EP2828413A1

EP2828413A1 - Holding tool for the heat treatment of metal parts

Info

Publication number: EP2828413A1
Application number: EP13715340.9A
Authority: EP
Inventors: Frédéric Guichard; Jean-Pierre Maumus
Original assignee: Herakles SA
Current assignee: ArianeGroup SAS
Priority date: 2012-03-23
Filing date: 2013-03-18
Publication date: 2015-01-28
Anticipated expiration: 2033-03-18
Also published as: RU2014138592A; FR2988401A1; EP2828413B1; BR112014023582A2; MX349753B; MX2014011330A; CN104245969A; CN104245969B; ES2613077T3; WO2013140072A1; CA2867642A1; RU2630075C2; FR2988401B1; US20130252191A1; BR112014023582A8; US9903656B2

Abstract

The invention concerns a holding tool (100) for at least one part (150) made from metal material intended to be heat treated or hot shaped, said tool comprising: - a fixed support structure (110) having a determined shape corresponding to the general shape of each part made from metal material to be held, - first holding elements (1161-1261) disposed to one side of each part, - second holding elements (1162-1262) disposed to the other side of each part, - at least one elastic spring element (130-134) placed between the support structure (110) and each first or second holding element (1161-1261; 1162-1262) so as to hold the part for the entire duration of a heat treatment. The support structure (110), the first and second holding elements (1161-1261, 1162-1262) and the elastic element or elements (130-134) are made from a thermostructural composite material.

Description

Tooling for heat treatment of metal parts

Background of the invention

The present invention relates to holding tools used to hold metal parts during heat treatments of such parts such as annealing, brazing, conformations, etc.

Heat treatments of parts made of metallic material, such as titanium or other, are carried out at high temperatures that may exceed 1000 ° C. In the case of titanium parts, for example, it is common to subject the part during its manufacture a heat treatment called "annealing" at temperatures where the titanium becomes soft. In this case, the titanium piece deforms (flue) under the effect of simple gravity and remains deformed after cooling. The part can also be twisted during temperature drops by releasing internal stresses.

Also, very heavy monobloc metal supports, made for example of refractory steel, are generally used to maintain the workpiece during heat treatment. However, the use of such media has several disadvantages.

First of all, these supports are usually very bulky and heavy. They reduce, therefore, the loading capacity of the oven used for heat treatments while being difficult to handle. They also have a significant thermal inertia, which results in significant energy consumption for the temperature setting of the tool and requires a long cooling time reducing the productivity of the installation. In addition, this significant thermal inertia limits the thermal gradients needed to obtain the desired microstructure. This type of support also has a high coefficient of thermal expansion, most of the time different from that of the material of the part to be treated, which limits its use to parts having simple geometric shapes and requires the provision of rework. machining on the parts to conform to their final geometry.

Finally, this type of support is deformed during heat treatments due to repeated thermal shocks.

Object and summary of the invention

The present invention therefore aims to provide a new holding tool for metal material parts to be heat treated which, in addition to being lighter, less bulky and reduce the thermal inertia in the oven , makes it possible to respect precisely the geometries of the pieces, from the simplest to the most complex, and this even in case of movements of these last ones during the variations of temperature. Another object of the invention is to provide a tool that does not flow during heat treatments and retains its mechanical characteristics over time.

There is, moreover, a need to have a tool capable of hot conforming a part that was out of cold tolerance.

For this purpose, the invention proposes a holding tool comprising:

a fixed support structure having a specific shape corresponding to the general shape of each piece of metal material to be maintained,

first holding elements arranged on one side of each part,

second holding elements arranged on the other side of each piece,

at least one elastic element of spring type placed between the support structure and each first or second holding element so as to ensure the maintenance of the part throughout a heat treatment,

the support structure, the first and second holding elements and the spring elements being made of thermostructural composite material, for example a carbon / carbon or ceramic matrix (CMC) composite material. The tooling of the invention implements an elastic holding of a metal part in a housing respecting the final geometry of the part, which allows the maintenance or compliance of the part in its precise geometry during heat treatments . The structure defining the housing and the elements of the holding system being of thermostructural composite material, that is to say a material having a very low coefficient of thermal expansion, the tool undergoes very little deformation during temperature variations. and the spring elements have a stiffness, and, therefore, a bearing force on the holding elements, almost constant regardless of the temperature.

Thanks to the elastic holding force exerted on the part in a virtually uniform manner regardless of the temperature, it is possible to conform the latter during the heat treatment and thus correct deformations generated during previous operations performed on the part as pre-machining closer to the final rib. Indeed, the principle of elastic retention of the workpiece in the tool of the invention allows to mount therein a relatively deformed piece which will not be initially (ie cold) in contact with all the holding elements of reference but which, once in temperature, will be constrained by the spring elements and therefore conform to the desired geometry. Such hot conforming would be very difficult to implement with a metal tool.

Thanks to the thermostructural composite material used for the realization of the constituent elements of the tool of the invention, it is much less bulky and heavy than the usual refractory steel tools. The tooling of the invention thus makes it possible to increase the loading capacity of metal parts to be treated in the same furnace, which makes it possible to reduce the costs of the heat treatments. It also makes it possible to reduce the number of manipulations and treatments for a given number of parts, which makes it possible to significantly reduce the costs of heat treatments.

According to one embodiment of the invention, the tooling comprises a plurality of pairs of jaws placed on each side of the metal part, each pair of jaws being slidably mounted on the support structure. The movements of the room during mounted or lowered in temperature, can be accompanied by the jaws without exerting stress on the workpiece and while following the precise geometry of the latter defined by the support structure of the tooling.

For this purpose, each jaw is provided with at least one guide cooperating with a slideway formed in the support structure. According to one embodiment of the invention, the side walls of the support structure comprise at least one slide intended to receive a guide of a jaw of a pair of jaws, spring elements being interposed between at least one jaw of each pair of jaws and the side walls of the support structure.

According to a feature of the invention, the support structure has a housing having at least a first portion extending in a first plane and a second portion extending in a second plane forming an angle with the first plane. It is thus possible to maintain and conform the same piece in different planes forming between them angles in one or more directions.

This configuration of variable planar geometry maintenance tooling can also be obtained with a support structure having a housing extending in the same first plane and at least a portion of which is provided with angular spacers arranged between one or more pairs of jaws and the side walls of the support structure so that the part of the housing present between the angular wedges extends in a second plane forming an angle with the first plane.

According to another embodiment of the invention, the tooling comprises a plurality of spacer elements interposed between first and second metal parts and a plurality of jaws placed against the first metal part and support plates placed against the second metal part, the spring elements being interposed between the jaws and the support structure.

According to one characteristic of this embodiment, the spring elements are connected to the jaws by first articulated links and to the support structure by second links. articulated, the spacer elements resting on movable carriages on the support structure and the support plates being held against rollers integral with the support structure. In this way, all the holding elements are able to move with the metal parts relative to the fixed support structure and can thus accompany the movements of the parts during temperature changes.

According to a particular characteristic of the invention, the support structure, the first and second holding elements and each spring-type elastic element are made of carbon / carbon composite material.

According to one aspect of the invention, each elastic member has a predetermined cold stiffness which defines the holding force applied by the jaws to the workpiece, and this for an extended temperature range because the spring element is made of thermostructural composite material .

The invention also relates to a heat treatment installation comprising an oven and one or more holding tools according to the invention placed inside the oven.

Brief description of the drawings

Other characteristics and advantages of the invention will emerge from the following description of particular embodiments of the invention, given by way of non-limiting examples, with reference to the appended drawings, in which:

FIG. 1 is a schematic perspective view of a heat treatment installation comprising holding tools according to the invention,

FIG. 2 is an exploded view of a holding tool according to one embodiment of the invention;

- Figure 3 is a schematic perspective view of the holding tool of Figure 2 once mounted; FIG. 4 is a sectional view of part of the holding tool of FIG. 3 represented in FIG. 5;

FIG. 5 is a side view of part of the holding tool of FIG. 3;

FIGS. 6A and 6B are schematic views of a tool for holding a workpiece in several planes oriented in different directions in accordance with one embodiment of the invention;

FIG. 7 is a schematic view of a tool for holding a workpiece in several planes oriented in different directions in accordance with another embodiment of the invention;

FIGS. 8A and 8B are detailed views of parts of the holding tool of FIG. 7;

FIG. 9 is a schematic perspective view of a holding tool according to another embodiment of the invention;

FIG. 10 is an exploded view of the holding tool of FIG. 9;

FIG. 11 is a sectional view of the tool of FIG. 9.

Detailed description of an embodiment

The invention applies generally to tools for maintaining metal parts in precise geometry during processing involving temperature rises, such as annealing, quenching, tempering, maturing, conformations or hot brazing. or any other treatment involving temperature variations. A particular, but not exclusive, field of application of the invention is that of the hot conformation of titanium or similar parts of large size and whose geometry must be very precisely respected or heat recovery (conforming parts out of tolerance Cold).

FIG. 1 illustrates an installation 300 intended to heat-treat parts made of metallic material whose geometry must be precisely respected throughout the treatment. The 300 installation comprises an oven 200 and a plurality of holding tools 100 resting on a base 101.

As illustrated in Figures 2 and 3, each holding tool 100 comprises a support structure 110. In the example described here, the structure 110 consists of a frame 111, formed by two cross members 1110 and 1111, and walls side 1120 to 1124 and 1140 to 1144 held above the frame 111 by uprights 114. The space between the side walls 1120 to 1124, on the one hand, and the side walls 1140 to 1144, on the other hand, form a housing 115 for a metal part 150 to be heat treated. The shape of the housing 115 corresponds to the general shape of the metal part to be treated 150, namely here a part having in its longitudinal direction a curved shape.

The holding tool 100 also comprises a plurality of pairs of jaws, here pairs of jaws 116 to 126, the jaws 1161 to 1261 located on one side of the part 150 corresponding to all or part of the first holding elements of the jaws. tooling of the invention and the jaws 1162 to 1262 located on the other side of the part corresponding to all or part of the second holding elements of the tool of the invention. Each pair of jaws, like the pair 119 illustrated in Figure 4, is formed of two jaws 1191 and 1192 between which the metal piece 150 is held. For this purpose, the jaws of each pair, like the jaws 1191 and 1192 of the pair 119, each have an inner face 1191a, 1192a whose shape corresponds to the geometry of the part of the part intended to be maintained at this location. tooling.

In order to maintain a holding force on the workpiece in the tooling, resilient spring-like elements are interposed between at least the outer face of one of the jaws of each pair of jaws and the corresponding vertical wall. In the example described here, elastic elements 130 to 134 are respectively interposed between the jaws 1161 to 1261 and the side walls 1140 to 1144, support plates (not shown) which can be further interposed between the spring elements and the jaws. Special tools for holding the elastic elements 130 to 134 respectively in maximum compression is used when mounting the workpiece and jaws in the tooling, the elastic members 130 to 134 then being released to exert a holding force on the jaws and on the workpiece in the tool housing .

The elastic elements 130 to 134 are each constituted respectively by two elastic blades 1301/1302, 1311/1312, 1321/1322, 1331/1332 and 1341/1342 which exert an elastic holding force on each pair of jaws 116 to 126, and this according to the geometry of the housing 115 which corresponds to the precise geometry of the part to be respected.

On the other hand, the jaws 1161/1162 through 1261/1262 of the jaw pairs 116 to 126 are slidably mounted on the sidewalls. For this purpose, each jaw comprises on its outer face a guide engaged in a slide formed in the side wall opposite the jaw considered. In the example described here, the outer walls of the jaws 1161 to 1261 are respectively provided with a guide 1163 to 1263 while the outer walls of the jaws 1162 to 1262 are respectively provided with a guide 1164 to 1264. The guides 1163 to 1263 are respectively engaged in slides 1140a, 1140b, 1141a, 1141b, 1141c, 1142a, 1143a, 1143b, 1143c, 1144a, 1144b of the side walls 1140 to 1144. Similarly, the guides 1164 to 1264 are respectively engaged in slides 1120a , 1120b, 1121a, 1121b, 1121c, 1122a, 1123a, 1123b, 1123c, 1124a, 1124b of the side walls 1120-1124.

As illustrated in Figure 5, the jaw 1191 of the pair of jaws 119 is held on the support structure 110 by means of the guide 1193 which is engaged in the slide 1141b formed in the side wall 1141. The slide 1141b has the form of an oblong hole in which the guide 1193 can move between a first position A corresponding to the position of the cold holding member and a second position B corresponding to the position of the holding member 1191 when the metal piece 150 expands during a rise in temperature. The orientation of the oblong hole of the slide 1131b as well as its position on the side wall 1131 oriented according to the geometry of the piece in the longitudinal direction, here a curved shape, allow the holding system constituted by the holding elements associated with the elastic elements to follow the movements of the part during its expansion and / or retraction by ensuring a conservation of the geometry in the holding plane or planes defined by the housing of the structure of support.

According to the present invention, the elements constituting the holding tool of the present invention as the support structure, the holding elements of each pair and the spring-like elastic elements are made of thermostructural composite material which has a low coefficient of thermal expansion in comparison to metallic materials such as steel.

The constituent elements of the holding tool are preferably made of carbon / carbon (C / C) composite material which, in a known manner, is a material formed of a carbon fiber reinforcement densified by a carbon matrix and which may optionally be provided with a coating such as a ceramic deposit (example SiC). These elements may also be made of ceramic matrix composite material (CMC) which is a material formed of a carbon fiber or ceramic reinforcement densified by an at least partially ceramic matrix, such as the following CMC composite materials:

carbon-carbon / silicon carbide (C / C-SiC) corresponding to a material formed of a reinforcement of carbon fibers and densified by a matrix comprising a carbon phase and a silicon carbide phase,

carbon-carbon carbide (C / SiC) which is a material formed of a reinforcement of carbon fibers densified by a silicon carbide matrix,

- silicon carbide-silicon carbide (SiC / SiC) corresponding to a material formed of a silicon carbide fiber reinforcement densified by a silicon carbide matrix.

The manufacture of composite material parts consisting of a fiber reinforcement densified by a matrix is well known. It mainly comprises the production of a fibrous structure, here made of carbon or ceramic fibers, the shaping of the structure in a shape similar to that of the part to be manufactured (fibrous preform) and the densification of the preform by the matrix. . The fiber preform is the reinforcement of the part whose role is essential vis-à-vis the mechanical properties. The preform is obtained from fibrous textures of carbon fiber or ceramic. The fibrous textures used may be of various natures and forms such as, in particular:

- two-dimensional fabric (2D),

- three-dimensional fabric (3D) obtained by 3D or multilayer weaving,

- braid,

- knit,

- felt,

- Unidirectional web (UD) of son or cables or multidirectional webs (nD) obtained by superposition of several UD webs in different directions and UD web connection between them for example by sewing, by chemical bonding agent or by needling.

It is also possible to use a fibrous structure formed of several superimposed layers of fabric, braid, knit, felt, plies, cables or others, which layers are bonded together, for example by sewing, by implantation of threads or rigid elements or by needling. .

The shaping is performed by weaving, stacking, needling of two-dimensional / three-dimensional strata or layers of cables, etc.

The fiber preform is then densified, in a well-known manner, by liquid and / or gaseous means.

Liquid densification comprises impregnating the preform with a liquid composition containing a precursor of the matrix material. The precursor is usually in the form of a polymer, such as a resin, optionally diluted in a solvent. The transformation of the precursor into carbon or ceramic is carried out by heat treatment after removal of the optional solvent and crosslinking of the polymer. Several successive impregnation cycles can be performed to achieve the desired degree of densification.

A carbon precursor resin may for example be a phenolic type resin. A ceramic precursor resin may be, for example, a polycarbosilane precursor resin of silicon carbide (SiC), or a polysiloxane resin precursor of SiCO, or a polyborocarbosilazane resin precursor of SiCNB, or a polysilazane resin (SiCN).

The impregnation and polymerization operations of carbon precursor resin and / or ceramic precursor resin can be repeated several times if necessary to obtain specific mechanical characteristics.

The densification of the fiber preform may also be carried out, in a known manner, by gaseous method by chemical vapor infiltration of the matrix (CVI). The fiber preform corresponding to the structure to be produced is placed in an oven in which a gaseous reaction phase is admitted. The pressure and the temperature prevailing in the furnace and the composition of the gas phase are chosen so as to allow the diffusion of the gas phase within the porosity of the preform to form the matrix by deposition, at the heart of the material on contact. fibers, of a solid material resulting from a decomposition of a constituent of the gas phase or a reaction between several constituents, unlike the pressure conditions and temperatures specific to the CVD ("Chemical Vapor Deposition") processes which lead to exclusively to a deposit on the surface of the material.

The formation of a carbon matrix can be achieved with hydrocarbon gases such as methane and / or propane giving the carbon by cracking while an SiC matrix can be obtained with methyltrichlorosilane (MTS) giving SiC by decomposition of the MTS.

In the case of a C / C-SiC material, the first carbon phase may be formed with hydrocarbon gases giving the carbon by cracking, the second SiC phase being then deposited on the first carbon phase, for example by decomposition of the MTS.

A densification combining liquid route and gaseous route can also be used to facilitate implementation, limit costs and production cycles while obtaining satisfactory characteristics for the intended use. The elements, like the side walls of the support structure, are then machined in order to form in them the slides and possibly lights to lighten the entire structure and reduce its thermal inertia. Similarly, lights can be machined in the other components of the support structure to further lighten the mass and reduce thermal inertia.

The advantage of using a thermostructural composite material such as C / C for spring-like elastic elements is to be able to maintain a predetermined cold stiffness during temperature rises. The force exerted by the holding element on the part thus remains almost constant, and this independently of temperature variations. In this way, the maintenance or conformation of the part in its final geometry is precisely controlled, even when the material of the piece is flowing under high temperatures.

Furthermore, since the holding elements of the metal part are slidably mounted on the support structure, they adapt to the expansions and shrinkages of the part during climbs and descents in temperature during the heat treatments by following the displacements of the latter while respecting its geometry because the displacements are made according to the housing geometry of the support structure.

The maintenance and conformation of the metal part in the tooling of the invention can be carried out in the same plane as is the case with the holding tool 100 described above which comprises a housing 115 extending into the same plane over the entire length of the housing, that is to say over the entire length of the metal part 150.

However, the holding tool according to the invention can also allow the maintenance and conformation of a metal part in several differently oriented planes. For this purpose, according to a first embodiment, using a holding tool whose support structure defines a non-rectilinear housing thus creating portions extending at different angles. By way of example, as shown diagrammatically in FIG. 6A, a holding tool 400 comprises a support structure (not shown on FIG. FIG. 6A) which defines a housing 415 comprising a first central portion 415a and second and third end portions 415b and 415c extending in different planes from that of the central portion 415a. More specifically, the central portion 415a extends along a plane PI parallel to reference directions X and Z. The end portion 415b extends along a plane P2 forming an angle α with respect to the plane PI in the X direction The end portion 415c extends along a plane P3 forming an angle α2 with respect to the plane PI in the direction X.

In the example described here, the end portions 415b and 415c are "twisted" with respect to the central portion 415a, that is to say that the planes P2 and P3 of these portions extend further into the Y direction respectively forming angles βΐ and β2 with the plane PI of the central portion 415a (Figure 6B).

According to a second variant embodiment illustrated in FIG. 7, the holding and the conformation of a metal part 550, according to the variable planar geometry illustrated in FIGS. 6A and 6B previously described, can be realized by adapting a holding tool comprising a housing extending in the same plane as the tool 100 described above. For this purpose, as illustrated in Figure 7, using a holding tool 500 whose support structure 510 extends in a longitudinal direction in the same plane. Pair of complementary angular wedges 540/541 and 542/543 are arranged at the end portions 511 and 512 of the support structure 510 so as to define a housing 515 having a central portion 515a extending in a plane identical to the plane PI described above in relation to FIGS. 6A and 6B and two end portions 515b and 515c respectively extending along identical planes to the planes P2 and P3 described previously with FIGS. 6A and 6B. As for the tooling 400, the holding tool 500 makes it possible to maintain, at the end portions 511 and 512 of the support structure 510, the metal part 550 in planes forming one or more screw angles at -vis other portions of maintenance of the tooling.

The support structure 510 differs from the support structure 110 described above in that it has a greater width at the end portions 511 and 512 in order to allow the integration of angular wedge pairs 540/541 and 542/543. At the end portion 511 as shown in Fig. 8A, the angular wedge 540 is attached to a side wall 5140 of the support structure while the wedge 541 is attached to the opposing side wall 5120. 5130 support provided with slides 5130a and 5130b to allow movement of the jaws is fixed on the angular wedge 541 with interposition of a spring element 530 ensuring the elastic holding of the workpiece. Also at the end portion 512 as shown in Fig. 8B, the angular wedge 543 is attached to a side wall 5144 of the support structure while the wedge 542 is attached to the opposing side wall 5124. support plate 5134 provided with slides 5134a and 5134b to allow movement of the jaws is fixed on the angular wedge 543 with interposition of a spring element 534 ensuring the elastic holding of the workpiece.

Depending on the planar geometry of the housing of the holding tool and / or the angle, the arrangement and the number of angular wedges used, the tool can maintain and conform a metal part in two or more planes oriented next different angles. According to the invention, the angular wedges are also made of thermostructural composite material, preferably of carbon / carbon composite material.

FIGS. 9 to 11 illustrate a holding tool according to another embodiment which differs from that described above mainly in that the displacements (expansion / retraction) of the part during temperature variations are accompanied by elements of maintenance which are mounted on the tooling by means of mobile links type spherical or rollers.

More specifically, in this embodiment, the holding tool 600 comprises a support structure 610 consisting of a frame 6100 supporting, on one side of the tool, a side wall 6110 provided with rollers 6111 to 6116 and, on the other side of the tooling are studs 6120 to 6125. A central wall 6130 having plates 6131 to 6136 is further mounted on the frame 6100 between the side wall 6110 and the posts 6120 to 6125 (FIG. 10). Tooling 600 is intended to simultaneously hold two metal parts 680 and 690 of the same final geometry. For this purpose, the parts 680 and 690 are placed facing one another by means of spacers 620 to 625 each mounted respectively on a carriage 630 to 635. The carriages 630 to 635 each comprise a roller respectively 6300 to 6350, which rests on a plate, respectively 6131 to 6136 of the central wall 6130.

The part 680 is also maintained on its opposite side to the spacer elements 620 to 625 by support plates 640 to 645 each respectively resting on one of the rollers 6111 to 6116 of the side wall 6110.

The part 690 is held on its opposite side to the spacing elements 620 to 625 by jaws 650 to 655 which respectively comprise lateral portions 6501 to 6551 and horizontal upper portions 6502 to 6552. The jaws 650 to 655 are mounted on the upper side. tooling by articulated spring links. More precisely, resilient elements of the spring type 660 to 665 are respectively interposed between the jaws 650 to 655 and the uprights 6120 to 6125. In addition, the elastic elements 660 to 665 are respectively connected to the jaws 650 to 655 by means of ball joints 6601 to 6651. The elastic elements 660 to 665 are also connected to the uprights 6120 to 6125 of the support structure by ball joints 6602 to 6652. In this way, the spring elements 650 to 655 and the ball joints 6601 to 6651 and 6602 to 6652 form links articulated elastics which allow to exert a holding force both lateral and vertical on the parts 680 and 690. Indeed, as shown in Figure 11 for the jaw 653, the lateral portions 6531 of the jaw 653 exert, under the pressure of the spring element 663, a lateral holding force Fi on the parts 680 and 690 while the horizontal upper portions 6532 of the jaw 6 53 exert, under the pressure of the spring element 663, a vertical holding force Fv on the parts 680 and 690.

In addition to this link articulated at the jaws for tracking the movements of the metal parts during temperature variations, the spacer elements 620 to 625 and the support plates 640 to 645 are also able to accompany the movements of the parts during their maintenance in the tools. Indeed, the spacers 620 to 625 are associated with the carriages 630 to 635 which each rest on one of the plates 6131 to 6136 of the central wall 6130 so as to be movable in the longitudinal direction of the parts. Similarly, the backing plates 640 to 645 are held against the rollers 6111 to 6116 of the sidewall 6110 and can therefore follow the movements of the parts in the tooling.

Tooling 600 thus comprises holding means for maintaining and / or hot-conforming metal parts in a precise geometry while adapting to the expansions and shrinkage of parts during temperature changes.

The constituent elements of the tooling 600 and in particular the support structure 610, the spacer elements 620 to 625, the carriages 630 to 635, the support plates 640 to 645, the rollers 6111 to 6116, the jaws 650 at 655 and the elastic elements 660 to 665 are made of composite material.

The holding tool 600 is particularly suitable for holding large metal parts because it allows to support in a balanced and reliable way parts having a large mass.

Claims

1. holding tool (100) for at least one piece of metal material (150) to be heat-treated or hot-formed, said tool comprising:

a fixed support structure (110) having a specific shape corresponding to the general shape of each piece of metal material to be maintained,

first holding elements (1161-1261) arranged on one side of each piece,

second holding elements (1162-1262) arranged on the other side of each piece,

at least one spring-like elastic element (130-134) placed between the support structure (110) and each first or second holding element (1161-1261; 1162-1262) so as to maintain the workpiece on the entire duration of a heat treatment,

the support structure (110), the first and second holding members (1161-1261, 1162-1262) and the elastic member (s) (130-134) being of thermostructural composite material.

2. Tooling according to claim 1, characterized in that it comprises a plurality of pairs (116-126) of jaws (1161-1261; 1162-1262) placed on each side of the metal piece (150), each jaw being slidably mounted on the support structure.

3. Tooling according to claim 2, characterized in that each jaw (1161; 1162) is provided with at least one guide (1163; 1164) each cooperating with a slide (1140a; 1120a) formed in the support structure.

4. Tooling according to any one of claims 1 to 3, characterized in that each jaw (1191) has an inner face (1191a) intended to come into contact with a portion of the metal part (150), said face having a shape corresponding to the geometry of said part of the piece.

5. Tooling according to any one of claims 1 to 4, characterized in that the support structure has a housing (415) having at least a first portion (415a) extending in a first plane (PI) and a second part (415b) extending in a second plane (P2) forming an angle with the first plane (PI).

6. Tooling according to any one of claims 1 to 5, characterized in that the support structure (510) has a housing (515) extending in the same foreground and in that it comprises at least a part (511) provided with angular wedges (540, 541) disposed between one or more pairs of jaws and the side walls of the support structure so that the portion of the housing (515b) has between the angular wedges (540, 541) ) extends in a second plane forming an angle with the first plane.

Tooling according to claim 1, characterized in that it comprises a plurality of spacer elements (620-625) interposed between first and second metal parts (690, 680) and in that it further comprises a plurality of jaws (650-655) placed against the first metal piece (690) and backing plates (640-64) placed against the second metal piece (680), the spring-like elastic members (660-665) being interposed between the jaws (650-655) and the support structure (610).

Tooling according to claim 7, characterized in that the elastic elements (660-665) are connected to the jaws (650-655) by first articulated links (6601-6651) and to the support structure by second articulated connections. (6601-6651), the spacer members (620-625) resting on movable carriages (630-635) on the support structure (610) and the support plates (640-645) being held against rollers (6111-6116) integral with the support structure.

9. Tooling according to any one of claims 1 to 8, characterized in that the support structure, the first and second holding elements and each spring-type elastic element are made of carbon / carbon composite material or matrix composite material ceramic

10. Tooling according to any one of claims 1 to 9, characterized in that each elastic element of the spring type has a predetermined cold stiffness.

11. Heat treatment plant (300) comprising an oven (200) and one or more holding tools (100) according to any one of claims 1 to 10 placed inside the furnace.