Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C47/00—Making alloys containing metallic or non-metallic fibres or filaments
  • C22C47/02—Pretreatment of the fibres or filaments
  • C22C47/04—Pretreatment of the fibres or filaments by coating, e.g. with a protective or activated covering
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C47/00—Making alloys containing metallic or non-metallic fibres or filaments
  • C22C47/02—Pretreatment of the fibres or filaments
  • C22C47/06—Pretreatment of the fibres or filaments by forming the fibres or filaments into a preformed structure, e.g. using a temporary binder to form a mat-like element
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C47/00—Making alloys containing metallic or non-metallic fibres or filaments
  • C22C47/14—Making alloys containing metallic or non-metallic fibres or filaments by powder metallurgy, i.e. by processing mixtures of metal powder and fibres or filaments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy

Definitions

• the present invention relates to a method of manufacturing a metal part having a reinforcement of metal matrix composite material of the ceramic fiber type in a metal matrix.
• an insert made of composite material with a metal matrix is incorporated in some parts an insert made of composite material with a metal matrix.
• This material comprises ceramic fibers, of silicon carbide for example, embedded in a metal matrix, such as a titanium alloy. Ceramic fibers have the property of a very high tensile strength and compression greater than the metal.
• the metal matrix provides a binder function with the part as well as protection and insulation of the fibers.
• a known method of manufacturing such parts with reinforcement comprises producing a coil of wire coated around a mandrel.
• the coil is then incorporated in a container or metal main body in which a groove forming a housing has been previously machined.
• the depth of the groove is greater than the height of the winding.
• a lid is placed on the container and welded to its periphery.
• the cover has a post complementary shape to that of the groove, and its height is adapted to that of the coil placed in the groove so as to fill the groove.
• a hot isostatic pressing step is then carried out during which the winding is compacted by the tenon.
• the metallic sheaths of the coated wires are welded together and with the walls of the groove by diffusion to form a dense set composed of metal alloy in which the ceramic fibers extend annularly.
• the resulting part is then machined to the desired shape.
• FR 2886290 in the name of Snecma proposes to carry out the winding directly on the body main. Instead of a groove, there are two shoulders in it. The first has a bearing surface for the direct winding of a coated wire. This surface is parallel to the winding direction. When the winding is completed, the groove is reconstructed by placing a piece on the main body which is shaped complementary to that of a second shoulder forming a step relative to the first shoulder. Then we have the cover with the pin on the insert that has just been wound and compacts the whole.
• the present invention therefore aims to improve the manufacture of a part with a reinforcement of this type so as to reduce the cost.
• the method according to the invention for manufacturing a metal part comprising a ceramic fiber reinforcement comprises the following steps: forming an insert by assembling metal-coated ceramic fibers, preparing a hollow metal mold whose internal volume corresponds to the envelope of the part to be embodied incorporation of the insert in the metal mold so that the insert is spaced from the walls of the mold, filling the mold with a metal powder, closure of the mold by a cover with setting vacuum of the enclosure and welding of the lid to the mold, hot isostatic compression of the assembly, at a temperature and pressure sufficient to deform the mold shell, compact the powder and the fibers, bind the powder particles and the fibers, removal of the mold and machining where appropriate to the desired shape.
• the geometry of the piece resulting from the process can be chosen so that it is closer to the final piece, requiring no or little machining operation.
• the method allows the use of one or more inserts of various shapes depending on the shape of the piece and the desired reinforcement. Each insert can thus be annular. It may be more particularly axisymmetric or have at least one rectilinear portion. When the insert is rectilinear, in the form of a straight segment, it has preferably been formed from coated yarns subjected to hot isostatic compression treatment together.
• the arrangement is a function of the structure of the part to be manufactured and the expected mechanical properties.
• pads are provided inside the mold which reduce the volume to be filled by the metal powder in the areas where the material will be removed by machining. These pads delimit cavities in said metal part between the zones reinforced by the ceramic fibers.
• Patent EP 1 669 144 is known which relates to the manufacture of a metal article, such as a hollow fan blade with internal reinforcement by powder metallurgy as well. However, the process involves the production of a preform and the shaping of the latter to make the hollow article. Such a method is not suitable for the implementation of the invention.
• GB 2,280,909 which relates to the manufacture of a metal part comprising reinforcements of ceramic fibers.
• the coated metal fibers are wound on a support.
• the whole is covered with a sheet and the whole is subjected to hot isostatic compression.
• EP 997.549 and DE 4.335.557 do not disclose the formation of an insert from a plurality of fibers.
• FIG. 1 represents a container of the prior art for producing an elongated piece and with an insert made of a ceramic matrix composite material
• Figure 2 shows a top view of a mold for producing parts according to the invention without its cover.
• FIG. 3 is a side view in longitudinal section of the mold of FIG. 2.
• FIG. 4 is a side view in longitudinal section of another embodiment of the insert in the mold.
• FIG. 5 is a side view in longitudinal section of a variant of a mold for obtaining a part having more material.
• FIG. 6 represents the part obtained in a mold of the type of FIG. 5, seen in transparency and with a part torn off.
• Figure 7 shows a side view in longitudinal section another mold variant for obtaining a symmetrical part.
• FIG. 8 represents the part obtained in a mold of the type of FIG. 7, seen in transparency and with a part torn off.
• FIG. 9 represents the part obtained in a mold of the type of that of FIGS. 2, 3, 4 and 5, seen in transparency.
• FIG. 1 there is shown a container 4 of the prior art, of elongate shape, for producing a part with insert of composite material with a metal matrix.
• a groove 41 has been machined in the container to receive an insert 3.
• the groove and the insert are of complementary shape so that the insert is fit without play in the groove.
• a cover 5 covers the assembly and has a projecting surface not visible in the figure to form a bearing on the insert in the groove.
• the assembly is evacuated, the lid is electron beam welded for example. Then the assembly is placed in a suitable chamber where it is carried out isostatic hot pressing by subjecting it to a high pressure and a high temperature (1000 0 C and 1000 bar).
• the manufacturing techniques with an insert comprising at least one rectilinear portion are described in patent applications FR 07/05453 and FR 07/05454 of July 26, 2007 in the name of the applicant.
• the blank thus produced is then machined to obtain the desired shape.
• parts having complex shapes such as aircraft landing gear elements can be obtained.
• the solution of the invention makes it possible to obtain such parts more economically.
• a steel mold is prepared with a hollow shape close to that of the part to be manufactured.
• Figures 2 and 3 show such a mold 10 for producing a generally elongate piece.
• This mold is hollow with a flat bottom 10a and a wall 10b of determined thickness and height corresponding to the thickness of the finished part. It comprises studs 11, 12 and 13 inside the cavity. According to the example of this figure the pads are at a height that allows them to come into contact with a lid 14 closing the mold. The height may, however, be less as shown in FIG.
• This insert here comprises two rectilinear portions between two half-circle portions.
• the straight portions may be parallel or not and the semicircular portions may be of the same diameter or not.
• the insert is made, without limitation, according to one of the methods taught by the patent FR 2886290. This includes the structure of the coated threads, their manufacture, the manufacture of a bonded sheet of coated threads, the joining of this web either on the metal support on which it is wound or at the lower layer ply, welding of son by laser or by contact between two electrodes. Insofar as the insert comprises at least one rectilinear portion it is more particularly made according to one of the methods presented in patent applications FR 07/05453 or FR 07/05454 of July 26, 2007 in the name of the applicant.
• the insert can be obtained from a plurality of coated wires each comprising a ceramic fiber coated with a metal sheath with a winding step around a part of revolution, a part of the winding being effected in one direction. straight.
• the insert forms a rectilinear segment, it can be obtained from an insert blank with a rectilinear portion which is compacted and then cut into straight segments.
• the insert is positioned inside the cavity being spaced apart from the walls of the mold.
• One way to hold the insert in the mold is to arrange it on a support 16 which, if necessary, is of width corresponding to that of the insert and over the entire length of the latter or on pawns distributed under the insert.
• This support is preferably in the same metal as the powder.
• the support may consist of a L-shaped section piece 16 'as shown in FIG. 4.
• the support is advantageously constituted by the mandrel on which the coated thread has been wound to constitute the insert as described in FR2886920.
• the mold is filled with metal powder 18.
• the metal may be a titanium alloy such as TA6V alloy or a nickel alloy such as the unknown 625 or a stainless steel. It is an alloy in a granulometric form suitable for use in powder metallurgy.
• the powder can be introduced into the mold in part before the introduction of the insert, with pre-compaction if necessary. Then the mold is filled.
• the lid 14 is placed on the mold thus filled and the cavity is evacuated. The enclosure is finally sealed tightly by welding.
• the mold thus prepared is placed in a hot isostatic compression chamber.
• the enclosure thus makes it possible to maintain the workpiece at a temperature of 1000 ° C. and a pressure of 1000 bars for several hours. Under these conditions the mold is deformed due to the volume reduction between 20 and 25% of both the insert and the powder.
• the powder is completely densified and no porosity remains. All the parts in contact are welded by soldering diffusion.
• the coated wires are welded together forming a matrix within which the ceramic fibers are contained.
• the metal constituting the matrix of the insert is the same as that constituting the powder. It may be distinct, however.
• the mold is then removed by selective acid or mechanical dissolution. If necessary, the workpiece is machined to obtain the desired shape. This method makes it possible to vary the production of the parts.
• the studs extend over the entire height of the mold cavity. A minimum of material was used.
• a piece 20, such as that represented in FIG. 9, is obtained with openings 21, 22, and 23 through-holes.
• the integrated insert 15 in the mass is visible by transparency.
• FIG. 9 shows an example of a piece that can thus be made using the invention. Its cost of production is reduced by about 30% compared to a technique implementing machining after hot compression.
• the pads 51, 52, 53 of the mold 50 extend only partially over the height of the mold cavity.
• a piece 50 ' is obtained with lightened parts 51' 52 '53' but no through opening as seen in FIG. 6.
• the insert is visible by transparency in the figure
• FIG. 7 In the example of Figure 7 is used a mold 70 and its associated cover 71 which have symmetrical pads 72, 73 relative to a median wall 74.
• the molding 70 'of Figure 8 is symmetrical.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)
• Powder Metallurgy (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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• 2007
  • 2007-12-28 FR FR0709173A patent/FR2925897B1/fr not_active Expired - Fee Related
• 2008
  • 2008-12-24 EP EP08867160A patent/EP2245204B1/de active Active
  • 2008-12-24 CN CN200880123123.7A patent/CN101918609B/zh active Active
  • 2008-12-24 WO PCT/EP2008/068292 patent/WO2009083571A1/fr active Application Filing
  • 2008-12-24 US US12/810,874 patent/US8557175B2/en active Active
  • 2008-12-24 CA CA2710455A patent/CA2710455C/fr not_active Expired - Fee Related
  • 2008-12-24 RU RU2010131478/02A patent/RU2492273C2/ru not_active IP Right Cessation
  • 2008-12-24 JP JP2010540141A patent/JP5657392B2/ja not_active Expired - Fee Related
  • 2008-12-24 ES ES08867160T patent/ES2388887T3/es active Active
  • 2008-12-24 BR BRPI0821414A patent/BRPI0821414A8/pt not_active IP Right Cessation
• 2010
  • 2010-06-24 IL IL206629A patent/IL206629A0/en unknown

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