Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
• • 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
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/10—Sintering only
  • B22F3/1003—Use of special medium during sintering, e.g. sintering aid
  • B22F3/1007—Atmosphere
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
  • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
• • 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
  • B22F2201/00—Treatment under specific atmosphere
  • B22F2201/02—Nitrogen
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12014—All metal or with adjacent metals having metal particles
  • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
  • Y10T428/12049—Nonmetal component
  • Y10T428/12056—Entirely inorganic
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12014—All metal or with adjacent metals having metal particles
  • Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
  • Y10T428/12146—Nonmetal particles in a component
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12014—All metal or with adjacent metals having metal particles
  • Y10T428/1216—Continuous interengaged phases of plural metals, or oriented fiber containing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12014—All metal or with adjacent metals having metal particles
  • Y10T428/1216—Continuous interengaged phases of plural metals, or oriented fiber containing
  • Y10T428/12167—Nonmetal containing

Definitions

• the present invention relates to a high-tenacity composite material containing an oxide-based reinforcing phase, and to a method of manufacturing the same.
• Ceramic-metallic composite materials can be used both as structural materials (engine parts, parts for aeronautics and the space industry) and as functional materials (cutting, drilling, drilling tools) .
• the aim is to associate the inherent mechanical properties of ceramic, such as hardness, wear resistance and a high elastic modulus, with those of a metal, such as toughness and resistance to mechanical and thermal shock. .
• Al2O3 aluminum oxide or alumina
• Al2O3 aluminum oxide or alumina
• the toughness and impact resistance of polycrystalline Al2O3 are very low.
• ceramics based on alumina are often added, for example, other ceramics such as ZrO2 and Y2O3 or carbides such as TiC.
• the toughness of metals is never reached and ceramic-metallic composites.
• the metals of the group Fe, Ni, Co, also known as ferrous metals are advantageous for applications at high temperature, because their melting point is situated at temperatures well above those reached in most industrial processes and yet easily obtainable during manufacture.
• the alloys of ferrous metals have excellent resistance to oxidation.
• Ferrous metals form a pseudo-eutectic lower than their melting point in the presence of carbides and carbonitrides such as TiC, TaC, WC, TiCN. These carbides and carbonitrides in combination with ferrous metals (mainly Ni and Co) are the basis of the vast majority of cermets currently produced.
• cermets targets increasingly high temperatures, which leads to problems of resistance to oxidation, resistance to creep and decohesion of interfaces.
• the introduction of a strengthening phase based on aluminum oxide could give cermets better temperature resistance thanks to the chemical resistance of Al2O3 and its refractory properties.
• the formation of intermediate oxides weakens the interfaces between the alumina and the metal.
• the poor wetting of ferrous metals towards the alumina makes it impossible to produce such cermets by sintering.
• the object of this invention therefore consists in providing a composite material having a high toughness and the refractory properties which are specific to ceramic, by forming around the ceramic oxide phase an interfacial layer guaranteeing good wettability and good toughness of the interface.
• the metal-ceramic material which is the subject of the invention and which aims to achieve the above-mentioned aim comprises a ceramic phase with particles of alumina or of a solid solution based on alumina, a refractory phase comprising nitride and / or titanium carbonitride and a metallic binder phase based on Ni, Co and / or Fe, the interface between the particles of alumina or of solid alumina solution and the metallic matrix being rich in nitrogen and titanium or in compounds of these.
• the interface mentioned above is generally formed by a continuous layer rich in TiN around the particles of alumina or of solid solution of alumina favoring a good wettability of the metallic matrix, and which can contain aluminum, under the form of compounds with titanium, nitrogen and / or a metal of the metallic phase, near this metallic matrix.
• the alumina can be in the form of powder, the grains of which have a diameter of 0.1 to 50 ⁇ m, preferably of 0.5 to 10 ⁇ m, or of monocrystalline plates whose form factor varies between 5 and 20 and the diameter between 5 and 50 ⁇ m, or even whiskers or filaments.
• the volume content of the ceramic phase can be between 10 and 80%, preferably between 20 and 50%, that of the refractory phase between 10 and 70% and that of the metal matrix between 3 and 50%.
• the content of the ceramic phase is between 5 and 30% vol., That of the refractory phase between 35 and 65% vol. and that of the metal matrix between 5 and 25% vol.
• the ceramic metal material may also contain as another main ingredient titanium carbide in addition to carbonitride or titanium nitride, or a mixture of the three.
• the metal matrix may contain additional dissolved ingredients, such as metals such as Sc, Y, Ti, Zr, Hf, V, Nb, Cr, Re, Ru, Al, C and N, between 0.1 and 5 % flight. and the refractory phase of carbides of Mo, W, V Hf, Nb, Cr, Ta, or nitrides such as AlN, TaN, ZrN and BN, between 0.5 and 15% vol.
• metals such as Sc, Y, Ti, Zr, Hf, V, Nb, Cr, Re, Ru, Al, C and N, between 0.1 and 5 % flight.
• the refractory phase of carbides of Mo, W, V Hf, Nb, Cr, Ta, or nitrides such as AlN, TaN, ZrN and BN, between 0.5 and 15% vol.
• the ceramic phase can also contain other oxides, such as ZrO2 or Y203 or a mixture of these oxides.
• another object of the present invention consists in a process for manufacturing the ceramic-metallic composite material defined above, which comprises sintering the constituent elements in a non-oxidizing nitrogen atmosphere, at a temperature of 1300 to 1600 °. C, preferably from 1450 to 1500 ° C, and at a pressure of 1 to 2000 atm, preferably from 1 to 200 atm. It can be combined with hot pressing or with isostatic hot pressing.
• one of the main characteristics of the present invention consists in forming an intermediate layer on the surface of the ceramic phase. having affinities with the matrix, this layer being rich in nitrogen and titanium. It is well known that metals wet ceramics by forming chemical bonds. When the wetting is poor, the reaction between the metal and the atoms on the surface of the ceramic is not thermodynamically favorable. The presence of a reactive layer can thus provide the motive force necessary for the wetting reaction.
• the interface layer is maintained during sintering by adding nitrogen and a metallic element, preferably titanium, in solution in the matrix. There is thus the deposition of a nitride.
• the energy supplied by this reaction during sintering increases the wetting and the epitaxial precipitation of the nitride guarantees the homogeneity and the tenacity of the interface.
• the interface layer can be obtained by PVD or CVD deposition, in which case it has a thickness between 0.5 and 5 ⁇ m, or by nitriding of Al2O3 before sintering or during sintering in a nitrogen atmosphere, in which case it has a thickness between 10 and 1000 nm. Nitriding can be helped by the addition of carbon which allows the reduction of alumina.
• the manufacture of the composite material generally comprises first of all the mixing of the powders of the binding phase. More particularly, a slip is first prepared by mixing the binding phase in the form of powders with a liquid organic product such as polyethylene glycol. The slip is mixed for 12 h in a ball mill, then degassed to adjust the viscosity. The oxide ceramic is added to this mixture. A light grinding of the total mass is necessary to obtain good homogeneity.
• We then pass to the shaping which can be carried out by dry pressing, filter pressing, slip casting, extrusion or injection. The shaped parts are then sintered. Pre-sintering at a temperature between 300 and 700 ° C may be necessary to completely release the organic binder. Sintering is carried out at a temperature between 1300 and 1600 ° C, for 1-4 hours, under nitrogen at a pressure between 5.104 and 2.108 Pa.
• the thickness of the interface between the alumina particles and the metal matrix is 100 to 10,000 Angstroms when it is obtained by prior surface nitriding of said particles. On the other hand, this thickness may be from 0.1 to 1 ⁇ m if the interface is obtained after chemical deposition of a titanium compound on the alumina particles, and from 0.05 to 5 ⁇ m in the case where this interface is obtained for sintering.
• the powders of the composite matrix were previously mixed with 2% polyethylene glycol and ground for 12 h in a ball mill.
• the Al2O3 plates are added to the slip and the whole is mixed in a ball mill for 2 hours.
• This mixture is then dried in air at 50 ° C., deagglomerated in a ball mixer and dry press with a pressure of 140 MPa. Sintering is then carried out at 1500 ° C. for 1 hour under a nitrogen atmosphere.
• Al2O3 platelets suspended in hexane are introduced into a laboratory autoclave.
• the Al2O3 platelets are dispersed in hexane for 15 minutes with an ultrasonic probe.
• a 10% solution of TiCl4 in hexane is introduced, and simultaneously a stream of ammonia is passed through for 10 minutes.
• the TiCl4.NH3 complex is thus precipitated on the platelets.
• the powders obtained are then dried under vacuum. After this treatment, the powders are oxidized in an oven in air at 900 ° C. for 1 h.
• the powders obtained are mixed at equal weight with powdered graphite powder and heated to 1150 ° C. under a flow of nitrogen. We stay at this temperature for 4 h.
• a TiN layer of less than about 1 ⁇ m was thus obtained on the surface of the Al203 powders according to the reaction: 4) 2Ti02 + 4C + N2 -> 2TiN + 4CO ⁇
• microstructure of the composite materials according to the invention shows the aluminum oxide particles uniformly dispersed in a phase consisting of metal islands in a ceramic skeleton of titanium carbonitride.
• the metal also surrounds the oxide particles.
• the interface between the metal and the oxide which has a thickness between 0.03 and 0.1 ⁇ m consists mainly of titanium nitride.
• the present invention makes it possible to appreciably improve the toughness of cermets, while keeping a high hardness, by the introduction of alumina particles, this provided that the alumina is treated before or during sintering so as to promote the formation of an interface rich in nitrogen and titanium. It can also be noted that pressure sintering (Sample 4) makes it possible to obtain excellent mechanical properties with a significant reduction in the duration of said sintering.

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• 1993
  • 1993-11-01 CH CH03288/93A patent/CH686888A5/fr not_active IP Right Cessation
• 1994
  • 1994-10-25 EP EP94116793A patent/EP0651067B1/de not_active Expired - Lifetime
  • 1994-10-25 AT AT94116793T patent/ATE191015T1/de not_active IP Right Cessation
  • 1994-10-25 DE DE69423565T patent/DE69423565D1/de not_active Expired - Lifetime
  • 1994-10-28 JP JP6287242A patent/JPH07188803A/ja active Pending
  • 1994-11-01 US US08/332,056 patent/US5682595A/en not_active Expired - Fee Related

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