EP3464829B1 - Method for manufacturing a turbine engine casing with abradable coating - Google Patents

Description

The invention relates in particular to a method of manufacturing a support panel of abradable material for a turbomachine casing.

Aeronautical turbomachines are mainly constituted by at least one compressor, in which the air drawn into the air inlet of the turbomachine is compressed towards a combustion chamber in which the injected fuel is burned, then transmitted to at least one turbine in which the burnt gases are expanded to drive the compressor integral in rotation with the turbine, and finally discharged by an ejection device. Aircraft compressors and turbines consist of fins, or blades, which are rotated inside a casing which seals the air stream with the outside of the engine.

For example, the casing is made up of a succession of rings with which the blades provide an operating clearance. This play must be sufficient so that no friction comes to brake the rotation of the moving parts but it must be controlled to prevent a significant amount of gas from being diverted from the active surfaces of the blades. In order to ensure as high a return as possible, it is therefore important to master this game.

Indeed, it is known that the clearance existing between the ends of the movable blades and the casing forming the internal wall of the air flow stream degrades the efficiency of the engine of the turbomachine. In the case of a compressor housing in particular, this play can significantly modify and degrade the operation of the compressor until the appearance of a “pumping” phenomenon, which results from the stalling of the air flow from the surface. blades. Controlling the air circulation at the tip of the blades thus constitutes a primordial issue in order to obtain both good aerodynamic efficiency of the compressor or of the turbine and, in the particular case of a compressor, to have a sufficient margin against the pumping phenomenon.

In known manner, in order to control this play, the casing carries an annular coating of abradable material. This coating extends around and at a short radial distance from the blades, which can, in operation, rub against the abradable material and wear it out by friction. This makes it possible to optimize the radial clearances between the blades and the casing which surrounds them and therefore to limit the gas leaks at the vertically outer ends or ends of the blades.

The casing can be produced in the form of a monobloc ring, or a succession of sectors of rings, and the same goes for the abradable material which can be produced in the form of an annular cartridge or a succession of angular sectors of cartridges.

It is known to deposit the abradable material directly on a rigid element, as is the case in the document FR-2.922.950-A1 which teaches the deposition of an abradable material directly on an internal ferrule of a rectifier in rotating contact with a rotor.

However, the abradable material is preferably not fixed directly to the casing. Indeed, the housing receives a support panel consisting of a block of honeycomb material covered by a rigid skin, which provides support for the cartridge or cartridges of abradable material.

STATE OF THE PRIOR ART

According to the prior art of the document US-2014/150262-A1 , it is known to produce the casing from layers of a fibrous material which undergo an injection of resin which is then polymerized directly on a block of honeycomb material

According to the state of the prior art, when the material is intended to be added to an existing casing, it is known to produce the housing with abradable coating according to three main successive stages of manufacturing the support panel, machining of the support panel, and bonding of the support panel to the housing.

During a first step of manufacturing the support panel, a block of honeycomb material is covered with a skin preform of impregnated composite material, for example a preform made of carbon fibers impregnated with an epoxy resin. The preform has a wall and edges defining edges, and for this purpose, when the block of honeycomb material is covered by the preform, an intumescent material is interposed between the edges of the block and the edges of the preform. . Then, the assembly, shaped substantially in the form of a half-sandwich, is subjected to a simple baking during a second step so as to form a raw support panel.

The internal surface of the housing does not necessarily correspond to its theoretical profile. In particular, in the case of a casing made of composite material, it has been found that the internal face of the casing after manufacture does not necessarily have a perfectly circular section but could have an ovalization of its section. In addition, the internal face of the casing may have possible surface defects.

It is therefore necessary to carry out a machining of the external face of the support panel so that it best matches the internal face of the casing in order to minimize the deformations that the support panel could undergo, because these deformations would have the consequence of modify the position required for the cartridge of abradable material that the support panel must receive.

To do this, during a third step, the internal face of the casing is measured so as to deduce therefrom a three-dimensional profile which the external face of the support panel must match. Then, during a fourth step, the support panel is placed in an appropriate tool making it possible to constrain it according to a position similar to that which it must occupy once mounted in the casing.

During a fifth step, the external face of the support panel is then machined according to a three-dimensional profile corresponding to that of the internal face of the casing. These stages constitute the stages of manufacture of the support panel, and therefore constitute a first stage of manufacture of the housing with abradable coating. Then, during a second phase of manufacturing the housing with an abradable coating, the support panel is bonded to the housing and the abradable material on the support panel.

This design has the drawback of requiring a measurement operation of the internal face of the casing with very high tolerances because the slightest defect in shape of the internal face of the casing panel has consequences on the positioning of the support panel after its fixing. .

Furthermore, the machining operation is moreover very restrictive due to the tools which are used for its production. Indeed, once cooked, the support panel is considerably stiffened, this rigidity being provided mainly by the skin of composite material. The stressing of the support panel in the tooling in order to constrain it in the position which it must occupy once mounted in the casing implies a tooling capable of imparting the appropriate deformations while ensuring high support for the support panel. This tool is therefore complex and expensive.

Furthermore, to obtain satisfactory adhesion of the skin of composite material to the block of honeycomb material, it is necessary to bake the assembly in half-sandwich in an autoclave enclosure. Consequently, the mass production of such supports of cartridges of abradable material implies rigorous management of the times of use of the autoclave chambers, which complicates the production of these panels.

Finally, the insertion of an intumescent material between the edges of the block of honeycomb material and the edges of the skin of composite material presents risks of deformation of the support panel. Indeed, the expansion of the intumescent has a direct impact on the quality of the songs. The support panels produced according to the current state of the art notably comprise craters, porosities, and delaminations at the edges, which almost always requires retouching the edges to obtain the final support panel.

To overcome these drawbacks, it is desirable to allow the support panel to be manufactured using conventional cooking means and to allow the block of honeycomb material to be machined with reduced tooling and to lower tolerances.

STATEMENT OF THE INVENTION

The invention therefore aims to simplify the operations of preparing the raw support panel and its machining in order to adapt it to the internal surface of the casing.

• une étape d'usinage de la face externe du bloc de matériau selon un profil en trois dimensions configuré pour épouser celui de la face interne du carter, puis
• une étape de fixation du bloc usiné à la peau rigide.

To this end, the invention provides a method of manufacturing at least one support panel for a cartridge of abradable material for a turbomachine casing, said panel comprising at least one block of material, in particular honeycomb, and a rigid skin covering said block with the exception of a free external face configured to be fixed to an internal face of the casing, characterized in that it comprises:

• a step of machining the external face of the block of material according to a three-dimensional profile configured to match that of the internal face of the casing, then
• a step of fixing the machined block to the rigid skin.

This new organization of the stages of the manufacturing process of the support element makes it possible, because of the stage of machining the material prior to its insertion into the rigid skin, to simplify this stage of machining since it can be performed without the obligation to have specific tools necessary to constrain the support element according to the shape it will occupy in the housing. Furthermore, the fixing of the block of material in the rigid skin makes it possible to avoid the use of an intumescent material and therefore eliminates the defects that it was capable, in the prior art, of causing. level of these songs.

• au cours de l'étape d'usinage on usine la face externe du bloc jusqu'à une épaisseur déterminée et préalablement à l'étape de fixation, on choisit une peau rigide comportant une paroi et des rebords définissant des chants de hauteur déterminée inférieure à l'épaisseur déterminée du bloc,
• au cours de l'étape de fixation, on colle la paroi de la peau en matériau composite sur une face interne du bloc et les chants sur les bords dudit bloc,
• le procédé comporte une étape préalable de fabrication de la peau par cuisson d'un matériau composite imprégné,
• le procédé comporte une étape préalable de mesure de dimensions d'une face interne du carter pour déterminer le profil en trois dimensions de ladite face interne.

According to other characteristics of the method for manufacturing the support element:

• during the machining step, the external face of the block is machined to a predetermined thickness and prior to the fixing step, a rigid skin is chosen comprising a wall and flanges defining edges of determined height less than the determined thickness of the block,
• during the fixing step, the wall of the skin of composite material is bonded to an internal face of the block and the edges on the edges of said block,
• the method comprises a prior step of manufacturing the skin by baking an impregnated composite material,
• the method comprises a preliminary step of measuring the dimensions of an internal face of the casing to determine the three-dimensional profile of said internal face.

The invention also provides a support panel for at least one cartridge of abradable material for a turbomachine, said panel comprising at least one block of a material, in particular honeycomb, which has an external face configured to be bonded to an internal face of a turbomachine casing and which is covered with a rigid skin, said rigid skin comprising a wall covering an internal face of the block and flanges defining edges facing the lateral edges of said block, characterized in that the external face of the block is machined and in that the rigid skin is fixed to the block by means of an adhesive film, said adhesive film being inserted between the wall of the skin and the internal face of the block and between the edges of the skin and the lateral edges of said block.

• une extrémité libre des chants est agencée en retrait de la face externe du bloc,
• la peau est un matériau composite imprégné cuit.

According to other characteristics of the panel:

• a free end of the edges is set back from the external face of the block,
• the skin is a baked impregnated composite material.

The invention also proposes a method for manufacturing a casing with an abradable coating of a turbomachine, comprising a turbomachine casing coated with a support panel of the type described above receiving a cartridge of abradable material, characterized in that it successively comprises a first phase during which the steps of the method of manufacturing a support panel are implemented as described above to obtain at least one support panel, a second phase during which said support panel is bonded to the internal face of the casing, and a phase during which a cartridge of abradable material is bonded to said support panel.

According to another characteristic of the process for manufacturing the housing with abradable coating, the second phase of said process takes place simultaneously with the bonding step of the process for manufacturing the support panel,

The invention finally relates to a turbomachine comprising at least one casing with abradable coating obtained by the method described above.

• la figure 1 est une vue schématique en coupe d'un carter à revêtement abradable de turbomachine selon un état antérieur de la technique;
• les figures 2A et 2B sont des vues schématiques représentant une partie des étapes d'un procédé de fabrication d'un panneau de support selon un état antérieur de la technique ;
• la figure 3 est une vue schématique représentant une phase finale d'un procédé de fabrication du carter à revêtement abradable de la figure 1 ;
• la figure 4 est un organigramme représentant les phases d'un procédé de fabrication du carter à revêtement abradable de la figure 1 ;
• la figure 5 est une vue schématique en coupe d'un carter à revêtement abradable selon l'invention ;
• la figure 6A et 6B sont des vues schématiques représentant une partie des étapes d'un procédé de fabrication d'un panneau de support selon l'invention ;
• la figure 7 est une vue schématique représentant une phase finale d'un procédé de fabrication du carter à revêtement abradable de la figure 5.
• la figure 8 est un organigramme représentant les phases d'un procédé de fabrication du carter à revêtement abradable de la figure 5.

The invention will be better understood and other details, characteristics and advantages of the present invention will appear more clearly on reading the following description given by way of nonlimiting example and with reference to the appended drawings, in which:

• the figure 1 is a schematic sectional view of a casing with an abradable coating of a turbomachine according to a prior art;
• the Figures 2A and 2B are schematic views showing part of the steps of a method of manufacturing a support panel according to a prior art;
• the figure 3 is a schematic view showing a final phase of a process for manufacturing the abradable coating casing of the figure 1 ;
• the figure 4 is a flowchart representing the phases of a process for manufacturing the abradable-coated housing of the figure 1 ;
• the figure 5 is a schematic sectional view of a housing with abradable coating according to the invention;
• the Figure 6A and 6B are schematic views showing part of the steps of a method of manufacturing a support panel according to the invention;
• the figure 7 is a schematic view showing a final phase of a process for manufacturing the abradable-coated casing of the figure 5 .
• the figure 8 is a flowchart representing the phases of a process for manufacturing the abradable-coated housing of the figure 5 .

In the following description, identical reference numerals denote parts that are identical or have similar functions.

In the remainder of this description, the “internal” and “external” orientations are defined by reference to an axis of rotation of the rotors of a turbomachine, the “external” orientations being turned opposite to said axis, and the orientations "Internal" being turned towards said axis.

We have represented in figures 1 and 5 a housing with abradable coating 10 for a turbomachine.

In known manner, such an abradable casing 10 comprises a bare casing 12 which is coated with a support panel 14 which is itself coated with a cartridge 16 made of abradable material.

The support panel 14 comprises at least one block 18 of honeycomb material, generally known under the name of " Nida ”, and a rigid skin 20 which covers the block 18 and which is intended to receive the cartridge 16 made of abradable material.

Thus, the support panel 14 is shaped in the form of a half-sandwich which is fixed to an internal face 13 of the casing 12 by means of an adhesive film 22.

The cartridge of abradable material 16 is fixed to the support element 14 by gluing, and in particular by baking the abradable material. The cooking of the abradable material ensures its cohesion with the support panel 14.

The figure 1 more particularly illustrates a housing with abradable coating 10 produced in accordance with a prior art. This housing with abradable coating 10 comprises in particular a support panel 14 which is produced according to a method which has been shown in Figures 2A and 2B in correspondence of the stages of the figure 4 .

According to this method, during a first step ET1 which has been shown in the figure 2A , a block 18 of honeycomb material is inserted into a skin preform 26 made of impregnated composite material, for example a preform 26 made of woven carbon fibers and impregnated with an epoxy resin. The preform 26 has a wall 28 and flanges defining edges 30. When the block 18 of honeycomb material is inserted into the preform, an intumescent material 32 is interposed between edges 34 of the block 18 of honeycomb and the edges 30 of the preform 26.

The assembly, shaped substantially in the form of a half-sandwich, is subjected to a simple baking during a second step ET2 so as to form a raw support panel.

At the end of this step ET2, the skin preform 26 of composite material has become a rigid skin 20 as shown in FIG. figure 2B . The block 18 of honeycomb material, the intumescent material 32, and the skin 20 are adhered to each other following the curing of the composite material.

Furthermore, the internal surface 13 of the casing 12 previously shown in the figure 1 does not necessarily correspond to its theoretical profile. In particular, in the case of a casing 12 of revolution made of composite material, it has been found that the internal face 13 of the casing 12 after manufacture may not have a perfectly circular section but rather an ovalized section unsuitable for receiving a wheel. compressor or turbine of the turbomachine (not shown). In addition, the internal face 13 of the casing 12 may have possible surface defects.

Insofar as the skin 20 is rigid and its general shape must no longer be modified since it must have a minimum thickness enabling it to support the cartridge of abradable material 16, it is therefore necessary to carry out machining on one side external 36 of the support panel 14 so that it matches the internal face 13 of the casing 12 in order to minimize the deformations that the support panel 14 could undergo relative to its theoretical profile. Indeed, such deformations would have the consequence of modifying the position required for the support panel 14, and consequently for the cartridge of abradable material 16 that the support panel 14 must receive.

To do this, as illustrated in figure 4 , during a third step ET3 (not shown), the internal face 13 of the casing 12 is measured so as to deduce therefrom a three-dimensional profile which the external face 36 of the support panel 14 must match. Then, during a fourth step ET4, the support panel 14 is placed in an appropriate tool (not visible) which makes it possible to constrain the panel 14 to a position similar to that which it must occupy once mounted in the housing. 12.

For example, this constraint may consist, when the panel 14 has an annular shape, in a radial constraint acting along the entire periphery of the external face 36 of the panel 14 or, when the panel 14 has an angular sector shape as shown to the Figures 2A and 2B , in a stress exerted radially on the periphery of the external face 36 and tangentially on the edges 30 of the panel 14, because the panel 14 is intended to be arranged between two panels 14 of the same type which consequently exert on it tangential forces at the level of these two edges 30.

It will be understood that other constraints can be exerted to constrain the panel 14 to its position mounted in the casing 12, without limitation of the invention.

Then, during a fifth step ET5 which was represented at figure 2B , the external face 36 of the support panel 14 is then machined according to a three-dimensional profile corresponding to that of the internal face 13 of the casing 12, for example using a two-size cutter 37.

The first to fifth steps ET1 to ET5 of the process for manufacturing the support panel 14, comprising in particular the steps ET1 and ET5 which have been shown in Figures 2A and 2B , constitute a first phase P1 of the process for manufacturing the housing with abradable coating. Then, during a second phase P2 represented at figure 4 and illustrated in figure 3 , the support panel 14 is bonded to the internal face 13 of the casing and finally during a phase P3, the cartridge 16 of abradable material is bonded to the support panel 14

These methods have several drawbacks.

First, they impose, during step ET3, an operation of measuring the internal face 13 of the casing 12 with very high tolerances, because, like the support panel 14 is made rigid at the end of the cooking step ET2 of the skin 20, the slightest defect in shape of the internal face 13 of the casing panel 12 results in a positioning defect of the support panel 14 after it has been fixed on the casing 12.

In particular, as the figure 1 , the external ends 38 of the edges 30 being directly in contact with the internal face 13 of the casing 12, any defect in this internal face 13 causes a defect in positioning of the wall 28 of the support panel 14, and consequently of the cartridge 16 of abradable material.

Secondly, the machining operation of step ET5 is moreover very constraining to implement due to the nature of the tools which it implies. As we have seen, once cooked, the support panel 14 is considerably stiffened by the skin 20 made of composite material. The stressing of the support panel 14 in the tooling in order to constrain it in the position which it must occupy once mounted in the casing implies a tooling capable of imparting the appropriate deformations of the panel 14 while ensuring that the 'it does not escape from said high tooling of the support panel.

Third, the second cooking step is also problematic. Indeed, as the connection of the block 18 to the skin 20 is carried out by cooking the support panel 14 in its entirety, it is necessary to cook this assembly in half-sandwich in an autoclave enclosure. Consequently, the mass production of such supports 14 of cartridges of abradable material implies rigorous management of the times of use and occupation of the autoclave chambers, which complicates the management of production flows.

Finally, the insertion of the intumescent material 32 between the edges of the block of honeycomb material and the edges of the skin of composite material increases the risks of deformation of the support panel 14. Indeed, the expansion of the intumescent can produce craters, porosities, and delaminations at the edges 30, which almost always requires retouching the edges 30 to obtain the final support panel 14.

This drawback is remedied by proposing a method for manufacturing the support panel 14 and a method for manufacturing the housing with abradable coating 10 which advantageously allow the manufacture of the support panel 14 using conventional cooking means and allowing the machining of the block 18 of honeycomb material with reduced tooling and according to lower tolerances.

In accordance with the invention, as illustrated by Figures 6A, 6B and 7 , the method successively comprises at least one step ET5 ′ of machining the external face 36 of the block 18 of honeycomb material according to a three-dimensional profile configured to match that of an internal face of the casing, then a step ET6 ′ for bonding the block 18 machined to the rigid skin 20.

The implementation of this process can presuppose the supply of a rigid skin 20 which can already be formed, and for example be part of a stock of skins 20 available to the operator in charge of manufacturing, or as a variant , of a skin which is formed at the time of the implementation of the process. We will now describe a preferred embodiment of the method, it being understood that this embodiment is, in its organization, not limiting of the invention, as long as the method comprises at least the step of machining the outer face 36 of the block 18 and the step of bonding the block 18 machined to the rigid skin 20.

As the figure 8 , the method of manufacturing the support panel 14 according to the invention preferably comprises a first step ET1 ′, during which the skin 20 is made of composite material by baking an impregnated composite material, for example a fabric of fibers carbon impregnated with epoxy resin. This gives a skin 20, preferably rigid, comprising a wall 28 and edges 30, as shown in the figure 6A . The skin 20 is configured to leave free on the block 18 an external face 36 configured to be fixed to an internal face 13 of the casing 12 as shown in the figure 5 .

Then, or in parallel, since these operations can be carried out simultaneously, the method comprises a step ET2 'of cutting the block 18 of honeycomb material according to dimensions suitable for adapting to those of the wall 28 of the skin 20 , the purpose of this operation being obviously to guarantee that the block 18 can be covered by the skin 20.

Then or in parallel, since these operations can be carried out simultaneously, the method preferably includes a third step ET3 'of measuring the internal face 13 of the casing 12 to determine the three-dimensional profile of said internal face 13. This third step ET3' of the method is not limiting of the invention but it nevertheless makes it possible to characterize very precisely the profile of the internal face 13 in order to precisely measure all the defects.

Then, during a fourth step ET4 ′, the block 18 is placed in position on a tool (not visible) capable of giving it a position corresponding to the final position that it is intended to occupy in the panel 14 mounted in the housing 12.

Advantageously, since the block 18 is not stiffened by the rigid skin 20, the tooling used does not require prestressing the block 18 in order to obtain the final position which it is intended to occupy in the panel 14 mounted in the casing 12 This configuration allows the use of simpler tools.

Then, at least one step ET5 ′ is carried out of machining the external face 36 of the block 18 made of honeycomb material according to a three-dimensional profile configured to match that of the internal face 13 of the casing 12, as shown in the figure 6B .

Compared to the method as described above with reference to the state of the art, this method advantageously makes it possible to machine a block 18 of honeycomb material which is more flexible than previously, because it is not stiffened by the rigid skin 20. As a result, the machining can advantageously be carried out as previously with a two-size cutter 37, but it is not necessary to have a tool making it possible to constrain and precisely maintain the block 18 of honeycomb material, because it is not stiffened by the skin 20 and is therefore more flexible.

Then, as the figure 7 , during a bonding step ET6 ′, the block of honeycomb material 18 previously machined to the skin 20 is fixed by means of an adhesive film 40.

Preferably, an external face 27 of the wall 28 of the skin of composite material 20 is bonded by means of the adhesive film 40 to an internal face 42 of the block 18 of honeycomb material and the edges 30 on the edges 34 of said block 18 of honeycomb material.

Advantageously, in the preferred embodiment of the method for manufacturing the support element 14, the block 18 of honeycomb material is machined during step ET5 ′ to a thickness E1, shown in the figure 6B .

During the first step ET1 ′, a rigid skin 20 is made or chosen, having flanges defining edges 30 of determined height H, as shown in FIG. figure 6A . The height H of the edges 30 is provided to be less than the height E1 of the block 18.

This configuration is particularly advantageous. In fact, the support panel 14 obtained has edges 30 whose free end is therefore capable of being arranged set back from the plane of the external face 36 of the block 18.

This configuration makes it possible to guarantee that, when the block 18 of honeycomb material is assembled with the rigid skin 20, the external ends 38 of the edges 30 do not come to touch the internal face 13 of the casing 12, as represented by the reference detail and the associated arrow shown in the figure 7 . Thus, any residual defect of the internal face 13 of the casing 12 is not transmitted by the rigid skin 20 to its wall 28, and has no consequences on the positioning of its wall 28.

In addition, this configuration allows the use of a standard composite skin 20 whose edges 30 do not require any machining. A simple choice of the composite skin in a stock of composite can of different heights makes it possible to find the one whose height H can be adapted to block 18 without the height of its edges 30 exceeding the height E1 of block 18.

The first to fifth steps ET1 'to ET6' of the process for manufacturing the support panel 14 according to the invention, comprising in particular the steps ET1 'and ET5' which have been shown in Figures 6A and 6B , constitute a first phase P1 ′ of the process for manufacturing the housing with abradable coating 10. Finally, during a second phase P2 ′ of the process for manufacturing the housing with abradable coating 10 which has been shown in FIG. figure 8 and illustrated in figure 7 , the support panel 14 is bonded to the internal face 13 of the casing and during a third phase P3 ', the cartridge 16 of abradable material is bonded to the support panel 14.

Advantageously, as illustrated by the variant of the process in dotted lines of the figure 8 , the sixth step ET6 'of manufacturing the support panel 14 may coincide with the second phase P2' of the method of manufacturing the housing with abradable coating 10, insofar as the bonding of the block 18 in the skin 20 can be carried out in one single operation at the same time as that of the external face 36 of the block 18 on the internal face 13 of the casing 12. The grouping of the bonding operations therefore makes it possible to avoid adding an additional step to the process, which retains the same number of stages as the methods according to the state of the art, while avoiding its drawbacks and without requiring independent cooking for fixing the skin 20 to the block 18 and for fixing the block 20 to the casing 12.

The invention is particularly applicable to a support panel 14 intended to equip a housing with abradable coating 10 of a turbomachine, whether it is a housing with abradable coating 10 intended for a compressor stream or turbine of said turbomachine.

Claims (11)

1. Method for manufacturing a panel (14) for supporting at least one cartridge (16) of abradable material for a turbine engine casing, said panel (14) including at least one block (18) of material and a rigid panel (20) covering said block, except for a free outer surface (36) configured to be fixed to an inner surface (13) of the casing (12), characterised in that it includes:

   - a step of machining (ET5') the outer surface (36) of the block (18) of material according to a three-dimensional profile configured to match that of the inner surface (13) of the casing (12), then

   - a step of fixing (ET6') the machined block (18) to the rigid panel (20).
2. Method according to the preceding claim, characterised in that during the machining step (ET5'), the outer surface of the block (18) is machined up to a determined thickness (E2), and in that, prior to the fixing step (ET6'), a rigid panel (20) including a wall (28) and edges defining rims (30) of determined height (H) less than said determined thickness (E2) of the block (18) are selected.
3. Method according to the preceding claim, characterised in that, during the fixing step (ET6'), the wall (28) of the panel (20) is adhered onto an inner surface (42) of the block (18) and the rims (30) onto the edges (34) of said block (18).
4. Method according to one of the preceding claims, characterised in that it includes a prior step (ET1') of manufacturing the panel (20) by cooking an impregnated composite material.
5. Method according to one of the preceding claims, characterised in that it includes a prior step (ET3') of measuring dimensions of an inner surface (13) of the casing (12) to determine the three-dimensional profile of said inner surface.
6. Panel (14) for supporting at least one cartridge (16) of abradable material (16) for a turbine engine, said panel (14) including at least one block (18) of material which includes an outer surface (36) configured to be adhered to an inner surface (13) of a turbine engine casing and which is covered with a rigid panel (20), said rigid panel including a wall (28) covering an inner surface (42) of the block (18) and edges defining rims (30) in regard to edges (34) of said block (18),
   characterised in that the outer surface (36) of the block (18) is machined and in that the rigid panel (20) is fixed to the block (18) by way of an adhesive film (24), said adhesive film (24) being interleaved between the wall (28) of the panel (20) and the inner surface (42) of the block (18) and between the rims of the panel (30) and the side edges (34) of said block (18).
7. Panel (14) according to claim 6, characterised in that a free end (38) of the rims (30) is arranged set back from the outer surface (36) of the block (18).
8. Panel (14) according to one of claims 6 or 7, characterised in that the panel (20) is made of a cooked, impregnated composite material.
9. Method for manufacturing a turbine engine casing with abradable coating (10), including a turbine engine casing (12) covered with a panel (14) according to claims 6 to 8 receiving a cartridge (16) of abradable material, characterised in that it successively includes a first phase (P1') during which the steps (ET5', ET6') of the method for manufacturing a panel according to one of claims 1 to 5 are implemented, to obtain at least one panel (14), a second phase (P2') during which said panel (14) is adhered on the inner surface (13) of the casing (12), and a third phase (P3') during which a cartridge (16) made of abradable material is adhered on said panel (14).
10. Method for manufacturing a casing with abradable coating (10) according to the preceding claim, characterised in that the second phase (P2') of said method occurs simultaneously with the adhering step (ET6') of the method for manufacturing the panel (14).
11. Turbine engine including at least one panel (14) according to one of claims 6 to 8 obtained by the method according to one of claims 1 to 5.

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