably combined with an inclination of at least part of the blocking faces 150b of the conformation blocks 150 relative to the clamping direction DB. Thus, the blocking faces 150b inclined relative to the clamping direction DB cooperate with the lateral edges inclined relative to the clamping direction DB to improve the blocking of the conformation blocks 150 by the shells 110, 120.

[0056] The receiving portions 110b and 120b may include a base 120ba. The base extends transversely to the clamping direction DB. Preferably, the base extends perpendicularly to the clamping direction DB. If the receiving portions 110b and 120b include a base, any lateral edges extend from the base. The base is configured to be in contact with at least a portion of the blocking faces 150b of the conformation blocks 150.

[0057] Reception areas 110b and 120b can also be bottomless. In this case, the side edges define a through opening following the DB bridle direction. The 110b and 120b reception areas can then be formed by the lateral edges. If there is no base, it is strongly recommended that at least part of the lateral edges be inclined relative to the DB bridle direction to facilitate the locking of the forming blocks.

[0058] The first and second shells may have a base. The first and second shells may have no base. In one variant, only one of the shells may have a base. In the example shown in Figures 1 and 2, the second shell 120 has a base and the first shell 110 has no base.

[0059] The presence of a base improves the retention of 150-shaped blocks in the load. However, the presence of a base restricts gas flow when the load is placed in a gaseous infiltration system. Therefore, a configuration where only one of the shells has a base is a good compromise.

[0060] The bottom may include transverse channels for gas circulation. These transverse channels preferably extend in the DB bridle direction. The transverse channels are through-channels. The transverse channels open onto the receiving section.

[0061] The conformation blocks 150 preferably include gas circulation channels opening onto the fibrous preform 4. The gas circulation channels of the conformation blocks may be in the form of a channel network. The gas circulation channels of the conformation blocks 150 may be connected to the transverse channels of the bottom of the receiving portion. Each gas circulation channel may be connected to at least one transverse channel of the bottom of the receiving portion.

[0062] Thus, gas circulation in the conformer 100 can be ensured in several ways, alone or in combination. Gases can enter the conformer through the gap between the first shell 110 and the second shell 120 and / or through the transverse channels of the bottom 120ba of one of the receiving portions 120b and / or through the through opening if one of the receiving portions 110b is bottomless. The gases can then be conveyed directly to the fibrous preform 4 and / or via gas circulation channels in the conformation blocks.

[0063] The conformer 100 further includes clamping means 160 configured to bring the first shell 110 closer to the second shell 120. In particular, the clamping means 160 allow the first shell 110 and the second shell 120 to be brought closer together along the clamping direction DB.

[0064] The clamping means 160 are located at the peripheral portion 110c, 120c of the shells 110, 120. Thus, the clamping means 160 do not interfere with the positioning and locking of the forming blocks 150. The clamping means 160 also do not impede gas circulation. Furthermore, the presence of the clamping means 160 at the peripheral portion 110c, 120c of the shells 110, 120 allows the load 1004 to be secured with a reduced number of clamping means 160.

[0065] The clamping means 160 can, for example, be formed by a plurality of holes present on the peripheral portions 110c, 120c of the shells 110, 120 extending along the clamping direction DB and by bolts passing through said holes. The clamping means 160 can, for example, be formed by a plurality of holes present on the peripheral portions 110c, 120c of the shells 110, 120 extending along the clamping direction DB and by studs passing through said holes.

[0066] When the loading 1004 is closed, the first shell 110 and the second shell 210 can be in contact with each other. In particular, the peripheral portions 110c, 120c of the shells 110, 120 can be in contact with each other.

[0067] The loading shown in Figures 1 and 2 comprises a single fibrous preform. To increase the number of fibrous preforms that can be processed by gas infiltration, the invention also proposes loadings with a conformer that accommodates a plurality of fibrous preforms, as illustrated in Figures 3 to 9.

[0068] Figures 3 and 4 illustrate an example of a loading 2004 comprising a conformer 200 accommodating a plurality of stiffened fibrous preforms 4. The fibrous preforms may be stiffened fibrous preforms 4, as illustrated in Figures 3 and 4. However, it does not depart from the scope of the invention if the loading includes de-stiffened fibrous preforms 5, as described later.

[0069] The former 200 comprises a first shell 210 and a second shell 220 arranged opposite each other. The first shell 210 and the second shell 220 are arranged opposite each other along a flange direction DB.

[0070] The stiffened fibrous preforms 4 are arranged between the first shell 210 and the second shell 220.

[0071] A plurality of conformation blocks 250 are present between the first shell 210 and the second shell 220. Thus, the conformation blocks 250 are arranged between the first shell 210 and the second shell 220 along the DB bridle direction. The conformation blocks 250 are without any means of attachment.

[0072] The first shell 210 comprises a plurality of receiving portions (not visible in Figures 3 and 4) configured to each receive a fibrous preform 4. The receiving portions are configured to be in contact with the conformation blocks 250. The receiving portions may also be in contact with the fibrous preforms 4. Conversely, the first shell 210 may be maintained at a non-zero distance from the fibrous preforms 4 by the conformation blocks 250. The first shell 210 is then not in contact with the fibrous preforms 4. The first shell 210 further comprises a peripheral portion surrounding the receiving portions and connecting the receiving portions to each other.

[0073] The first shell 210 comprises a first face 211 and a second face 212 opposite the first face 211. The first face 211 and the second face 212 are opposite along the DB bridle direction. The reception portions are present on the first face 211.

[0074] The second shell 220 comprises a plurality of receiving portions 220b, each configured to receive a fibrous preform 4. The receiving portions 220b are configured to be in contact with the conformation blocks 250. The receiving portions may also be in contact with the fibrous preforms 4. Alternatively, the second shell 220 may be maintained at a non-zero distance from the fibrous preforms 4 by the conformation blocks 250. In this case, the second shell 220 is not in contact with the fibrous preforms 4. The second shell 220 further comprises a peripheral portion 220c surrounding the receiving portions 220b and connecting the receiving portions 220b to each other.

[0075] The second shell 220 comprises a first face 221 and a second face 222 opposite the first face 221. The first face 221 and the second face 222 are opposite along the flange direction DB. The receiving portions 2220b are present on the second face 222. The first face 211 of the first shell 210 is arranged opposite the second face 222 of the second shell 222.

[0076] The conformation blocks 250 include at least one conformation face configured to be in contact with the fibrous preforms 4. The conformation faces of the conformation blocks 250 have a shape complementary to the shape of one of the portions of the fibrous preforms 4. When the fibrous preforms 4 are mounted in the conformer 200, the conformation faces of the conformation blocks 250 are in contact with the fibrous preforms 4.

[0077] The conformation blocks 250 also include at least one blocking face 250b configured to be in contact with at least one of the shells 210, 220. In particular, the blocking faces 250b of the conformation blocks 250 are configured to be in contact with one of the receiving portions 220b of one of the shells 210, 220.

[0078] The receiving portions 220b of the shells 210, 220 preferably include lateral edges delimiting said receiving portion 220b. The lateral edges are configured to be in contact with the blocking faces 250b of the conformation blocks 250.

[0079] Preferably, at least part of the lateral edges of the receiving portions 220b are inclined relative to the clamping direction DB. This improves the blocking of the conformation blocks 250 of the load 2004. The inclination of at least part of the lateral edges of the receiving portions 220b relative to the clamping direction DB is preferably combined with an inclination of at least part of the blocking faces 250b of the conformation blocks 250 relative to the clamping direction DB. Thus, the blocking faces 250b inclined relative to the clamping direction DB cooperate with the lateral edges inclined relative to the clamping direction DB to improve the blocking of the conformation blocks 250 by the shells 210, 220.

[0080] The 220b receiving portions may include a base. The base extends transversely to the DB clamping direction. Preferably, the base extends perpendicularly to the DB clamping direction. If the 220b receiving portions include a base, any lateral edges extend from the base. The base is configured to be in contact with at least a portion of the 250b blocking faces of the 250 conformation blocks.

[0081] Preferably, the bottom includes transverse channels 210a for gas circulation. The transverse channels 210a preferably extend along the bridle direction DB. The transverse channels 210a are through channels. The transverse channels 210a open onto one of the receiving portions 220b of one of the shells 210, 220. In particular, each transverse channel 210a opens onto one of the receiving portions 220b of one of the shells 210, 220. The transverse channels 210a extend from the first face 211, 221 to the second face 212, 222 of the shells 210, 220.

[0082] The 250 conformation blocks preferably include gas circulation channels opening onto the fibrous preform 4. The gas circulation channels of the conformation blocks may be in the form of a channel network. The gas circulation channels of the 250 conformation blocks may be connected to the transverse channels of the bottom of the receiving portion. Each gas circulation channel may be connected to at least one transverse channel of the bottom of the receiving portion.

[0083] The 220b receiving portions may also be bottomless. In this case, the lateral edges define a through opening along the DB bridle direction. This through opening leads to the first face 211, 221 and the second face 212, 222 of the shell 210, 220. The 220b receiving portions can then be formed by the lateral edges. If there is no bottom, it is strongly recommended that at least part of the lateral edges be inclined relative to the DB bridle direction to facilitate the locking of the forming blocks.

[0084] The first and second shells may have a base. The first and second shells may have no base. In one variant, only one of the shells may have a base. In the example shown in Figures 3 and 4, shells 210 and 220 each have a base.

[0085] The presence of a base improves the retention of 250-shaped blocks in the load. However, the presence of a base restricts gas flow when the load is placed in a gaseous infiltration system. Therefore, a configuration where only one of the shells has a base is a good compromise.

[0086] The former 200 further includes clamping means 260 configured to bring the first shell 210 closer to the second shell 220. In particular, the clamping means 260 make it possible to bring the first shell 210 and the second shell 220 closer together along the clamping direction DB.

[0087] The clamping means 260 are located at the peripheral portion 220c of the shells 210, 220. Thus, the clamping means 260 do not interfere with the positioning and locking of the forming blocks 250. The clamping means 260 also do not impede gas circulation. Furthermore, the presence of the clamping means 260 at the peripheral portion 220c of the shells 210, 220 allows the load 2004 to be secured with a reduced number of clamping means 160.

[0088] The clamping means 260 can, for example, be formed by a plurality of orifices present on the peripheral portions 220c of the shells 210, 220 extending along the clamping direction DB and by bolts passing through said orifices. The clamping means 260 can, for example, be formed by a plurality of orifices present on the peripheral portions 220c of the shells 210, 220 extending along the clamping direction DB and by studs passing through said orifices.

[0089] The receiving portions 220b can be arranged in rows and columns. In the example shown in Figures 3 and 4, each shell 210, 220 comprises two rows of receiving portions 220b and four columns of receiving portions 220b. Thus, the loading 2004 can comprise two rows of fibrous preforms 4 and four columns of fibrous preforms 4. Preferably, the loading 2004 comprises at least two rows and two columns of fibrous preforms 4. Thus, each shell 210, 220 preferably comprises at least two rows and two columns of receiving portions 220b.

[0090] To improve the positioning of the first shell 210 relative to the second shell 220, the peripheral portions 220c of the shells 210 and 220 may have a crenellated or serrated shape. The peripheral portion of the first shell 210 has a geometry complementary to the peripheral portion 220c of the second shell 220. Each crenellation or tooth carries one or more receiving portions 220b. Preferably, each crenellation or tooth carries one or more complete columns of receiving portions 220. In particular, each crenellation or tooth carries a single complete column of receiving portions 220b. Thus, the peripheral portions 220c of the shells 210 and 220 have flat portions inclined with respect to the flange direction DB, each flat portion hosting one or more receiving portions 220b, the flat portions being separated by flat supports 210d, 220d transverse to the flat portions.Preferably, each flat portion accommodates one or more whole columns of 220b receiving portions. In particular, in the example illustrated in Figures 3 and 4, each flat portion accommodates a single whole column of 220b receiving portions.

[0091] Figure 5 illustrates a variant of Figures 3 and 4, in which a loading 3004 comprises a conformer 300 accommodating a plurality of stiffened fibrous preforms 4. The fibrous preforms can be stiffened fibrous preforms 4, as illustrated in Figure 5. However, it does not depart from the scope of the invention if the loading includes de-stiffened fibrous preforms 5, as described later.

[0092] The conformer 300 comprises the second shell 220 as described in relation to figures 3 and 4 and a plurality of first shells 310. The first shells 311, 312, 313, 314 are arranged opposite the second shell 220. The first shells 311, 312, 313, 314 are arranged opposite the second shell 220 along the bridle direction DB.

[0093] In the example illustrated in Figure 5, the conformer 300 includes four first shells 310. We do not, of course, go out of bounds if the conformer includes two or three first shells or more than four first shells.

[0094] The stiffened fibrous preforms 4 are arranged between the first shells 310 and the second shell 220.

[0095] The plurality of conformation blocks 250 described in relation to Figures 3 and 4 is present between the first shells 310 and the second shell 220. Thus, the conformation blocks 250 are arranged between the first shells 310 and the second shell 220 along the bridle direction DB. Each conformation block 250 is located between a first shell 311, 312, 313, 314 and the second shell 220.

[0096] The first shells 310 comprise a plurality of receiving portions (not visible in Figure 5) configured to each receive a fibrous preform 4. Each first shell 311, 312, 313, 314 comprises at least one receiving portion. The receiving portions are configured to be in contact with the conformation blocks 250. The receiving portions may also be in contact with the fibrous preforms 4. Alternatively, the first shells 311, 312, 313, 314 may be held at a non-zero distance from the fibrous preforms 4 by the conformation blocks 250. The first shells 311, 312, 313, 314 are then not in contact with the fibrous preforms 4. The first shells 311, 312, 313, 314 further each comprise a peripheral portion surrounding the portions of reception, and linking the reception portions to each other if the first shell includes more than one reception portion.

[0097] Each first shell 311, 312, 313, 314 comprises a first face and a second face opposite the first face. The first and second faces are oriented oppositely along the flange direction DB. The receiving portion(s) of each first shell 311, 312, 313, 314 are present on the first face. The first faces of the first shells 311, 312, 313, 314 are positioned opposite the second face 222 of the second shell 222.

[0098] The receiving portions of the first shells 311, 312, 313, and 314 preferably include lateral edges delimiting said receiving portion. The lateral edges are configured to be in contact with the blocking faces 250b of the conformation blocks 250. Preferably, at least a portion of the lateral edges of the receiving portions are inclined relative to the clamping direction DB. Thus, the clamping of the conformation blocks 250 of the load 3004 is improved. The inclination relative to the clamping direction DB of at least a portion of the lateral edges of the receiving portions is preferably associated with an inclination of at least a portion of the blocking faces 250b of the conformation blocks 250 relative to the clamping direction DB.Thus, the blocking faces 250b inclined with respect to the clamping direction DB cooperate with the lateral edges inclined with respect to the clamping direction DB to improve the blocking of the conformation blocks 250 by the first shells 310.

[0099] The receiving portions of the first 310 shells may include a bottom. The bottom extends transversely to the DB bridle direction. Preferably, the bottom extends perpendicularly to the DB bridle direction. If the receiving portions include a bottom, any lateral edges extend from the bottom. The bottom is configured to be in contact with at least a portion of the 250b blocking faces of the 250 conformation blocks.

[0100] Preferably, the bottom of the receiving portions of the first shells 310 includes transverse channels 310a for gas circulation. The transverse channels 310a preferably extend along the bridle direction DB. The transverse channels 310a are through channels. The transverse channels 310a open onto one of the reception portions of one of the first shells 310. In particular, each transverse canal 310a opens onto one of the reception portions of one of the first shells 310. The transverse canals 310a extend from the first face to the second face of the first shell 310.

[0101] The receiving portions of the first 310 shells can also be bottomless. In this case, the lateral edges define a through opening along the DB bridle direction. This through opening leads to the first and second faces of the first 310 shells. The receiving portions can then be formed by the lateral edges. If there is no bottom, it is strongly recommended that at least part of the lateral edges be inclined relative to the DB bridle direction to facilitate the locking of the forming blocks.

[0102] The former 300 further includes clamping means 360 configured to bring the first shells 310 closer to the second shell 220. In particular, the clamping means 360 allow the first shells 310 and the second shell 220 to be brought together along the clamping direction DB.

[0103] The clamping means 360 are located at the peripheral portion of the first shells 310 and the second shell 320. Thus, the clamping means 360 do not interfere with the positioning and locking of the forming blocks 250. The clamping means 360 also do not impede gas flow. The clamping means 360 may have the same characteristics as the clamping means described previously.

[0104] In this variant, the receiving portions can also be arranged in rows and columns. Preferably, the loading 3004 comprises at least two rows and two columns of fibrous preforms 4. Thus, the second shell 220 preferably comprises at least two rows and two columns of receiving portions 220b. Preferably, each first shell 310 comprises at least one full column of receiving portions or at least one full row of receiving portions. In particular, each first shell 310 comprises a single full column of receiving portions or a single full row of receiving portions.

[0105] To improve the positioning of the first shells 310 relative to the second shell 220, the peripheral portions 220c of the second shell 220 may have a crenellated or serrated shape as described previously. Each crenellation or tooth corresponds to one of the first shells 310. Preferably, each first shell 310 is in contact with only one crenellation or tooth.

[0106] The loads in Figures 1 to 5 comprise only two superimposed shells along the DB clamping direction. In order to increase the number of fibrous preforms that can be treated by gas infiltration, the invention also proposes loads of at least three superimposed shells along the DB clamping direction accommodating a plurality of fibrous preforms, as in the examples illustrated in Figures 6 to 9.

[0107] Figures 6 and 7 illustrate an example of a load 4004 comprising at least three stacked shells along the clamping direction DB, also known as the stacking direction. In the example shown in Figures 6 and 7, the load 4004 comprises four stacked shells 410, 420, 430, and 440. Of course, the invention remains within the scope of the load if it comprises only three stacked shells, or if it comprises five or more stacked shells along the clamping direction DB.

[0108] The loading 4004 includes a conformer 400 accommodating a plurality of stiffened fibrous preforms 4. The fibrous preforms can be stiffened fibrous preforms 4, as illustrated in Figures 6 and 7. However, it does not depart from the scope of the invention if the loading includes de-stiffened fibrous preforms 5, as described later.

[0109] The former 400 comprises a stack of several shells arranged in the DB clamping direction. The former 400 comprises, in the order of stacking, a first end shell 410, a first intermediate shell 420, a second intermediate shell 430, and a second end shell 440. The shells 410, 420, 430, and 440 are stacked in the DB clamping direction. Each shell comprises at least one receiving portion and one peripheral portion, the reception portion(s) and the peripheral portion having the same characteristics as before.

[0110] A plurality of 450 conformation blocks is arranged between the 410, 420, 430, 440 shells. The 450 conformation blocks may exhibit the same characteristics as the conformation blocks described previously. [YES] Each 410, 420, 430, 440 shell comprises a first face and a second face opposite the first face. The first and second faces are opposite along the DB flange direction.

[0112] The second face 412 of the first end shell 410 is positioned opposite the first face 412 of the first intermediate shell. The second face 422 of the first intermediate shell 420 is positioned opposite the first face 431 of the second intermediate shell 430. The second face 432 of the second intermediate shell 430 is positioned opposite the first face 441 of the second end shell 440.

[0113] The intermediate shells 420, 430 are arranged between the end shells 410, 440. The intermediate shells 420, 430 include reception portions on their first face 421, 431 and on their second face 422, 432. The end shells 410, 440 include reception portions only on one of their faces 412, 441, specifically on their first face 411, 441 and their second face 412, 442. The end shells 410, 420 lack a reception portion on one of their faces 411, 442. The end shells 410, 440 include reception portions only on one of their first faces 411, 441 and on their second face 412, 442, namely on their face 412, 441 located opposite an intermediate shell 420, 430.

[0114] The conformer 400 further includes clamping means 460 configured to bring the shells 410, 420, 430, 440 together. As described previously, the clamping means 460 are present at the peripheral portion of the shells 410, 420, 430, 440.

[0115] Preferably, the bottoms of the receiving sections include transverse channels 410a, 420a, 430a, 440a for gas circulation. The channels Transverse channels 410a, 420a, 430a, 440a preferably extend along the DB flange direction. Transverse channels 210a are through channels. The transverse canals 410a, 420a, 430a, 440a extend from the first face 411, 421, 432, 441 to the second face 412, 422, 432, 442 of the shells 410, 420, 430, 440. The transverse canals 410a, 440a of the end shells 410, 440 open onto one of the receiving portions of said end shell 410, 440. In particular, each transverse canal 410a, 440a opens onto one of the receiving portions of the end shells 410, 440. The transverse canals 420a, 430a of the intermediate shells 420, 430 connect the receiving portions of the first face 421, 431 of said intermediate shells 420, 430 to the receiving portions of the second face 422, 432 of said intermediate shells 420, 430.In particular, each transverse channel 420a, 430a connects a receiving portion of the first face 421, 431 of an intermediate shell 420, 430 to a receiving portion of the second face 422, 432 of said intermediate shell 420, 430.

[0116] The 450 conformation blocks preferably include gas circulation channels opening onto the fibrous preform 4. The gas circulation channels of the conformation blocks may be in the form of a channel network. The gas circulation channels of the 450 conformation blocks may be connected to the transverse channels 410a, 420a, 430a, 440a of the shells 410, 420, 430, 440. Each gas circulation channel may be connected to at least one transverse channel of the bottom of the receiving portion.

[0117] In the example illustrated in Figures 6 and 7, the receiving portions include a base. If the receiving portions do not include a base, it is possible that the shaping blocks arranged in contact with a receiving portion of the first face 421, 431 of an intermediate shell 420, 430 are also in contact with the receiving portion of the second face 422, 432 of said intermediate shell 420, 430. Thus, some shaping blocks are simultaneously in contact with two fibrous preforms 4. This configuration (not shown) makes it possible to limit the number of shaping blocks required and thus facilitate the placement and assembly of the loading 4004. In this configuration, the transverse channels can pass through the shaping blocks to connect the portions of reception of the first face 421, 431 of said intermediate shells 420, 430 to the reception portions of the second face 422, 432 of said intermediate shells 420, 430.

[0118] Of course, we do not depart from the scope of the invention if we combine the embodiment described in relation to Figure 5 with the embodiment described in relation to Figures 6 and 7. Thus, certain shells in Figures 6 and 7 could be broken down into several distinct shells.

[0119] Figure 8 illustrates a loading 5004 according to a variant of Figures 6 and 7. In this variant, the loading 5004 comprises a plurality of fibrous preforms 4 accommodated in a conformer 500. The conformer 500 comprises conformation blocks 550 and several shells 510, 520, 530, 540 stacked and held by clamping means 560 as described in connection with Figures 6 and 7. As in the example of Figures 6 and 7, the shells 510, 520, 530, 540 each comprise a plurality of transverse channels 510a, 520a, 530a, 540a.

[0120] Loading 5004 defines a clamping direction DB, also called the stacking direction, as described previously, and a principal gas flow direction DP perpendicular to the clamping direction DB. The principal gas flow direction DP corresponds to the main direction of gases that will pass through loading 5004 when it is placed in a gaseous infiltration facility. Thus, the principal gas flow direction DP extends from the gas inlet to the gas outlet of the gaseous infiltration facility in which loading 5004 will be placed.

[0121] In this variant, the intermediate shells 520, 530 further comprise longitudinal channels 520f, 530f. The longitudinal channels 520f, 530f extend transversely to the flange direction DB. The longitudinal channels extend along the principal direction of gas flow. The longitudinal channels 520f, 530f of the intermediate shells 520, 530 are connected to the transverse channels 520a, 530a of said intermediate shells 520, 530. Preferably, each longitudinal channel 520f, 530f of the intermediate shells 520, 530 is connected to several transverse channels 520a, 530a. Each longitudinal channel 520f, 530f connects the transverse channels 520a, 530a of several receiving portions. In particular, Each longitudinal channel 520f, 530f connects the transverse channels 520a, 530a of a column or row of host portions. Each intermediate shell 520, 530 may include several longitudinal channels 520f, 530f. Preferably, each intermediate shell 520, 530 includes one longitudinal channel 520f, 530f for each column of host portions. The longitudinal channels 520f, 530f may extend parallel to each other.

[0122] The longitudinal channels 520f, 530f extend at a non-zero distance from the first and second faces of the shells 520, 530. The longitudinal channels 520f, 530f do not open onto the first and second faces of the shells 520, 530. Preferably, the longitudinal channels 520f, 530f of one of the intermediate shells 520, 530 open outside said shell 520, 530 between the first and second faces of said shell 520, 530. One end of the longitudinal channels 520f, 530f is intended to be on the side of the gas inlet of a gas infiltration system. The longitudinal channels 520f, 530f are preferably through channels.Thus, gases can enter the conformer 500 through any spacing between the shells along the flange direction DB, through the transverse channels 510a, 520a, 530a, 540a of the end shells 510, 540 but also through the longitudinal channels 520f, 530f of the intermediate shells 520, 530. Such longitudinal channels 520f, 530f thus make it possible to improve the transport of gases towards the fibrous preforms located between the intermediate shells 520, 530.

[0123] Figure 9 illustrates a loading 6004 according to a variant of Figures 6 and 7. In this variant, the loading 6004 comprises a plurality of fibrous preforms accommodated in a conformer 600. The conformer 600 comprises conforming blocks and several shells 620, 630, 640 stacked and held by clamping means 660 as described in connection with Figures 6 and 7. As in the example of Figures 6 and 7, the shells 620, 630, 640 each comprise a plurality of transverse channels 621a, 622a.

[0124] Loading 6004 defines a bridle direction DB, also called the stacking direction, as described previously, and a principal gas flow direction DP perpendicular to the bridle direction DB. main gas flow DP corresponds to the direction extending from the gas inlet to the gas outlet of the installation for chemical infiltration in gaseous phase in which the 6004 load will be placed.

[0125] The loading 6004 extends between a main gas inlet surface 601 and a main gas outlet surface 602 along the main gas flow direction DP. The main gas inlet surface 601 is intended to be on the gas inlet side of a gaseous infiltration installation, and the main gas outlet surface 602 is intended to be on the gas outlet side of a gaseous infiltration installation.

[0126] In this variant, the intermediate shells 620, 630 comprise a plurality of internal chambers 621, 622. The internal chambers are arranged in columns and rows. Preferably, the number of rows and columns of internal chambers in each intermediate shell corresponds respectively to the number of rows and columns of the receiving portions. Thus, in the example illustrated in Figure 9, each shell of the 6004 load comprises four first internal chambers 621 and four second internal chambers 622.

[0127] The internal chambers 621 and 622 extend transversely to the flange direction DB. In each column of internal chambers, the first internal chamber 621 and the second internal chamber 622 are adjacent along the principal gas flow direction. The internal chambers 621 and 622 are located at a non-zero distance from the first and second faces of the shells 620 and 630.

[0128] A first plurality of transverse canals 621a opens into the first internal chamber 621, and a second plurality of transverse canals 622a opens into the second internal chamber 622. Preferably, the first plurality of transverse canals 621a connects the first internal chamber 621 to a receiving portion located on the first face of the intermediate shell 620, 630 and to a receiving portion located on the second face of said intermediate shell 620, 630. Similarly, the second plurality of transverse canals 622a preferably connects the second internal chamber 622 to another receiving portion located on the first face of the intermediate shell 620, 630 and to another receiving portion located on the second face of said intermediate shell 620, 630. The Reception areas connected to the first internal room 621 are different from reception areas connected to the second internal room 622.

[0129] The first internal chambers 621 include at least one first gas inlet port 621e, and the second internal chambers 622 include at least one second gas inlet port 622e. The gas inlet ports 621e and 622e are located on the main gas inlet surface 601. The gas inlet ports 621e and 622e open onto the main gas inlet surface 601. The length of the gas inlet ports 622e of the second internal chamber(s) 622 along the main gas flow direction DP is greater than the length of the first internal chamber(s) 621 along the main gas flow direction DP. Preferably, each first gas inlet port 621e is flanked by two second gas inlet ports 622e opening into the same second internal chamber 622. Thus, the second internal chambers 622 can be supplied with gas independently of the first internal chambers 621.

[0130] The first internal chamber 621 can be connected to the second internal chamber 622 of the same column by one or more leakage channels. Such leakage channels generate a pressure drop that forces the gases through the preforms. This results in a gas flow mode known as "semi-forced flow". Similarly, the second internal chamber 622 can include one or more gas outlet ports opening onto the main gas outlet surface 602.

[0131] Thus, gases can enter the conformer 600 through any spacing between the shells along the flange direction DB, through the transverse channels of the end shells 640 but also through the gas inlet ports 621e, 622e of the internal chambers of the intermediate shells 620, 630. As the second internal chambers 622 are supplied with gas independently of the first internal chambers 621, even the reception portions far from the main gas inlet surface 601 are properly supplied with gas.

[0132] In all the loading examples presented previously, the former is made of a material configured to withstand high The former is designed to withstand temperatures, for example, between 900°C and 1500°C. The former is made of a material configured to withstand low pressures, for example, between 50 mbar and 150 mbar. Thus, the former can typically be made of graphite or another refractory material. The shells and forming blocks can be made of the same material. The shells can be made of a different material than the forming blocks.

[0133] The fiber preforms 4 or 5 used are intended to form the fibrous reinforcement of a composite material part. In particular, the fiber preforms 4 or 5 can be blade fiber preforms, for example, blades comprising platforms and swashplates. The number and shape of the forming blocks must be adapted to the shape of the fiber preform.

[0134] The present invention also relates to a method of preparing a load as described above, illustrated in Figure 10.

[0135] According to a first step 1000, a fibrous texture 1 is produced. Preferably, the fibrous texture is obtained by weaving. The fibrous texture 1 can be obtained in a well-known manner by weaving on a Jacquard loom. The fibrous texture 1 is preferably woven in a single piece to improve its mechanical properties. The fibrous texture 1 can be produced in a single piece by three-dimensional weaving. By "three-dimensional weaving," we mean a weaving method in which at least some of the warp yarns bind weft yarns over several weft layers. A reversal of the roles between warp and weft is possible. It is considered that a fibrous texture produced by three-dimensional weaving may include another type of weave on its surface, for example, two-dimensional weaving, to improve its surface finish.The fibrous texture 1 can, for example, exhibit a three-dimensional weave structure of the interlock or multisatin type. Various three-dimensional weaving methods that can be used to form the fibrous texture 1 are described in document WO 2006 / 136755. The fibrous texture 1 may include one or more unlinkings. The fibrous texture 1 can exhibit a wide variety of shapes.

[0136] According to a second step 2000, the fibrous texture 1 is cut to obtain a fibrous rough 2. The cutting can be carried out in a well-known way by water jet cutting or by laser cutting.

[0137] According to a third step 3000, the fibrous blank 2 is shaped in a shaping mold to obtain a flexible fibrous preform 3. The shaping mold is distinct from a former. The shaping mold has a simple design. The shaping mold is typically made of metal. Generally, the shaping mold is made of a material less resistant to high temperatures and chemical interactions than the material used for the former.

[0138] According to a fourth step 4000, the flexible fibrous preform 3 is stiffened to obtain a stiffened fibrous preform 4 such as those described previously. The stiffening of the fibrous preform 3 is carried out while it is held in the forming mold. The stiffening of the flexible fibrous preform 3 can be carried out using several methods.

[0139] According to a first method, the flexible fibrous preform 3 can be stiffened using a fugitive resin. The fugitive resin can, for example, comprise polyvinyl alcohol (PVA) and / or poly(2-ethyl-2-oxazoline). For this purpose, the flexible fibrous preform 3 is first impregnated with a resin, and then the resin is cured while the flexible fibrous preform 3 is shaped in the shaping mold. The pre-impregnation with the resin can be carried out between the first step 1000 and the second step 2000, on the uncut fibrous texture 1. The pre-impregnation with the resin can also be carried out between the second step 2000 and the third step 3000, on the unshaped fibrous blank 2. Finally, the pre-impregnation with the resin can be carried out between the third step 3000 and the fourth step 4000, on the flexible fibrous preform 3 shaped in the shaping mold.The resin is hardened inside the flexible fibrous preform 3 during the fourth step 4000 so as to obtain the rigidified fibrous preform 4.

[0140] According to a second method, the flexible fibrous preform 3 can be stiffened by freezing. For this purpose, the flexible fibrous preform 3 is The flexible fibrous preform 3 is first impregnated with a liquid, for example, water, and then frozen while being shaped in the forming mold. It has been established that the technical assumption that freezing the fibrous preform with water would not provide sufficient rigidity was unfounded. Pre-impregnation with water can be carried out between the first step (1000) and the second step (2000) on the uncut fibrous texture 1. Pre-impregnation with water can also be carried out between the second step (2000) and the third step (3000) on the unshaped fibrous blank 2. Finally, pre-impregnation with water can be carried out between the third step (3000) and the fourth step (4000) on the flexible fibrous preform 3 after it has been shaped in the forming mold.The flexible fibrous preform 3 is frozen during the fourth step 4000 so as to obtain the rigidified fibrous preform 4.

[0141] Other liquids can be used in this second method. However, it is preferable that the liquid remain liquid at room temperature and solidify at moderately low temperatures to facilitate its use. The liquid must also not contaminate or degrade the fiber preform. Water offers several advantages in this second method: it is inexpensive and readily available, with low risks of contamination or degradation of the fibers in the fiber preform, and it also limits fiber dispersion during shaping. Furthermore, it is liquid at room temperature and freezes at a temperature easily attainable.

[0142] Other methods than those described above can of course be used to obtain a temporarily rigid fibrous preform.

[0143] After the fourth step 4000, the stiffened fibrous preform 4 is removed from the forming mold. Because the fibrous preform 4 is rigid, it is self-supporting. Thus, the stiffened fibrous preform 4 retains its shape even outside the forming mold.

[0144] According to a fifth step 5000, the stiffened fibrous preform 4 is placed in a conformer such as those described previously. The conformer is different from the shaping mold used in step 3000. The use of a simplified former with forming blocks lacking fastening means, according to the invention, is facilitated by the self-supporting nature of the stiffened fibrous preform 4. Since the stiffened fibrous preform 4 is self-supporting, the forming blocks can be easily arranged around and in contact with the stiffened fibrous preform 4. When the shells and forming blocks are arranged around the stiffened fibrous preform 4, the clamping means are activated to bring the shells together. The stiffened fibrous preform 4 is thus locked in the former, the forming blocks being held against the stiffened fibrous preform 4 by the shells. This results in a stiffened fibrous preform 4 held within the former.Therefore, a loading is obtained in accordance with the invention, such as those described above.

[0145] According to a sixth step 6000, the stiffened fibrous preform 4 held in the former is de-stiffened. This yields a de-stiffened fibrous preform 5 held in the former. Consequently, a loading according to the invention is obtained.

[0146] The de-rigidification of the rigidified fibrous preform 4 can be carried out in several ways depending on the method used for the rigidification.

[0147] If the fibrous preform has been stiffened using the first method described above, the resin can be removed, for example, by heat treatment, ultrasonic treatment, or the application of a solution, or by a combination of these methods. The chosen removal method must be suitable for the type of resin used. The chosen removal method can also be adapted to the accessibility of the fibrous preform 4 in the conformer. In the case of removal by heat treatment, the resin can be exposed to a temperature suitable for the resin, for example, 450°C. In this case, the temperature increase can be achieved by heating the mold. In the case of removal by ultrasound, an ultrasonic bath can be used. In the case of removal by the application of a solution, the chosen solution must be suitable for the resin, and a suitable temperature must be selected. In particular, if the resin used is Polyvinyl alcohol (PVA) can be removed with water at a temperature above 90°C. Removal by application of a solution can be carried out using an ultrasonic bath.

[0148] If the fibrous preform has been stiffened using the second method described previously, it is simply thawed to remove the water or fluid used. Then, in step 6000, the fibrous preform is heated. As the fibrous preform heats up, it expands. Consequently, the fibrous preform expands inside the former. The de-stiffened fibrous preform contributes to the pressure that clamps the formers between the former and the formers. This ensures that the fibrous preform is properly locked inside the former. The second stiffening method is therefore particularly advantageous.

[0149] The de-rigidified fibrous preform 5 present in the conformer can then be consolidated by chemical infiltration in the gas phase known as "CVI".

[0150] As is well known, the charge according to the invention can be placed in a gaseous infiltration system, for example, a gaseous chemical infiltration system. The gaseous chemical infiltration system may include an enclosure defining a reaction chamber equipped with a gas inlet pipe that may open into a homogenization zone for homogenizing the gas(s) before their diffusion into the reaction chamber. The reaction chamber may include a support on which the charge is intended to be deposited. Residual gases can be extracted at the top of the system via a discharge pipe connected to suction means. Heating is provided, for example, by a susceptor.

[0151] To achieve chemical infiltration in the gas phase, one or more reactive gases are introduced into the reaction chamber. The consolidation of the preform 5 is ensured, in a manner well known per se, by the deposition within it of the material produced by the decomposition of the precursor(s) contained in the reactive gas(s) diffusing into the accessible internal pores of the preform 5. The reactive gas(s) may contain one or more precursors of an interphase material or one or more precursors of a ceramic matrix. The material The interphase or ceramic matrix precursor is intended to coat the strands of the fibrous preform 5. For example, as an interphase precursor, the reactive gas(s) may contain one or more boron nitride (BN) precursors. For example, as a ceramic matrix precursor, the reactive gas(s) may contain one or more silicon carbide (SiC) precursors. Methyltrichlorosilane (MTS) can be used as a silicon carbide (SiC) precursor in a manner that is well known.

[0152] Chemical infiltration in the gas phase allows the consolidation of the fibrous preform 5. Chemical infiltration in the gas phase thus makes it possible to obtain a consolidated fibrous preform, which is self-supporting.

[0153] The fibrous preform 5 can be subjected to several gas-phase chemical infiltrations, for example to a first gas-phase chemical infiltration to deposit an interphase and then to a second gas-phase chemical infiltration to deposit ceramic matrix material.

[0154] Consolidation can allow the formation of a satisfactory matrix within the pores of the fibrous preform, resulting in a final part made of composite material. However, generally, after consolidation of the fibrous preform, it is densified using a matrix.

[0155] Once the fibrous preform is consolidated, it can be densified using a matrix to obtain the final composite part. Since the consolidated fibrous preform is self-supporting, densification is preferably performed outside the former.

[0156] For example, a powder infiltration step can be carried out using a well-known method. Powder infiltration can be achieved using a slurry, for example, according to the so-called "STM" (Slurry Transfer Molding) process. This step allows for the rapid formation of a portion of the matrix within the pores of the fibrous preform.

[0157] An additional liquid infiltration step, called "MI" for "Melt Infiltration", can also be carried out. This additional liquid infiltration step is preferably carried out after the infiltration step of powder. This additional step is classically carried out by introducing a composition including molten silicon into the remaining porosities of the fibrous preform to obtain the final matrix.

[0158] This results in a composite part whose fibrous reinforcement is formed by the fibrous preform. The resulting composite part preferably has a ceramic matrix. In particular, the resulting composite part is preferably of the SiC / SiC type.

[0159] The resulting composite material part can be a turbomachine part, for example a turbomachine blade or an aircraft casing.

Claims

Demands

1. A conformator (100) for gaseous infiltration intended to receive at least one fibrous preform (4), the conformator (100) comprising a plurality of conformation blocks (150), each comprising at least one conformation surface (150a) configured to be in contact with the fibrous preform(s) (4), the conformation surface (150a) having a shape complementary to the shape of one of the portions of the fibrous preform(s) (4), the conformator (100) being characterized in that it further comprises at least two shells (110, 120) arranged opposite each other, each comprising at least one receiving portion (110b, 120b) of the conformation blocks (150), the conformation blocks (150) further comprising at least one blocking surface (150b) configured to be in contact with one of the receiving portions (110b, 120b) shells (110, 120),the conformer (100) further comprising clamping means (160) configured to bring the shells (110, 120) closer together, so that when the conformer (100) accommodates one or more fibrous preforms (4), the conforming surfaces (150a) of the conforming blocks (150) form one or more cavities having the shape of the fibrous preform(s) (4) and accommodating the fibrous preform(s) (4), and the conforming blocks (150) are held against the fibrous preform(s) (4) by the shells (110, 120).

2. Shaper (100) according to claim 1, wherein the clamping means (160) are positioned on a peripheral portion (110c, 120c) of the shells (110, 120) located around the receiving portion(s) (110b, 120b).

3. Shaper (200; 400) according to claim 1 or 2, wherein the receiving portions (220b) of at least a portion of the shells (210, 220; 410, 440) comprise transverse channels (210a; 410a, 440a) for the circulation of gas opening onto the outside of the former (2004; 4004).

4. Shaper (400) according to any one of claims 1 to 3, the conformer (400) being formed by stacking in the order along a stacking direction of at least one first end shell (410), one or more intermediate shells (420, 430), and a second end shell (440), wherein the intermediate shell(s) (420, 430) comprise a first face (421, 431) arranged opposite an end shell (410) or another intermediate shell (420) and a second face (422, 432) opposite the first face (421, 431) arranged opposite an end shell (440) or another intermediate shell (430), the first face and the second face (421, 422, 431, 432) of the intermediate shell(s) (420, 430) comprising one or more conformation block (450) reception portions.

5. Shaper (400) according to claim 4, wherein transverse channels (420a, 430a) for gas circulation connect the receiving portions of the first face (421, 432) to the receiving portions of the second face (422, 432) of the intermediate shell(s) (420, 430).

6. Shaper (500) according to claim 5, wherein longitudinal channels (520f, 530f) for gas circulation extend inside the intermediate shell(s) (520, 530) at a non-zero distance from the first and second faces of the intermediate shell(s) (520, 530), the longitudinal channels (520f, 530f) being connected to the transverse channels (520a, 530a).

7. Shaper (600) according to claim 5 or 6, the conformer (600) extending between a principal gas inlet surface (601) and a principal gas outlet surface (602) along a principal gas flow direction (DP) perpendicular to the stacking direction (DB), wherein the intermediate shell(s) (620, 630) comprise a plurality of internal chambers (621, 622) extending at a non-zero distance from the first and second faces of the intermediate shell(s) (620, 630), the internal chambers (621, 622) of each intermediate shell (620, 630) being arranged in a column extending along the principal gas flow direction (DP), a plurality of transverse channels (621a, 622a) opening into each internal chamber (621, 622), each internal chamber (621, 622) comprising at least one gas inlet port (621e, 622e) disposed on the main gas inlet surface (601).

8. Loading (1004) for gaseous infiltration comprising a conformer (100) according to any one of claims 1 to 7 and one or more fibrous preforms (4), the conformer (100) receiving the fibrous preform(s) (4) so ​​that the conformation blocks (150) are blocked against the fibrous preform(s) (4) by the shells (110, 120).

9. Loading (1004) according to claim 8, wherein the fibrous preform(s) (4) are stiffened.

10. A method for preparing a load intended to be placed in a gaseous infiltration installation, said load comprising one or more fibrous preforms (5) arranged in a conformer (100), the method comprising: - (3000) the shaping of one or more fibrous blanks (2) into one or more fibrous preforms (3) in a shaping mold, - (4000) the stiffening of the fibrous preform(s) (3) in the forming mold, - the removal of the stiffened fibrous preform(s) (4) from the shaping mold, - (5000) the placement of the stiffened fibrous preform(s) (4) in a former (100) so as to obtain a loading (1004) according to claim 8 or 9, - (6000) the de-rigidification of the fibrous preform(s) (4) arranged in the conformer.

11. A gaseous infiltration process comprising: - the preparation of a load in accordance with the process according to claim 10, - the arrangement of the load in a gaseous infiltration installation, then - the infiltration by gaseous means of the fibrous preform(s) (5) of the loading.

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