US3713206A - Method for the manufacture of a composite refractory metallic element with porous coating - Google Patents

Method for the manufacture of a composite refractory metallic element with porous coating Download PDF

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Publication number
US3713206A
US3713206A US00044508A US3713206DA US3713206A US 3713206 A US3713206 A US 3713206A US 00044508 A US00044508 A US 00044508A US 3713206D A US3713206D A US 3713206DA US 3713206 A US3713206 A US 3713206A
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United States
Prior art keywords
coating
brazing
support
porous
porous coating
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Expired - Lifetime
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US00044508A
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English (en)
Inventor
P Galmiche
J Pelissier
R Spinat
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Office National dEtudes et de Recherches Aerospatiales ONERA
Safran Aircraft Engines SAS
Original Assignee
Office National dEtudes et de Recherches Aerospatiales ONERA
SNECMA SAS
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/28—Selecting particular materials; Particular measures relating thereto; Measures against erosion or corrosion
    • F01D5/288—Protective coatings for blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
    • B23K35/001—Interlayers, transition pieces for metallurgical bonding of workpieces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
    • F01D11/12—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator using a rubstrip, e.g. erodible. deformable or resiliently-biased part
    • F01D11/122—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator using a rubstrip, e.g. erodible. deformable or resiliently-biased part with erodable or abradable material

Definitions

  • the casing of a turboreactor is constituted of a refractory alloy based on nickel and includes an abradable porous metallic coating constituted by a nickel felt.
  • the coating is bonded by brazing to the casing by applying the coating on the casing by a pressure ring with a larger coefficient of expansion and by effecting the brazing in a fluorinated-hydrogenated atmosphere at a temperature in the region of the fusion temperature of the solder.
  • the assembly is then subjected to a chromization or chromaluminization treatment in a halogenated-hydrogenated atmosphere (free of fluorine) at a temperature of 800 to 1 100C.
  • the invention relates, on the one hand, to methods for the manufacture of composite refractory metallic elements comprising a porous metallic coating with communicating pores fixed on a compact refractory metallic support, and, on the other hand, to the corresponding composite refractory metallic elements.
  • a first feature of the invention relative to the methods of the type concerned and intended to ensure, in the refractory metallic element with a porous coating, the rigid bonding of the porous metallic coating and of the compact metallic support intended to receive the said coating, consists, in interposing between the said porous coating and the said compact support a filler metal brazing suited to the nature of these two materials and containing at least one metal of the group iron-cobalt-nickel (advantageously nickel), in then subjecting the composite element thus constituted to an application pressure causing compression of the brazing filler metal between the porous coating and the compact support, and finally in effecting the brazing operation proper in a partially gas-tight container, by subjecting the brazing, filler metal through the porous coating, to the action of a fluorinated atmosphere at a temperature close to the fusion temperature of the brazing filler metal so that the latter effectively wets the contact surfaces without in practice penetrating into the porous coating, this brazing operation being conducted in a hydrogenated atmosphere including herein its
  • a second feature of the invention relative to the improvement of a composite refractory metallic element of the type concerned of which the porous coating contains nickel, consists, once the porous coating is fastened to the compact support, especially by a brazing operation according to the first feature, in subjecting the abovesaid element to a treatment of chromization or of chroma-luminization utilizing a halogenated atmosphere free of fluorine (possibly iodine but preferably chlorine and/or bromine by reason of the particularly high vapor pressures at high temperatures of chlorides and bromides), the abovesaid treatment being effected during several hours to several tenths of hours at a temperature of 800 to 00C in a partially gas-tight container and arranged, from the beginning of the rise in temperature to the end of cooling, in an enclosure in which a hydrogenated atmosphere exists, due to which there is obtained, by reason of the application of chromium or of chromium and aluminum, an improvement of the characteristics in depth of the porous coating, of those of the
  • the compact support is constituted of stainless steel or of refractory alloy based on nickel or cobalt, and, on the other hand, the porous coating has a total porosity at least equal to 25 percent and contains an appreciable proportion of nickel and/or of cobalt and/or ofiron.
  • the utilization of the first feature enables the production in improved manner (increased resistance to tearing-off) of the desired bond between the porous coating and the compact support
  • the later utilization of the second feature enables the transformation in depth of the porous coating by chromization or chromaluminization by thus rendering it unoxidizable, of improving the behavior to oxidation and of raising the fusion point, henceof improving the refractory characteristics, of the brazing, and even of transforming the superficial layers of the compact support by softening of the constituent refractory material of the said layers.
  • casings with an abradable internal coating for stages of gas turbines which casings can be constituted by composite elements (envelope and inner coating) having, either the form of one-piece rings, or the form of sectors subsequently assembled together in an outer support.
  • FIG. 1 shows, in diagrammatic manner and in longitudinal section, a gas turbine casing element with abradable porous inner coating, and said element being constructed according to the invention
  • FIG. 2 shows, in diagrammatic manner and in transverse section, an assembly used for applying against one another the inner coating and the outer envelope of the abovesaid casing element during the process of the manufacture of the latter.
  • the envelope 1 is advantageously constituted of a refractory alloy based on nickel, on cobalt, or on chromium, and there may be mentioned, as refractory alloys of this type, those denoted by the trade names HASTELLOY X, MULTIMET, RENE 41, HS 25, TD. NICKEL, T.D. NICKEL-CHROME and ACIER 25-20.
  • the abradable porous metallic coating 2 it is preferably constituted by a nickel felt generally having the form of strips of a thickness of two to three millimeters and a porosity of about 80 percent, felts of this type being marketed by the American firm GENERAL ELECTRIC and by the French firm METAFRAM.
  • the fixing of the coating 2 on the inner wall of the envelope 1 is effected
  • a brazing filler metal layer 3 containing phosphorus and at least one metal of the group iron cobalt nickel which is preferably a nickel-based brazing,metal, for example a powdered brazing metal for example brazing by powder, known commercially by the name NICROBRAZ 50, based on nickel containing chromium (13 percent) and phosphorus percent), the latter brazing material having a fusion point of 890C and its positioning,.in the form of a thick layer of 50 to 250 microns, being done preferably from a suspension of the said brazing material in a lacquer or by deposition by a plasma torch,
  • the elements subjected to this brazing operation are arranged in partially gas-tight containers, at the bottom of which is placed a mixture of particles of chromium and of ammonium fluoride, exposed to a hydrogenated protective atmosphere during the rise in temperature, the treatment proper (several hours) and the cooling.
  • the assemblies obtained have a uniform pearly gray appearance and excellent resistance (distinctly greater than that of the porous coating considered alone) to tearing-off forces tending to separate the compact envelope 1 from the porous coating 2 free in depth of brazing material, these good results being obtained whatever the relative positions of the said coating with respect to the abovesaid envelope.
  • the initial porosity and thickness of the porous coating 2 are not appreciably affected by the brazing operation which has just been considered.
  • This subsequent treatment has the effect, on the one hand, of conferring on the porous coating 2, throughout its mass, i.e., on all the walls and its multiple communicating cells, an unoxidizable character, on the other hand, of reinforcing the behavior to oxidation of the brazing zone and of raising its fusion point, and, finally, on the other hand, of also improving the behavior to oxidation of the superficial layers of the subad jacent envelope to the abovesaid brazing zone.
  • the assembly constituted by the parts and the chromization charge is placed in partially gas-tight containers, which are then heated (for several hours between 850 and l000C, and preferably for eight hours in the neighborhood of 950C), then cooled, under a hydrogenated protective atmosphere.
  • halogenides of chromium having the best penetrating power in the case of the treatment of porous materials are the bromide and the chloride of chromium by reason of the particularly high vapor pressures at high temperature of these two halogenides.
  • halogenides of chromium are formed in situ on the chromization treatment from a reaction between chromium and the additional halogenated carrier, in this instance ammonium bromide and/or chloride which are added initially in amounts of the order of 1 to 2 percent by weight in the chromization charges.
  • additional halogenated carrier in this instance ammonium bromide and/or chloride which are added initially in amounts of the order of 1 to 2 percent by weight in the chromization charges.
  • Such a chromization treatment ensures a complete transformation of the porous nickel into stainless porous nickel-chromium of pearly gray appearance and, in addition, it improves the strength characteristics 'of the composite element and of the brazing zone. Moreover, the enrichment in chromium of the brazed zones increases appreciably the fusion temperature and the resistance to oxidation of the said zones.
  • the average content of chromium of the chromized porous nickel coatings reaches about 35 percent, i.e., the materials obtained have a chemical composition close to those of the best nickel-chromium refractory alloys.
  • the plasticity of the porous coating thus chromized is substantially increased, which enables possible envisaging of a later trueing of assemblies which have been subjected to deformations during the operation of bonding or of protection.
  • the chromization treatment could be followed by a selective homogenization and oxidation annealing, by heating for several hours towards 850 950C in an atmosphere of non-purified electrolytic hydrogen or of wet hydrogen, this complementary treatment giving rise to the formation of a very fine layer of pure chromium oxide on the surface of each grain of chromized nickel, such a layer substantially improving the behavior of the treated material relative to oxidation at high temperature.
  • the treatment of protection by chromaluminization which treatment is intended to transform the porous nickel into unoxidizable porous nickel-aluminum-chromium, it is preferably effected by having recourse, for the application of chromium and aluminum, to ultra-fine and homogeneous pre-alloyed powders, of which each grain is constituted by an alloy of chromium and aluminium, such powders enabling permanent assurance of saturation of the treatment atmosphere of halogenide carriers, which leads to a much accentuated penetrating power.
  • the composite elements to be treated are arranged in partially gas-tight containers in contact with an intimate mixture of pre-alloyed ultra-fine powder of chromium-aluminum and alumina supplemented with a bromine and/or chlorine halogenated carrier (especially ammonium bromide and/or chloride), the containers thus equipped being heated (for several hours between 850 and 1000C, and preferably for 8 hours in the region of 950C), then cooled, under a hydrogenated protective atmosphere.
  • a bromine and/or chlorine halogenated carrier especially ammonium bromide and/or chloride
  • porous nickel is completely transformed into unoxidizable porous nickel-aluminum-chromium of bluish gray appearance and the resistance characteristics of the composite elements and of the bonding zones are improved as in the case of simple chromization.
  • the average contents of aluminum and of chromium of the porous material tranformed by chromaluminization are respectively of the order of and 5 percent, and the average hardness of the transformed porous material is very much greater than that of the initial porous material.
  • the turbine casing element comprises, as shown in FIG. 2, on the one hand, an outer support ring 1 constituted of a refractory alloy based on nickel, and, on the other hand, an abradable porous metallic coating 2, also in the form of a ring, constituted essentially of nickel and having a porosity of the order of percent, a layer 3 of NICROBRAZ 50 solder being interposed between these two rings.
  • a clamping ring 4 constituted of a metal or alloy having a greater coefficient of expansion than that of the outer support ring l, the positioning of this clamping ring 4 being able to be effected by previously removing a sector 4a of this ring, by subjecting the said ring to constriction enabling its positioning in the ring of porous coating 2, and by re-establishing the continuity of the clamping ring 4 by the re-introduction of the sector 4a which then plays the role of a gap-filling insert.
  • constituent material of the clamping ring 4 there may be adopted, in the case where the constituent refractory alloy of the outer support ring 1 (for example based on nickel) has a coefficient of expansion at 20C less than l5.l0' a stainless steel Z I0 CNT 18 according to the French nomenclature (American nomenclature AISI 321), and in the case where the constituent refractory alloy of the outer support ring I (for example refractory steel Z6 NCT 25 according to the French nomenclature or A 286 according to the American nomenclature) has a coefficient of expansion at 20C greater than 15.10", a stainless steel Z 50 NMC 12 according to the French nomenclature corresponding to the American standard AMS 56-24.
  • the assembly is then placed in a muffle itself arranged in a hydrogen oven, the atmosphere of the muffle communicating with that of the oven and the abovesaid muffle containing, out of contact with the above said assembly, powder of chromium and of ammonium fluoride.
  • the brazing treatment is then effected at a temperature of 900 to 920C for several hours (4 to 5 hours for example).
  • This monobloc assembly is then subjected to a chromaluminization treatment effected in the same muffle and the same hydrogen furnace as the brazing treatment.
  • the monobloc element is immersed in a reactive mass filling the muffle, the said reactive mass being constituted by a mixture of pre-alloyed powder of chromium and aluminum, and alumina, supplemented with a slight quantity of ultra-fine powder of magnesothermic chromium and ammonium bromide, the ratio by weight of chromium and aluminum in this mixture being of the order of 10.
  • the assembly is then heated to a temperature of the order of 950C for about 12 hours, after which the onepiece element is maintained for about 2 hours at a temperature of the order of 800C to eliminate the halogenides which can remain in the porous coating ring 2.
  • the monobloc element thus obtained has then practically the same dimensions as following the brazing treatment and the chromaluminization treatment does not cause any internal stress in the abovesaid monobloc element.
  • Method for the manufacture of a composite refractory metallic element comprising a compact metallic support bearing a porous metallic coating, said method, to ensure the firm bonding of said porous coating to said support, including the successive steps of interposing between said porous coating and said compact support a layer of a brazing filler metal suited to the nature of said support and coating and containing at least one metal of the group iron, cobalt and nickel,
  • brazing operation including herein its initial phase of bringing up to temperature and final phase of cooling, being conducted in a hydrogenated atmosphere.
  • halogenated carrier is a member selected from the group consisting of a bromide, a chloride and a mixture of a bromide and a chloride.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
US00044508A 1969-06-10 1970-06-08 Method for the manufacture of a composite refractory metallic element with porous coating Expired - Lifetime US3713206A (en)

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FR6919210A FR2049448A5 (enrdf_load_stackoverflow) 1969-06-10 1969-06-10

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US (1) US3713206A (enrdf_load_stackoverflow)
CA (1) CA937107A (enrdf_load_stackoverflow)
CH (1) CH516370A (enrdf_load_stackoverflow)
DE (1) DE2028630C3 (enrdf_load_stackoverflow)
FR (1) FR2049448A5 (enrdf_load_stackoverflow)
GB (1) GB1298860A (enrdf_load_stackoverflow)
SE (1) SE365964B (enrdf_load_stackoverflow)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3807030A (en) * 1972-12-27 1974-04-30 Chrysler Corp Method of preparing oxidation resistant materials
US4081121A (en) * 1974-12-13 1978-03-28 C.E.R.C.A., Compagnie pour 1'Etude et la Realisation de Combustibles Atomiques Method of high temperature assembly
US4119262A (en) * 1977-07-05 1978-10-10 Ford Motor Company Method of joining metal, particularly aluminum or aluminum alloys, using bromine fluxing agent
US4965095A (en) * 1979-03-30 1990-10-23 Alloy Surfaces Company, Inc. Method for refurbishing used jet engine hot section airfoils
US5915193A (en) * 1995-05-18 1999-06-22 Tong; Qin-Yi Method for the cleaning and direct bonding of solids
US6416589B1 (en) 1999-02-18 2002-07-09 General Electric Company Carbon-enhanced fluoride ion cleaning
WO2003010419A1 (de) * 2001-07-23 2003-02-06 Alstom Technology Ltd Vorrichtung zur dichtspaltreduzierung zwischen bewegten und stationären komponenten innerhalb einer strömungsmaschine
WO2007065403A1 (de) * 2005-12-07 2007-06-14 Mtu Aero Engines Gmbh Verfahren zum herstellen eines einlaufbelags
WO2011015192A1 (de) * 2009-08-06 2011-02-10 Mtu Aero Engines Gmbh Reparatur von turbinenbauteilen und lotlegierung hierfür
US20110086163A1 (en) * 2009-10-13 2011-04-14 Walbar Inc. Method for producing a crack-free abradable coating with enhanced adhesion

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4155755A (en) * 1977-09-21 1979-05-22 Union Carbide Corporation Oxidation resistant porous abradable seal member for high temperature service
RU2558026C1 (ru) * 2014-03-03 2015-07-27 Федеральное государственное унитарное предприятие "Всероссийский научно-исследовательский институт авиационных материалов" (ФГУП "ВИАМ") Способ пайки пористого материала с подложкой

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2424878A (en) * 1944-10-28 1947-07-29 Reed Roller Bit Co Method of bonding a liner within a bore
US2561565A (en) * 1946-06-22 1951-07-24 United Aircraft Corp Process of fluxing and joining metal parts
US2585819A (en) * 1946-06-22 1952-02-12 United Aircraft Corp Process of joining metal parts
US2945295A (en) * 1957-12-20 1960-07-19 Westinghouse Electric Corp High temperature metallic joint
US3025596A (en) * 1959-06-26 1962-03-20 Combustion Eng Braze bonding of concentric tubes and shells and the like
US3417460A (en) * 1959-04-13 1968-12-24 Onera (Off Nat Aerospatiale) Methods of brazing

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2424878A (en) * 1944-10-28 1947-07-29 Reed Roller Bit Co Method of bonding a liner within a bore
US2561565A (en) * 1946-06-22 1951-07-24 United Aircraft Corp Process of fluxing and joining metal parts
US2585819A (en) * 1946-06-22 1952-02-12 United Aircraft Corp Process of joining metal parts
US2945295A (en) * 1957-12-20 1960-07-19 Westinghouse Electric Corp High temperature metallic joint
US3417460A (en) * 1959-04-13 1968-12-24 Onera (Off Nat Aerospatiale) Methods of brazing
US3025596A (en) * 1959-06-26 1962-03-20 Combustion Eng Braze bonding of concentric tubes and shells and the like

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3807030A (en) * 1972-12-27 1974-04-30 Chrysler Corp Method of preparing oxidation resistant materials
US4081121A (en) * 1974-12-13 1978-03-28 C.E.R.C.A., Compagnie pour 1'Etude et la Realisation de Combustibles Atomiques Method of high temperature assembly
US4119262A (en) * 1977-07-05 1978-10-10 Ford Motor Company Method of joining metal, particularly aluminum or aluminum alloys, using bromine fluxing agent
US4965095A (en) * 1979-03-30 1990-10-23 Alloy Surfaces Company, Inc. Method for refurbishing used jet engine hot section airfoils
US5915193A (en) * 1995-05-18 1999-06-22 Tong; Qin-Yi Method for the cleaning and direct bonding of solids
US6536135B2 (en) 1999-02-18 2003-03-25 General Electric Company Carbon-enhanced fluoride ion cleaning
US6416589B1 (en) 1999-02-18 2002-07-09 General Electric Company Carbon-enhanced fluoride ion cleaning
WO2003010419A1 (de) * 2001-07-23 2003-02-06 Alstom Technology Ltd Vorrichtung zur dichtspaltreduzierung zwischen bewegten und stationären komponenten innerhalb einer strömungsmaschine
WO2007065403A1 (de) * 2005-12-07 2007-06-14 Mtu Aero Engines Gmbh Verfahren zum herstellen eines einlaufbelags
JP2009518571A (ja) * 2005-12-07 2009-05-07 エムテーウー・アエロ・エンジンズ・ゲーエムベーハー なじみ層の製作方法
US20110020560A1 (en) * 2005-12-07 2011-01-27 Mtu Aero Engines Gmbh Method for Manufacturing a Run-In Coating
WO2011015192A1 (de) * 2009-08-06 2011-02-10 Mtu Aero Engines Gmbh Reparatur von turbinenbauteilen und lotlegierung hierfür
US8544716B2 (en) 2009-08-06 2013-10-01 Mtu Aero Engines Gmbh Repair of turbine components and solder alloy therefor
US20110086163A1 (en) * 2009-10-13 2011-04-14 Walbar Inc. Method for producing a crack-free abradable coating with enhanced adhesion

Also Published As

Publication number Publication date
DE2028630C3 (de) 1975-02-27
GB1298860A (en) 1972-12-06
DE2028630B2 (de) 1974-07-04
CA937107A (en) 1973-11-20
SE365964B (enrdf_load_stackoverflow) 1974-04-08
DE2028630A1 (de) 1970-12-17
FR2049448A5 (enrdf_load_stackoverflow) 1971-03-26
CH516370A (fr) 1971-12-15

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