WO1984002483A1 - Pieces en poudre metallique a surface modifiee et leurs procedes de fabrication - Google Patents

Pieces en poudre metallique a surface modifiee et leurs procedes de fabrication Download PDF

Info

Publication number
WO1984002483A1
WO1984002483A1 PCT/US1983/002059 US8302059W WO8402483A1 WO 1984002483 A1 WO1984002483 A1 WO 1984002483A1 US 8302059 W US8302059 W US 8302059W WO 8402483 A1 WO8402483 A1 WO 8402483A1
Authority
WO
WIPO (PCT)
Prior art keywords
metal
article
sintered
coating
surface layer
Prior art date
Application number
PCT/US1983/002059
Other languages
English (en)
Inventor
Mark F Mosser
Bruce G Mcmordie
Original Assignee
Sermatech Int Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sermatech Int Inc filed Critical Sermatech Int Inc
Priority to AU24395/84A priority Critical patent/AU2439584A/en
Publication of WO1984002483A1 publication Critical patent/WO1984002483A1/fr

Links

Classifications

    • 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
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • 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
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/02—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers

Definitions

  • This invention relates generally to powder metal (P/M) parts, more specifically to a part consisting of a powder metal core coated with a sintered metal surface layer possessing different properties (i.e. density, hardness) and/or composition than that core.
  • the invention also relates to methods of forming such parts. These parts combine the advantage of powder metal technology with those of machined or cast parts.
  • the products of the invention make an important contribution to the field of powder metallurgy.
  • metal particles e.g. powders
  • This technique known as pressing and sintering, produces a strong metal part and utilizes less time, raw material and energy than do conventional casting and machining processes.
  • Powder metallurgy is well known in the art.
  • Powder metallurgy F.V. Lenel, Metal Powder Industries Federation (1980); Handbook of Powder Metallurgy, Henry H. Hausner, Chemical Publishing Co. (1973); Technology of Metal Powders, Recent Developments 1980, Edited by L.H. Yaverbaum, Noyes Data Corp. (1980); Powder Metallurgy Processing, New Techniques and Analyses, Edited by H.A. Kuhn and A. Lawley, Academic Press (1978); Particulate Science and Technology, J.K. Beddow, Chemical Publishing Co. (1980); Source Book on Powder Metallurgy, Samuel Bradbury, American Society for Metals (1979); Sintering, M.B. Waldron and B.L. Daniell,
  • P/M parts contain some degree of porosity.
  • the metal powders that are the raw material for P/M parts never liquify during sintering and the voids which exist between the deformed particles in the compacted shape are retained in the finished product.
  • the resulting unique structure of rigid metal encompassing a network of interconnected voids renders P/M products ideal for applications where parts must be permeable to fluids, such as filters or self-lubricating bearings.
  • the porosity inherent in the pressed and sintered product makes these parts more susceptible to corrosion damage than are their cast or machined counterparts. Owing to the presence of the open network of voids, internal as well as external, surfaces are exposed to the debilitating effects of the environment. These extensive surface areas also render these parts vulnerable to deterioration by chemicals.
  • P/M parts exhibit lower surface hardness than do cast or machined items of identical composition, because some proportion of the P/M surface is open space. Furthermore, it is extremely difficult to produce a continuous metal plating or to achieve a uniform finish of any kind on the porous surface of a pressed and sintered part.
  • U.S. Patent No. 3,320,058 to Krock et al relates to tungsten structures having high density outer surfaces and a core of controlled porosity. Such “armoured” structures are achieved by dusting the surfaces of compacted tungsten powders with nickel particles before sintering at 1100°C to 1400°C. In this temperature range, the nickel diffuses into the compacted core along the boundaries of the tungsten particles. The nickel activates sintering of the tungsten by lowering activation energy for diffusion. Hence the inwardly diffusing nickel leads to complete densification of the surface of the tungsten compact.
  • the resultant tungsten structures are disclosed to be useful as ion emitters, permeable membranes, conduit means for fluids such as gases and liquids, and fluid filters. They are proposed as replacements for fibrous materials, such as paper filters and others.
  • U.S. Patent No. 2,644,656 to Jacquier deals with porous plates for alkaline storage batteries.
  • the plates are constituted of porous particles of nickel or of nickel-coated iron subsequently sintered or fused. Particles are fused together to form the consolidated or integral porous mass.
  • the nickel coating on the iron particles is fairly considerable in that it exceeds 20% of the total amount of nickel and iron.
  • U.S. Patent No. 3,682,062 to Jackson discloses a sintered ferrous metal length with chromium penetrating its thickness .
  • U.S. Patent No. 3,989,558 to Maynard et al discloses carbides sintered with cobalt, like tungsten carbide coated with osmium and ruthenium. The coating is made to diffuse into the cobalt.
  • the invention described herein provides a means to modify the surface of a pressed and sintered part without use of the extensive processing or the high temperature equipment described above.
  • Surface modification is -instead accomplished by sintering onto the surface of the part, a metal layer that is distinct from the body of the part in composition and/or structure.
  • This unique metallic surface layer is produced by coating either an unsintered ("green") or sintered P/M part with a slurry of metal pigments in a high temperature binder, and then sintering the coated part in accordance with typical industry practice. During sintering, the metal pigments in the coating fuse to form a distinct metal layer, most preferably 10 to 50 microns thick, on the surface of the sintered P/M part.
  • the composition and structure of this layer are controlled by the composition of the coating slurry and, to a lesser degree, by sintering time and temperature.
  • the invention provides powder metal parts which comprise a modified surface layer.
  • the surface layer has characteristics which are different from those of the core in one or more respects.
  • the modified surface may have different
  • OMPI hardness characteristics typically increased hardness
  • different resistance to exposure to chemicals different porosity, and other properties as will become apparent from the detailed description of the invention.
  • the invention provides new metal parts not known heretofore.
  • the metal particles in the coating may be as large as 150 microns; however, it is most preferable that the size of the powders not exceed 20 microns. Fine particles will enable the coating liquid to "bridge" surface voids ( Figure 1), forming a continuous layer or skin on the porous surface. Use of such powders also assures that any porosity retained in this continuous coating layer after sintering will be orders of magnitude smaller than that in the body of the P/M part which is formed from metal particles averaging 50 to 100 microns in diameter. Use of coarse particles or of particles that are themselves porous produces a sintered coating possessing a greater proportion of porosity than that of the powder metal substrate.
  • coating pigments not be limited to spherical powders. Flake and acicular powders also produce uniquely dense metal skins on the P/M part. Irregardless of the morphology of the pigment chosen for the coating, its composition is such that during sintering a continuous skin forms on the surface, and interior regions of the P/M part remain substantially or totally free of the sintered metal particles which form that coating.
  • the formation of a continuous sintered skin upon the outer surface of the part is accomplished by formulating the liquid coating to include any of a class of metal and alloy pigments referred to hereafter as rapidly sintering materials.
  • These basic building blocks of the coating of this invention are those elemental and alloy powders which are known to fuse and coalesce without melting, at the temperature at which the coated part is to be sintered.
  • the rapidly sintering component provides the physical structure or cohesiveness of the sintered coating.
  • the pigmentation of the coating need not be limited to these rapidly sintering pigments, though some must always be present. In fact, as they must be present only in sufficient quantity to provide the skeletal structure for the coating, there are cases, described below, in which the proportion of rapidly sintering pigments is only 5% of the total weight of pigmentation.
  • the exact metals and alloys constituting the set of rapidly sintering materials cannot be generally defined. Instead each is determined by the range of sintering temperatures at which the coating is to be used. For example, iron, nickel, cobalt, and their alloys sinter rapidly at temperatures above about 1050°C; therefore, these metals are the building block components of sinterable coatings for iron and steel (ferrous) P/M parts which are typically sintered between 1100°C and 1300°C. These same metals are not indispensable in coatings of the invention for use on brass or bronze P/M parts because these parts are sintered below about 900 C. Conversely, copper, which does not qualify as a rapidly sintering component for use on ferrous parts because it melts at 1080°C, qualifies as a rapidly sintering metal for use on brass and bronze substrates.
  • pigments can be used, in varying proportions in conjunction with the basic rapidly sintering ones, to produce a sintered skin possessing the desired properties.
  • Pigments hich are liquids at the sintering temperature may be added to the coating to increase the sintering rate of the other
  • pigments as well as the density of the product.
  • proportion of lower melting metals it is preferable to limit the proportion of lower melting metals to less than about 20% of the total weight of pigment to prevent the liquid metal from being totally absorbed into the body of the part during sintering.
  • High melting elements or alloys which would not react (sinter) with one another at typical sintering temperatures can nevertheless be used in coatings which also contain rapidly sintering metals such as those described above.
  • Even refractory metals (e.g. tungsten) and metal compounds (e.g. silicon carbides) can be incorporated as long as there is a sufficient quantity of rapidly sintering metal in the slurry to bind the unreactive particles to the substrate and each other after sintering.
  • One skilled in the art has no difficulty determining the optimum amounts of metals required to produce a coating possessing the desired properties.
  • any metal which undergoes or causes exothermic or stoichiometric reactions with either the base metal of the P/M part or another metal in the coating should be avoided inasmuch as such a reaction will interfere with sintering.
  • the structure and properties of the finished metal part can be varied considerably.
  • the particular elements in the coating slurry will determine the structure and properties of the finished product.
  • coatings containing nickel or stainless steel will produce sintered films with good corrosion resistance. The optimum performance will be achieved when the coatings contain 60 to 100% by weight of those metals.
  • the surface porosity of ferrous parts will be decreased or eliminated by coatings containing copper pigments because these pigments will be liquid at the sintering temperature of the ferrous parts.
  • the amount of low melting pigment i.e. copper, tin, etc.
  • the porosity of the ferrous P/M surface could also be increased if so desired by sintering to it a coating containing between 60 and 95% sponge iron powder.
  • Coatings of the invention which contain in addition hard metals such as chromium, or interstitial hardening elements, such' as carbon, will increase the superficial hardness of iron P/M parts, and those blending tungsten carbide or boron nitride with iron or nickel will produce durable, wear resistant surfaces.
  • These hard facing and wear resistant sintered coatings can contain as much as 95% by weight of the hard species (e.g. silicon carbide).
  • the metal particles which comprise the coating are applied to the part in a liquid binder. While any binder known in the art may be used, certain considerations should be taken into account in the selection of the preferred binders for use in the invention.
  • the binder not only facilitates applications of the chosen metal pigments to the P/M parts by spraying, brush or dip techniques, but also holds the metal pigments to the part surface as the temperature increases toward that of sintering.
  • the binder preferably should not impede or hinder diffusion between particles in the coating and those constituting the P/M compact.
  • the binder should evaporate at high temperatures or at least generate loosely adhering residues that can be easily removed from the sintered part.
  • the binder be such as to allow a high concentration of pigment in the cured film, most preferably 75% or more by volume.
  • binders which has been proven especially suitable is comprised of phosphate anions and chromate (or dichro ate) and/or molybdate anions.
  • phosphate anions and chromate (or dichro ate) and/or molybdate anions.
  • chromate or dichro ate
  • molybdate anions A variety of such solutions is known for treatment of metal surfaces.
  • Kirk and Othmer Encyclopedia of Chemical Technology, 2nd ed., Vol. 18, Interscience Publishers, John Wiley & Sons, Inc., 1969 (pages 292-303) describes phosphate and chromate coatings.
  • the United States patent literature describes coating solutions or dispersions for protective coating of metals, which compositions are suitable for supplying the metal particles to the porous part. Such compositions are disclosed by Allen (No. 3,248,251); Braumbaugh (No. 3,869,293); Collins (No.
  • a greater latitude is provided in the type of phosphate compositions which can be used with the specified metal additives.
  • Allen patent U.S. Patent No. 3,248,251
  • the Allen patent also discloses supplying a metal ion, as by way of a metal salt like a metal oxide, hydroxide or carbonate. (See, for instance, column 7.) In accordance with this invention such addition is optional.
  • the pH of the aqueous binder used herein is preferably but not necessarily in the range of about 1.0 to about 3.0.
  • binders is silica-containing organic and inorganic liquids, especially water-soluble alkali silicates, like potassium and sodium silicate. Also included are those liquids which generate silicates, such as alkyl (e.g. ethyl) silicates. It is preferable that those having low rather than high alkalinity be used, e.g. those having a high SiO ⁇ /M-O mole ratio.
  • Other useful binders include synthetic organic binders such as silicones and phenolic resins and inorganic glasses such as borates and other frits.
  • Coatings constituted of a mixture of metal pigments in a binder as described above are particularly well suited to be applied to commercially produced P/M parts.
  • the P/M part is constituted, as is known, of a metal which comprises iron, steel, nickel, cobalt, copper, aluminum, refractory oxides, precious metals and alloys thereof.
  • the compositions and properties of these substrate materials are described in the Metal Powder Industries Federation Specification No. 35.
  • the Specification also prescribes the sintering time and temperature required to achieve the desired property for a particular composition. Said Specification is incorporated herein by reference.
  • metal powders are first compacted into the desired shape of the part to be formed.
  • the structure of the unsintered part is illustrated in Plate I.
  • the compact can be sintered before applying the coating, in which case a second sintering operation is employed after applying the coating to form the fused, impervious or porous coating. It is also quite satisfactory to apply the coating to the compact when it is in a "green" (unsintered) state, in which case only a single sintering operation needs to be employed, this taking place after the coating is applied. If an iron P/M part is to be infiltrated with copper particles it is by far preferable to sinter the compact prior to applying the coating. Otherwise, it is optional whether the compact is sintered prior to or after applying the coating.
  • the liquid coating After applying the liquid coating to the part, it is dried and cured into a substantially water-insoluble film most preferably 15 to 100 microns thick with the particulate metal particles of the coating filling or bridging voids on the surface of the P/M core.
  • the structure of the coated compact is illustrated in Plate II.
  • the coated part is then placed into a sintering furnace where it is heated in a vacuum or a reducing atmosphere, usually consisting of nitrogen, hydrogen as well as carbon monoxide, carbon dioxide and methane or propane, to a temperature sufficient to fuse the coarse metal powders in the compact to one another.
  • a vacuum or a reducing atmosphere usually consisting of nitrogen, hydrogen as well as carbon monoxide, carbon dioxide and methane or propane, to a temperature sufficient to fuse the coarse metal powders in the compact to one another.
  • the fine metal particulate in the coating is sintering into a continuous mass as well as alloying itself with the metal in the compacted shape.
  • any binder residues are removed from the surface by mechanical finishing techniques.
  • the structure of the sintered coating and the sintered part is shown in Plate III.
  • Nickel powder was dispersed in a chromate/phosphate binder of the following composition: 100.0 gm water
  • the nickel/chromate/phosphate slurry was sprayed onto a green compact of atomized iron and copper powders.
  • the structure of this small disc which had been pressed at 30 tons/in to a green density of about 6.6 gm/cc, is shown in Figure 2.
  • the compact was sintered in a vacuum at 1121°C for one half hour.
  • the result was a sintered metal P/M disc with a sintered nickel surface.
  • Figure 3 shows the sintered iron disc with the sintered nickel coating.
  • Example 2 Three coats of the slurry described in Example 1 were sprayed onto a P/M spur gear which had been pressed and sintered from a blend of iron (95%), nickel (2%), copper (2%) and carbon (1%) powders. Each layer of the coating was cured at 343 C for one half hour. Figure 4 shows the cured coating on the surface of the gear. The coating was about 60 microns thick.
  • the coated gears were heated to 1121°C in a vacuum, held for one half hour at that temperature and then rapidly cooled by quenching in argon gas. At this temperature, the nickel particles in the coating sintered to form a nickel-rich layer on the surface of the gear.
  • Figure 5 shows the sintered coating on the porous part. The sintered coating was about 20 microns thick.
  • Nickel powder was dispersed in a silicate binder of the following composition:
  • OMPI This coating was misted onto a steel P/M gear, identical to that used in Examples 2 and 3, to form a thick, loosely packed coating layer.
  • Potassium silicate binders cure at room temperature.
  • Figure 7 shows a steel P/M gear coated with nickel. The coated part was allowed to sit at ambient temperature for several days (4 days) till cured. It was then sintered in a vacuum at 1121 C for one half hour. At this temperature, the nickel powder in the coating sintered to form a porous nickel "sponge" surface layer.
  • Figure 8 shows the sintered nickel/silicate coating on the steel P/M part.
  • the sintered coating is very compressible and is useful as a corrosion resistant reservoir for liquids, e.g. lubricants, resins, coolants, etc.
  • This coated part may be useful in applications requiring strong, dense parts with lubricated surfaces such as gears or load bearing bushings.
  • a sodium silicate solution such as PQ "G” silicate dissolved in water (18 gm/82 gm water) is a suitable substitute for Kasil #1.
  • nickel powder was substituted by a_ mixture of 80% nickel and 10% cobalt, powders by weight, which formed an alloy coating on the iron part. Excellent resistance to salt spray was observed.
  • Example 1 through 4 the nickel powder in the coating slurry was replaced by 316L stainless steel powder which had been screened less than 325 mesh.
  • the sintered coating was more porous than that produced using nickel powders; however, the salt corrosion resistance of the coated parts was markedly better than than of bare iron P/M parts.
  • a mixture of nickel powder and tungsten carbide powder was dispersed in a chromate/phosphate binder of the following composition:
  • This coating was also sprayed onto a Fe-Ni-Cu-C P/M spur gear and cured at 343°C for one half hour.
  • Figure 9 shows the cured coating on a spur gear.
  • the coated gear was then heated in a vacuum at 1121 C for one half hour.
  • the resultant sintered coating consisted of hard tungsten carbide particles dispersed in a soft nickel matrix of limited or low porosity.
  • Figure 10 shows the structure of the sintered coating.
  • Example 7 The binder of Example 7 was constituted without surfactant and without fumed silica. Because this binder was less viscous, the heavy particles settled from suspension quickly. Nevertheless, by constantly agitating the solution, a coating could be sprayed onto the P/M gear. A coating of the characteristics as described in Example 7 was obtained after sintering.
  • Iron powder was dispersed in a chromate/phosphate binder of the following composition:
  • This coating was sprayed onto a sintered iron P/M disc with a density of only 5.8 gm/cc.
  • the coated disc was resintered at 1121 C for one half hour in a vacuum.
  • the sintered coating was porous; however, the porosity was much smaller than that of the disc core.
  • Figure 11 shows an iron disc that had been coated and resintered.
  • the discs were then clamped in a device in which one side was pressurized and the time measured until sufficient air leaked through the disc to equalize the pressure on the two sides of the disc.
  • the iron disc contained so much large and interconnected porosity that the pressure equalized within 3 seconds.
  • the sintered iron coating did not completely seal the part; however, it did take 30 seconds for the pressure to equalize on the coated disc. This further establishes the differences in porosity (in size and number of pores) between the coating (sintered and alloyed onto the surface of the part) and that of the part itself.
  • the coating described in the above example was sprayed onto an unsintered compact of nickel powder.
  • the density of the compact was 7.2 gm/cc.
  • the part was vacuum sintered at 1200 C, a uniform skin formed on the surface.
  • the etching behavior of this skin demonstrated that it was almost pure iron.
  • the invention described herein provides a means to economically produce a metal part from individual metal powders that possesses surface properties similar to or superior to that of the cast or machined item of the same base metal composition. It is contemplated that many items routinely produced by P/M technology (i.e. gears, bearings, levers, cams, actuators, etc.) can now be produced with harder, more wear resistant, more corrosion resistant surfaces than previously possible and that some totally new products could be also produced.
  • the invention provides a means to fabricate clad sheet steel directly from iron and graphite powders. It is well known that iron and graphite powders can be roll compacted into a continuous green strip which can be fed directly into a sintering furnace to produce a continuous P/M sheet steel product. However, the economic savings of this technique over established billet hot and cold rolling technologies are so small as to make the process impractical. If, however, the green strip were sprayed with a coating containing stainless steel or nickel pigments in accordance with this invention, the sintered product is a stainless steel alloy- or nickel-clad carbon steel superior in corrosion resistance to conventional rolled product and yet just as ductile and economical to produce.
  • sinterable coatings need not be limited to P/M products.
  • the concept of the invention is workable on any metal product (cast, wrought or P/M) that can survive exposure to the temperatures required to sinter the coating. - 18 -
  • Example 1 produced a very dense nickel film on a 1010 steel panel when sintered at 1121°C for one half hour.
  • the resultant coating is shown in Figure 12.

Abstract

Une pièce métallique frittée possède un noyau comprimé et fritté. La pièce est revêtue d'une couche superficielle de métal fritté. Cette couche possède une propriété différente de celle de la pièce métallique. Les régions intérieures du noyau sont exemptes du métal constituant le revêtement. Des procédés de fabrication de telles pièces sont également décrits.
PCT/US1983/002059 1982-12-29 1983-12-28 Pieces en poudre metallique a surface modifiee et leurs procedes de fabrication WO1984002483A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU24395/84A AU2439584A (en) 1982-12-29 1983-12-28 Surface modified powder metal parts and methods for making same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US45447382A 1982-12-29 1982-12-29

Publications (1)

Publication Number Publication Date
WO1984002483A1 true WO1984002483A1 (fr) 1984-07-05

Family

ID=23804740

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1983/002059 WO1984002483A1 (fr) 1982-12-29 1983-12-28 Pieces en poudre metallique a surface modifiee et leurs procedes de fabrication

Country Status (4)

Country Link
EP (1) EP0131045A4 (fr)
JP (1) JPS60500376A (fr)
CA (1) CA1216197A (fr)
WO (1) WO1984002483A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1985005352A1 (fr) * 1984-05-24 1985-12-05 Höganäs Ab Corps fritte heterogene
EP0181409A1 (fr) * 1984-04-24 1986-05-21 Institut Organicheskogo Sinteza Akademii Nauk Latviiskoi Ssr Derives de 15(r+s)-fluor-11,15-didesoxyprostaglandine e 1?
FR2613008A1 (fr) * 1987-03-23 1988-09-30 Dana Corp Couvercle pour frein d'embrayage, son procede de fabrication et frein d'embrayage associe
US4919243A (en) * 1987-03-23 1990-04-24 Dana Corporation Clutch brake having segmented cover surfaces
GB2324537A (en) * 1997-04-25 1998-10-28 Hitachi Powdered Metals Easily machined iron based sintered alloy
WO2015112365A1 (fr) * 2014-01-24 2015-07-30 United Technologies Corporation Amélioration de poudre pour fabrication additive

Family Cites Families (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2245609A (en) * 1940-03-07 1941-06-17 American Chem Paint Co Metal finishing process
US2512455A (en) * 1945-12-31 1950-06-20 Metal Hydrides Inc Copper-titanium coating and bonding process
US2626221A (en) * 1948-02-26 1953-01-20 Reed Roller Bit Co Process of applying hard surfacing material to metal bodies
US2763921A (en) * 1952-01-24 1956-09-25 Thompson Prod Inc Corrosion and impact resistant article and method of making same
US2885301A (en) * 1956-08-02 1959-05-05 Metal Diffusions Inc Chromizing coating
US3053925A (en) * 1959-01-22 1962-09-11 Electric Storage Battery Co Porous sintered plate
US3081146A (en) * 1959-02-27 1963-03-12 Nalco Chemical Co Inhibition of corrosion of metal surfaces in contact with corrosive aqueous media
US3248251A (en) * 1963-06-28 1966-04-26 Teleflex Inc Inorganic coating and bonding composition
US3248250A (en) * 1963-06-28 1966-04-26 Teleflex Inc Coating and bonding composition
US3248249A (en) * 1963-06-28 1966-04-26 Telefiex Inc Inorganic coating and bonding composition
US3320058A (en) * 1966-02-16 1967-05-16 Mallory & Co Inc P R Method of producing a porous tungsten structure with an impervious skin
US3475161A (en) * 1967-03-14 1969-10-28 Howmet Corp Method of forming cemented carbide coatings on metal surfaces by employing volatile,organic liquid solvents and organic binders
US3577226A (en) * 1967-06-30 1971-05-04 Union Carbide Corp Metal bodies of uniform porosity
US3443977A (en) * 1967-11-13 1969-05-13 Pfizer & Co C Anticorrosion pigments
US3562011A (en) * 1968-04-26 1971-02-09 Gen Electric Insulating coating comprising an aqueous mixture of the reaction product of chromium nitrate and sodium chromate,phosphoric acid and colloidal silica and method of making the same
US3761301A (en) * 1969-04-22 1973-09-25 L Sama Processes for producing ductile high temperature oxidation resistant composites
BE757262A (fr) * 1969-10-10 1971-04-08 Union Carbide Corp Couche metallique poreuse et procede pour la former
US3820966A (en) * 1970-05-05 1974-06-28 Naradi N P Diamond grinding layer for honing segments
US3869293A (en) * 1971-08-06 1975-03-04 Teleflex Inc Inorganic coating compositions and a method
FI57606C (fi) * 1971-08-11 1980-09-10 Teleflex Inc Kemiskt bestaendigt temperaturbestaendigt oorganiskt bestrykningslack
DE2435989C2 (de) * 1974-07-26 1982-06-24 Fried. Krupp Gmbh, 4300 Essen Verfahren zur Herstellung eines verschleißfesten, beschichteten Hartmetallkörpers für Zerspanungszwecke
US3967984A (en) * 1975-02-03 1976-07-06 United States Steel Corporation Method for treating coated ferrous substrates
FR2314267A1 (fr) * 1975-06-12 1977-01-07 Anvar Procede pour le traitement superficiel des aciers et produits obtenus
US3989863A (en) * 1975-07-09 1976-11-02 The International Nickel Company, Inc. Slurry coating process
US4108652A (en) * 1976-08-17 1978-08-22 Nippon Tungsten Co., Ltd. Method for producing a sintered body of high density
JPS5853068B2 (ja) * 1978-01-28 1983-11-26 工業技術院長 耐食性被覆された鉄又は鉄合金及びその製法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of EP0131045A4 *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0181409A1 (fr) * 1984-04-24 1986-05-21 Institut Organicheskogo Sinteza Akademii Nauk Latviiskoi Ssr Derives de 15(r+s)-fluor-11,15-didesoxyprostaglandine e 1?
EP0181409B1 (fr) * 1984-04-24 1989-02-08 Institut Organicheskogo Sinteza Akademii Nauk Latviiskoi Ssr Derives de 15(r+s)-fluor-11,15-didesoxyprostaglandine e 1?
WO1985005352A1 (fr) * 1984-05-24 1985-12-05 Höganäs Ab Corps fritte heterogene
US4659547A (en) * 1984-05-24 1987-04-21 Hoganas Ab Inhomogeneous sintered body
FR2613008A1 (fr) * 1987-03-23 1988-09-30 Dana Corp Couvercle pour frein d'embrayage, son procede de fabrication et frein d'embrayage associe
US4919243A (en) * 1987-03-23 1990-04-24 Dana Corporation Clutch brake having segmented cover surfaces
GB2324537A (en) * 1997-04-25 1998-10-28 Hitachi Powdered Metals Easily machined iron based sintered alloy
US5967110A (en) * 1997-04-25 1999-10-19 Hitachi Powered Metals Co., Ltd. Fe-based sintered alloy manufacturing process, Fe-based sintered alloy manufactured through thereof and bearing cap
GB2324537B (en) * 1997-04-25 2001-11-07 Hitachi Powdered Metals Fe-based or Fe-Cu-based alloy manufacturing process, Fe-based or Fe-Cu-based sintered alloy manufactured thereby, and bearing cap
WO2015112365A1 (fr) * 2014-01-24 2015-07-30 United Technologies Corporation Amélioration de poudre pour fabrication additive
US10005127B2 (en) 2014-01-24 2018-06-26 United Technologies Corporation Powder improvement for additive manufacturing

Also Published As

Publication number Publication date
CA1216197A (fr) 1987-01-06
EP0131045A1 (fr) 1985-01-16
JPS60500376A (ja) 1985-03-22
EP0131045A4 (fr) 1988-09-07

Similar Documents

Publication Publication Date Title
US4793968A (en) Surface modified powder metal parts and methods for making same
US8012598B2 (en) Metal foam body having an open-porous structure as well as a method for the production thereof
CN101585084B (zh) 烧结多孔体的生产方法
CA1103529A (fr) Traduction non-disponible
EP1304185A4 (fr) Article en metal poreux, materiau composite metallique utilisant cet article, et procede de production y relatif
JPS63109151A (ja) 高硬度複合材およびその製造方法
WO2007133536A2 (fr) Rouleaux de travail revêtus par pulvérisation thermique
CA2533118C (fr) Procede de fabrication de composants en alliage a base de nickel et composants ainsi fabriques
FI66553C (fi) Ythaerdningsstaong
US4562090A (en) Method for improving the density, strength and bonding of coatings
CA1216197A (fr) Pieces frittees modifiees en surface, et leur fabrication
CA1269575A (fr) Production de produits plats a partir de materiau en forme de particules
US5350107A (en) Iron aluminide alloy coatings and joints, and methods of forming
US6355207B1 (en) Enhanced flow in agglomerated and bound materials and process therefor
CA1301565C (fr) Methode de fabrication de moules de formage en graphite revetus
MXPA03010508A (es) Polvo de metal para el revestimiento termico de substratos.
KR100831827B1 (ko) 개방-다공성 구조를 가지는 금속 발포체 및 이의 제조 방법
JPH0256307B2 (fr)
KR20010005745A (ko) 내화제품의 제조방법 및 이에 의해 제조된 내화제품
SU1759557A1 (ru) Композиционный материал
CA1055732A (fr) Ebauches frittees pour le laminage et le forgeage; methode de fabrication
Väisänen et al. Microstructure and properties of TiC-CrNiMo SHS spray powder and thermally sprayed coating
JPH01184206A (ja) 板状多孔質焼結体の製造方法
Gidikova et al. Electrolyte coatings of chromium with nanodiamonds on sintered steels
JPS60116759A (ja) 耐摩，耐食性チタン・モリブデン系合金皮膜を形成する方法

Legal Events

Date Code Title Description
AK Designated states

Designated state(s): AU CH DE GB JP NL NO SE

AL Designated countries for regional patents

Designated state(s): AT BE CH DE FR GB LU NL SE

WWE Wipo information: entry into national phase

Ref document number: 1984900585

Country of ref document: EP

WWP Wipo information: published in national office

Ref document number: 1984900585

Country of ref document: EP

REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

WWW Wipo information: withdrawn in national office

Ref document number: 1984900585

Country of ref document: EP