Simplified block former for gaseous infiltration

Abstract

Simplified block former for gaseous infiltration. The invention relates to a load (1004) for gaseous infiltration comprising one or more fibrous preforms (4) and a former (100), the former comprising a plurality of conforming blocks (150) arranged in contact with one of the fibrous preforms (4), the load (1004) 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) for the conforming blocks (150), the conforming 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 together by clamping means. (160) so that the conformation blocks (150) are held against the fibrous preform(s) (4) by the shells (110, 120). Figure for the abstract: Fig. 1

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 parts with excellent thermomechanical properties, composite materials are commonly used. The use of composite materials helps optimize turbomachine performance, particularly 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, which impacts the turbomachine's 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 fibrous blank. This fibrous blank is then shaped in a former to produce a fibrous preform, said fibrous preform being intended to form the fibrous reinforcement of the composite part to be obtained. 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 former and then densified by a matrix in one or more stages.

[0004] The former used in such a process often has a complex architecture. Indeed, the former typically comprises a frame onto which a plurality of blocks are mounted and bolted so as to define a cavity having the shape of the fibrous preform to be obtained. The blocks are assembled one by one around the blank. The fibrous material is gradually shaped until the fibrous preform is obtained. Such a former, with its blocks and block-fixing systems, is very bulky. Furthermore, positioning the former around the fibrous blank requires numerous and time-consuming manual operations. Description of the invention

[0005] In order to remedy the aforementioned drawbacks, the invention proposes a simplified and easy-to-assemble former.

[0006] To this end, the invention proposes a charge for gaseous infiltration 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 charge being characterized in that it further comprises at least two shells disposed opposite each other each comprising at least one portion for receiving the conforming blocks, the conforming blocks further comprising at least one blocking surface disposed in contact with one of the portions for receiving the shells,The shells are brought together by means of clamping so that the conformation blocks are held against the fibrous preform(s) by the shells.

[0007] Thus, using shells to hold the conforming blocks in place allows the use of conforming blocks without fastening means. This makes the conformer lighter and less bulky, as well as easier and faster to set up. Furthermore, since the system for holding the fibrous preform is simplified, gas access to the fibrous preform is improved.

[0008] 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 receives one or several fibrous preforms, the conformation surfaces of the conformation blocks form one or more cavities having the shape of the fibrous preform(s) and accommodating the fibrous preform(s), and the conformation blocks are blocked against the fibrous preform(s) by the shells.

[0009] According to a particular embodiment of the invention, the fibrous preform(s) are stiffened.

[0010] Placing the conformer around the fibrous preform is very difficult to achieve with a conventional fibrous preform, which is too flexible and deforms easily. Therefore, it is strongly recommended to stiffen the fibrous preform before proceeding with the conformer placement to obtain the loading according to the invention. Once the properly stiffened fibrous preform is placed in the conformer, it can be unstiffened. The loading, including the unstiffened fibrous preform, is also included in the present invention.

[0011] The fibrous preform(s) may be stiffened by a hardened fugitive resin. The fibrous preform(s) may be stiffened by impregnation with a fluid and by freezing said fluid, said fluid being, for example, water.

[0012] 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.

[0013] Thus, the clamping means do not impede the flow of gases. The clamping means are also simpler to implement, since the shaping blocks do not hinder their installation.

[0014] According to another particular embodiment of the invention, the receiving portions of at least a part of the shells include transverse channels for the circulation of gas opening onto the outside of the conformer.

[0015] Thus, gases can penetrate the feed by means of these transverse channels to improve the amount of gas delivered to the fibrous preform(s). This feature applies to the end shells of the conformer when the conformer includes intermediate shells located between the end shells.

[0016] According to another particular embodiment of the invention, the loading, or the former, 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 shell intermediate, the first face and the second face of the intermediate shell(s) comprising one or more portions for receiving the conformation blocks.

[0017] Thus, the loading according to the invention can accommodate a larger number of fibrous preforms while maintaining relatively compact dimensions.

[0018] 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).

[0019] Such transverse channels make it possible to improve the circulation of gases inside the load, and in particular to improve the exposure to gases of the fibrous preforms located in the center of the load.

[0020] 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.

[0021] Such longitudinal channels make it possible to improve the circulation of gases inside the load, and in particular to improve the exposure to gases of the fibrous preforms located in the center of the load and in the parts of the load furthest from the arrival of the gases.

[0022] The longitudinal channels may be through channels and open outside the load. In this case, the longitudinal channels provide an additional entry point for the gases so that they can penetrate the load more easily.

[0023] 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, in which 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.

[0024] 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.

[0025] 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:

[0026] - the shaping of one or more fibrous blanks into one or more fibrous preforms in a shaping mold,

[0027] - the stiffening of the fibrous preform(s) in the forming mold,

[0028] - the removal of the rigidified fibrous preform(s) from the shaping mold,

[0029] - the placement of the stiffened fibrous preform(s) in a conformer of in order to obtain a load as described previously,

[0030] - the de-rigidification of the fibrous preform(s) arranged in the conformer.

[0031] The invention further relates to a gaseous infiltration method comprising:

[0032] - the preparation of a load in accordance with the process as described previously,

[0033] - the arrangement of the load in an installation for infiltration by way gaseous, then

[0034] - gaseous infiltration of the fibrous preform(s) of the loading.

[0035] In particular, it may involve chemical infiltration in the gas phase. Brief description of the drawings

[0036] [Fig.1] Fig.1 is an exploded perspective view of a load according to the invention.

[0037] [Fig.2] The [Fig.2] is a perspective view of the closed loading of the [Fig.1].

[0038] [Fig.3] Fig.3 is an exploded perspective view of another load according to the invention comprising a plurality of fibrous preforms.

[0039] [Fig.4] The [Fig.4] is a perspective view of the closed loading of the [Fig.3].

[0040] [Fig. 5] Fig. 5 is an exploded perspective view of another load according to a variant of the loading of figures 3 and 4.

[0041] [Fig.6] The [Fig.6] is an exploded perspective view of another load according to the invention comprising more than two shells.

[0042] [Fig.7] The [Fig.7] is a cross-sectional view of the loading of the [Fig.6].

[0043] [Fig.8] Fig.8 is a cross-sectional view of another loading according to a variant of the Loading figures 6 and 7.

[0044] [Fig.9] The [Fig.9] is a cross-sectional view of another loading according to another variant of the loading of figures 6 and 7.

[0045] [Fig. 10] The [Fig. 10] is a flowchart illustrating a method of preparing a load according to the invention. Description of the implementation methods

[0046] Figures 1 and 2 illustrate an example of loading 1004 according to the invention.

[0047] 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.

[0048] The conformer 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 bridle direction Db.

[0049] The rigidified fibrous preform 4 is disposed between the first shell 110 and the second shell 120.

[0050] 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 flange direction DB. The conformation blocks 150 are without fastening means.

[0051] The first shell 110 comprises a receiving portion 110b. The receiving portion 110b is configured to be in contact with the conformation blocks 150. The receiving portion 110b may also be in contact with the fibrous preform 4. Conversely, the first shell 110 may be held 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 comprises a peripheral portion 110c surrounding the receiving portion 110b.

[0052] 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 may also be in contact with the fibrous preform 4. Conversely, the second shell 120 may be held 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.

[0053] The conformation blocks 150 comprise at least one conformation face 150a configured to be in contact with the fibrous preform 4. The conformation faces 150a of the conformation blocks 150 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.

[0054] 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.

[0055] The receiving portions 110b, 120b preferably include lateral edges HObb, 120bb 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.

[0056] Preferably, at least a portion 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 a portion 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 a portion 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.

[0057] The receiving portions 110b, 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, 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.

[0058] The receiving portions 110b, 120b may also be bottomless. In this case, the lateral edges define a through opening along the clamping direction DB. The receiving portions 110b, 120b may then be formed by the lateral edges. If there is no bottom, it is highly preferable that at least part of the lateral edges be inclined relative to the clamping direction DB, in order to facilitate the locking of the forming blocks.

[0059] The first and second shells may include a base. The first and second shells may be without a base. According to one embodiment, only one of the shells may include a base. In the example illustrated in Figures 1 and 2, the second shell 120 includes a base and the first shell 110 is without a base.

[0060] The presence of a base improves the locking of the conformation blocks 150 in the load. However, the presence of a base limits the circulation of gases when the load is arranged in a gaseous infiltration system. Thus, the configuration in which only one of the shells has a base is an interesting compromise.

[0061] The bottom may include transverse channels for gas circulation. The transverse channels preferably extend along the DB flange direction. The transverse channels are through channels. The transverse channels open onto the receiving portion.

[0062] 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.

[0063] Thus, gas circulation in the conformer 100 can be ensured in several ways, alone or in combination. The 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 conforming blocks.

[0064] 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 make it possible to bring the first shell 110 and the second shell 120 closer together along the clamping direction DB.

[0065] 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 shaping 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 clamped with a reduced number of clamping means 160.

[0066] The clamping means 160 may, for example, be formed by a plurality of orifices present on the peripheral portions 110c, 120c of the shells 110, 120 extending along the clamping direction DB and by bolts passing through said orifices. The clamping means 160 may, for example, be formed by a plurality of orifices present on the peripheral portions 110c, 120c of the shells 110, 120 extending along the clamping direction DB and by studs passing through said orifices.

[0067] 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.

[0068] The loading in Figures 1 and 2 comprises a single fibrous preform. In order to increase the number of fibrous preforms that can be treated by gas infiltration, the invention also proposes loadings with a conformer accommodating a plurality of fibrous preforms, as in the examples illustrated in Figures 3 to 9.

[0069] Figures 3 and 4 illustrate an example of loading 2004 comprising a conformer 200 receiving 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.

[0070] The conformer 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 bridle direction Db.

[0071] The stiffened fibrous preforms 4 are arranged between the first shell 210 and the second shell 220.

[0072] 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 flange direction DB. The conformation blocks 250 are without fastening means.

[0073] 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.

[0074] 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 flange direction DB. The receiving portions are present on the first face 211.

[0075] The second shell 220 comprises a plurality of receiving portions 220b configured to each 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. Conversely, the second shell 220 may be maintained at a non-zero distance from the fibrous preforms 4 by the conformation blocks 250. The second shell 220 is then 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.

[0076] 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.

[0077] The conformation blocks 250 comprise 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.

[0078] 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.

[0079] 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.

[0080] Preferably, at least a portion 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 a portion of the lateral edges of the receiving portions 220b relative to the clamping direction DB 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 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.

[0081] The receiving portions 220b may include a base. The base extends transversely to the clamping direction DB. Preferably, the base extends perpendicularly to the clamping direction DB. If the receiving portions 220b 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 250b of the conformation blocks 250.

[0082] Preferably, the bottom comprises transverse channels 210a for gas circulation. The transverse channels 210a preferably extend along the flange 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.

[0083] The conformation blocks 250 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 250 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.

[0084] The receiving portions 220b may also be bottomless. In this case, the lateral edges define a through opening along the bridle direction Db. The through opening leads to the first face 211, 221 and the second face 212, 222 of the shell 210, 220. The receiving portions 220b may then be formed by the lateral edges. If there is no bottom, it is highly preferable that at least part of the lateral edges be inclined relative to the bridle direction DB, in order to facilitate the locking of the conformation blocks.

[0085] The first and second shells may include a base. The first and second shells may be without a base. According to one embodiment, only one of the shells may include a base. In the example illustrated in Figures 3 and 4, shells 210 and 220 each include a base.

[0086] The presence of a base improves the blocking of the 250 conformation blocks in the load. However, the presence of a base limits gas circulation when the load is placed in a gaseous infiltration system. Thus, the configuration in which only one of the shells includes a base is a good compromise.

[0087] The conformer 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 allow the first shell 210 and the second shell 220 to be brought together according to the clamping direction DB.

[0088] 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 shaping 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 clamped with a reduced number of clamping means 160.

[0089] The clamping means 260 may, for example, be formed by a plurality of holes present on the peripheral portions 220c of the shells 210, 220 extending along the clamping direction DB and by bolts passing through said holes. The clamping means 260 may, for example, be formed by a plurality of holes present on the peripheral portions 220c of the shells 210, 220 extending along the clamping direction DB and by studs passing through said holes.

[0090] The receiving portions 220b can be arranged in rows and columns. In the example illustrated 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.

[0091] 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 entire columns of receiving portions 220. In particular, each crenellation or tooth carries a single entire 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 entire columns of 220b receiving portions. In . In particular, in the example illustrated in figures 3 and 4, each flat portion accommodates a single whole column of 220b receiving portions.

[0092] 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 may be stiffened fibrous preforms 4, as illustrated in Figure 5. However, it does not depart from the scope of the invention if the loading comprises de-stiffened fibrous preforms 5, as described later.

[0093] 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.

[0094] In the example illustrated in [Fig.5], the conformer 300 comprises four first shells 310. We do not, of course, go out of bounds if the conformer comprises two or three first shells or more than four first shells.

[0095] The stiffened fibrous preforms 4 are arranged between the first shells 310 and the second shell 220.

[0096] The plurality of conformation blocks 250 described in connection with 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 arranged between a first shell 311, 312, 313, 314 and the second shell 220.

[0097] The first shells 310 comprise a plurality of reception portions (not visible in [Fig.5]) configured to each accommodate a fibrous preform 4. Each first shell 311, 312, 313, 314 comprises at least one reception portion. The receiving portions are configured to be in contact with the conformation blocks 250. The receiving portions can also be in contact with the fibrous preforms 4. Conversely, the first shells 311, 312, 313, 314 can be maintained 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 furthermore each include a peripheral portion surrounding the receiving portions, and connecting the receiving portions to each other if the first shell includes more than one receiving portion.

[0098] 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 opposite along the flange direction DB. The receiving portion(s) of each first shell 311, 312, 313, 314 are present on the first face. The The first faces of the first shells 311, 312, 313, 314 are arranged opposite the second face 222 of the second shell 222.

[0099] The receiving portions of the first shells 311, 312, 313, 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 with respect to the clamping direction DB. Thus, the clamping of the conformation blocks 250 of the load 3004 is improved. The inclination with respect 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 with respect 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.

[0100] The receiving portions of the first shells 310 may include a bottom. The bottom extends transversely to the flange direction DB. Preferably, the bottom extends perpendicularly to the flange direction DB. 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 blocking faces 250b of the conformation blocks 250.

[0101] Preferably, the bottom of the receiving portions of the first shells 310 comprises transverse channels 310a for gas circulation. The transverse channels 310a preferably extend along the flange direction DB. The transverse channels 310a are through channels. The transverse channels 310a open onto one of the receiving portions of one of the first shells 310. In particular, each transverse channel 310a opens onto one of the receiving portions of one of the first shells 310. The transverse channels 310a extend from the first face to the second face of the first shell 310.

[0102] The receiving portions of the first shells 310 may also be bottomless. In this case, the lateral edges define a through opening along the flange direction DB. The through opening leads to the first and second faces of the first shells 310. The receiving portions can then be formed by the lateral edges. If there is no bottom, it is highly preferable that at least part of the lateral edges be inclined relative to the flange direction DB, in order to facilitate the locking of the forming blocks.

[0103] The conformer 300 further includes clamping means 360 configured to bring the first shells 310 closer to the second shell 220. In particular, The 360 ​​clamping means allow the first shells 310 and the second shell 220 to be brought together according to the clamping direction DB.

[0104] 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 conformation 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.

[0105] In this embodiment, 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 entire column of receiving portions or at least one entire row of receiving portions. In particular, each first shell 310 comprises a single entire column of receiving portions or a single entire row of receiving portions.

[0106] 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.

[0107] The loads in Figures 1 to 5 comprise only two superimposed shells along the clamping direction DB. 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 clamping direction Db accommodating a plurality of fibrous preforms, as in the examples illustrated in Figures 6 to 9.

[0108] Figures 6 and 7 illustrate an example of a load 4004 comprising at least three stacked shells along the clamping direction DB, also called 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, this does not depart from the scope of the invention if the load comprises only three stacked shells, or if it comprises five or more stacked shells along the clamping direction DB.

[0109] The loading 4004 comprises a conformer 400 receiving a plurality of stiffened fibrous preforms 4. The fibrous preforms may be preforms stiffened fibrous 4, as illustrated in figures 6 and 7. However, we do not depart from the scope of the invention if the loading includes de-stiffened fibrous preforms 5, as described later.

[0110] The conformer 400 comprises a stack of several shells arranged in the clamping direction DB. The conformer 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 clamping direction DB. Each shell comprises at least one receiving portion and one peripheral portion, the receiving portion(s) and the peripheral portion having the same characteristics as described above.

[0111] A plurality of conformation blocks 450 is arranged between the shells 410, 420, 430, 440. The conformation blocks 450 may have the same characteristics as the conformation blocks described previously.

[0112] Each shell 410, 420, 430, 440 comprises a first face and a second face opposite the first face. The first face and the second face are opposite along the flange direction DB.

[0113] The second face 412 of the first end shell 410 is arranged opposite the first face 412 of the first intermediate shell. The second face 422 of the first intermediate shell 420 is arranged opposite the first face 431 of the second intermediate shell 430. The second face 432 of the second intermediate shell 430 is arranged opposite the first face 441 of the second end shell 440.

[0114] 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 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 their second face 412, 442, namely on their face 412, 441 located opposite an intermediate shell 420, 430.

[0115] 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.

[0116] Preferably, the bottoms of the receiving portions include transverse channels 410a, 420a, 430a, 440a for gas circulation. The transverse channels 410a, 420a, 430a, 440a preferably extend along the DB flange direction. The 210a transverse channels 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.

[0117] The conformation blocks 450 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 450 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.

[0118] 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 illustrated) 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 cross the conformation blocks to 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.

[0119] We do not, of course, depart from the scope of the invention if we combine the embodiment described in relation to [Fig.5] with the embodiment described in relation to Figures 6 and 7. Thus, certain shells in Figures 6 and 7 could be decomposed into several distinct shells.

[0120] 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 together 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.

[0121] 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 the 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 6004 will be placed.

[0122] In this embodiment, 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 host 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 can comprise several longitudinal channels 520f, 530f.Preferably, each intermediate shell 520, 530 comprises a longitudinal channel 520f, 530f for each column of host portions. The longitudinal channels 520f, 530f may extend parallel to each other.

[0123] 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 Installation for gaseous infiltration. The longitudinal channels 520f, 530f are preferably through-channels. Thus, gases can enter the conformer 500 through any gap between the shells along the clamping 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 improve the delivery of gases to the fibrous preforms located between the intermediate shells 520, 530.

[0124] 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.

[0125] Loading 6004 defines a clamping direction DB, also called the stacking direction, as described previously, and a main gas flow direction DP perpendicular to the clamping direction DB. The main gas flow direction DP corresponds to the direction extending from the gas inlet to the gas outlet of the installation for the gas-phase chemical infiltration in which loading 6004 will be placed.

[0126] The charge 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.

[0127] 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 [Fig. 9], each shell of the load 6004 comprises four first internal chambers 621 and four second internal chambers 622.

[0128] The internal chambers 621, 622 extend transversely to the clamping direction Db. In each column of internal chambers, the first internal chamber 621 and the second internal chamber 622 are adjacent along the principal direction of gas circulation. The internal chambers 621, 622 are located at a non-zero distance from the first and second faces of the shells 620, 630.

[0129] A first plurality of transverse channels 621a opens into the first internal chamber 621, and a second plurality of transverse channels 622a opens into the second internal chamber 622. Preferably, the first plurality of transverse channels 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 channels 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 receiving portions connected to the first internal chamber 621 are different from the receiving portions connected to the second internal chamber 622.

[0130] The first internal chambers 621 comprise at least one first gas inlet port 621e and the second internal chambers 622 comprise at least one second gas inlet port 622e. The gas inlet ports 621e, 622e are located on the main gas inlet surface 601. The gas inlet ports 621e, 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.

[0131] 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 circulation 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.

[0132] Thus, gases can enter the conformer 600 through any gap 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. Since 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.

[0133] In all the loading examples presented above, the former is made of a material configured to withstand high temperatures, for example, temperatures between 900°C and 1500°C. The former is made of a material configured to withstand low pressures, for example, pressures between 50 mbar and 150 mbar. Thus, the former can conventionally be made of graphite or another refractory material. The shells and the forming blocks can be made of the same material. The shells can be made of a different material than the forming blocks.

[0134] The fibrous preforms 4 or 5 used are intended to form the fibrous reinforcement of a part made of composite material. In particular, the fibrous preforms 4 or 5 may be blade fibrous preforms, for example, blades comprising platforms and swashplates. The number and shape of the forming blocks must be adapted to the shape of the fibrous preform.

[0135] The present invention also relates to a method of preparing a load as described above, illustrated in [Fig. 10].

[0136] 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, in order 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, in order to improve its surface finish.The fibrous texture 1 can, for example, have 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 can include one or more unlinkings. The fibrous texture 1 can have a wide variety of shapes.

[0137] According to a second step 2000, the fibrous texture 1 is cut so as to obtain a fibrous rough 2. The cutting can be carried out in a well-known manner by water jet cutting or by laser cutting.

[0138] 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 conventionally 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.

[0139] 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 according to several methods.

[0140] According to a first method, the flexible fibrous preform 3 can be stiffened by means of 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 hardened 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.

[0141] According to a second method, the flexible fibrous preform 3 can be stiffened by freezing. For this purpose, the flexible fibrous preform 3 is first impregnated with a liquid, for example, water, and then the liquid-impregnated flexible fibrous preform 3 is frozen while the flexible fibrous preform 3 is being shaped in the shaping mold. It has been established that the technical assumption that freezing the fibrous preform with water would not provide sufficient stiffening was unfounded. The pre-impregnation with water can be carried out between the first step 1000 and the second step 2000, on the uncut fibrous texture 1. The 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. shaped in the shaping mold. The flexible fibrous preform 3 is frozen in the fourth step 4000 so as to obtain the rigidified fibrous preform 4.

[0142] Other liquids can be used in this second method. However, it is preferable that the liquid used remain liquid at room temperature and solidify at moderately low temperatures to facilitate its use in this second method. The liquid used must also not contaminate or degrade the fibrous 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 fibrous preform; it also limits fiber dispersion during shaping operations. Furthermore, it is liquid at room temperature and freezes at a temperature that is easily attainable.

[0143] Other methods than those described above can of course be used to obtain a temporarily rigid fibrous preform.

[0144] After the fourth step 4000, the stiffened fibrous preform 4 is removed from the forming mold. Since the fibrous preform 4 is rigid, it is self-supporting. Thus, the stiffened fibrous preform 4 retains its shape even outside the forming mold.

[0145] According to a fifth step 5000, the stiffened fibrous preform 4 is placed in a former such as those described above. The former is different from the forming mold used in the third 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 placed around and in contact with the stiffened fibrous preform 4. When the formers and forming blocks are placed around the stiffened fibrous preform 4, the clamping means are activated so as to bring the formers 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 formers.This results in a stiffened fibrous preform 4 held within the former. Consequently, a loading according to the invention is obtained, such as those described above.

[0146] According to a sixth step 6000, the stiffened fibrous preform 4 held in the former is de-rigidified. This yields a de-rigidified fibrous preform 5 held in the former. Consequently, a loading according to the invention is obtained.

[0147] The de-stiffening of the stiffened fibrous preform 4 can be carried out in several ways depending on the method used for stiffening.

[0148] If the fibrous preform has been stiffened according to the first method described above, the resin can, for example, be removed 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 said 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 said resin and a suitable temperature must be chosen.In particular, if the resin used is polyvinyl alcohol (PVA), it 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.

[0149] If the fibrous preform has been stiffened according to the second method described above, it is simply thawed to remove the water or fluid used. Thus, in the sixth 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 5 contributes to the pressure that clamps the formers between the former 5 and the formers. This ensures that the fibrous preform is properly locked inside the former. The second stiffening method is therefore particularly advantageous.

[0150] The de-rigidified fibrous preform 5 present in the conformer can then be consolidated by chemical infiltration in the gas phase known as "CVI".

[0151] 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 by means of a discharge pipe connected to suction means. Heating is, for example, provided by a susceptor.

[0152] In order to carry out 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 deposition within it of the produced material by decomposition of the precursor(s) contained in the reactive gas(s) diffusing within 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 interphase or ceramic matrix precursor material 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 precursors of boron nitride (BN). For example, as a ceramic matrix precursor, the reactive gas(s) may contain one or more precursors of silicon carbide (SiC). Methyltrichlorosilane (MTS) may be used as a precursor of silicon carbide (SiC) in a manner that is well known per se.

[0153] 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.

[0154] 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.

[0155] Consolidation can allow the formation of a satisfactory matrix within the pores of the fibrous preform, enabling the production of a final part made of composite material. However, generally, after consolidation of the fibrous preform, it is densified by means of a matrix.

[0156] Once the fibrous preform is consolidated, it can be densified by a matrix to obtain the final composite part. Since the consolidated fibrous preform is self-supporting, the densification is preferably carried out outside the former.

[0157] For example, a powder infiltration step can be carried out in a well-known manner. Powder infiltration can be carried out in a well-known manner using a slurry, for example according to the so-called "STM" process for "Slurry Transfer Molding". This step allows a portion of the matrix to be rapidly formed within the pores of the fibrous preform.

[0158] 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 powder infiltration step. This additional step is conventionally carried out by introducing a composition comprising molten silicon into the remaining pores of the fibrous preform to obtain the final matrix.

[0159] This yields a composite material part whose fibrous reinforcement is formed by the fibrous preform. The resulting composite material part is preferably ceramic matrix. In particular, the resulting composite material part is preferably of the SiC / SiC type.

[0160] The composite material part thus obtained 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 following a stacking direction of at least one first end shell (410), one or more intermediate shells (420, 430), and a second end shell (440), in which the or the intermediate shells (420, 430) include 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) including one or more portions for receiving the conformation blocks (450).

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) such that the blocks conformation (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 an installation for gaseous infiltration, said load comprising one or more fibrous preforms (5) arranged in a former (100), the method comprising: - (3000) shaping one or more fibrous blanks (2) into one or more fibrous preforms (3) in a shaping mold, - (4000) stiffening the fibrous preform(s) (3) in the shaping mold, - removing the stiffened fibrous preform(s) (4) from the shaping mold, - (5000) placing the stiffened fibrous preform(s) (4) in a former (100) so as to obtain a load (1004) according to claim 8 or 9, - (6000) de-stiffening the fibrous preform(s) (4) arranged in the former.

11. A gaseous infiltration process comprising: - preparing a load according to the process according to claim 10, - arranging the load in an installation for gaseous infiltration, then - gaseous infiltration of the fibrous preform(s) (5) of the load.

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