Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
  • C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
  • C22C32/0015—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
  • C22C32/0021—Matrix based on noble metals, Cu or alloys thereof
• • 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
  • B22F2998/10—Processes characterised by the sequence of their steps
• • 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
  • Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
  • Y10T428/12771—Transition metal-base component
  • Y10T428/12861—Group VIII or IB metal-base component
  • Y10T428/12875—Platinum group metal-base component

Definitions

• the invention relates to a process for the preparation of a finely divided by, small particles made of base metal oxide dispersion strengthened platinum material, welded, in particular at least one inner wall having molding, in particular a pipe, a shaped body, in particular a tube, and the use of such a tube.
• Suitable base metals are, for example, chromium, beryllium, magnesium, aluminum, Silicon, the rare earths, thorium, uranium and metals of the first, second and third subgroup periods, Calcium to nickel, strontium to molybdenum and barium to tantalum.
• the High temperature resistant compound may be an oxide, a carbide, a nitride, a silicide Boride, a sulfide or any other compound that is due to interaction between a gaseous phase and the base metal can be formed.
• DD132673 relates to a process for the preparation of platinum appliances. To Production of the finished workpiece takes place at high temperatures In the air, for example, the user experiences internal oxidation of the finished device.
• platinum materials with a fine-grained equi-structure in the production used by components.
• This structure is created by a molten and cast Ingot formed (eg by forging, rolling) and then a recrystallization annealing is subjected.
• a recrystallization annealing is subjected.
• Upon subsequent welding of the material is formed after solidification of the metal in the weld a structure, rather with the unwanted Structure in cast ingots is comparable, as with the fine recrystallized structure of the remaining material.
• By reshaping the weld together with the rest of the material it is possible to achieve a homogenization of the microstructure after a recrystallization annealing treatment becomes visible, d. h., That the deformed and recrystallized material of the weld essentially corresponds to the rest of the material.
• the solidifying effect of the dispersoids will no longer be present.
• the structure in an annealing treatment or when used at high temperature (Grain size) in the largely oxide-free weld significantly coarser than in the rest Be material.
• the presence of the dispersoids leads to a considerable stabilization of the Grain structure).
• a blank of any shape, made with yttrium and zirconium and / or cerium-doped platinum-base metal alloy consists, first in one Vorform brought, in particular a sheet to a tube rounded and the respective Ends are welded together. Welding can be done either without additional metal or be carried out with a similar additional metal. "Same type of additional metal” means if, when welding, the addition of weld metal is required, this metal should be similar to the base material, d. h., With the specified base metal doping elements, here: zirconium and yttrium, cerium, should be alloyed.
• the mold still in the preform is in an oxidizing Heat treated medium to a minimum degree of oxidation of the base metal of 75% by weight, wherein preferably an atmosphere of air, oxygen, water vapor or a mixture from water vapor and hydrogen, noble gas, especially helium or argon, or nitrogen is used.
• the oxide-forming base metal components are very reactive, they may be necessary for the formation of the oxides Oxygen also other oxygenated compounds take such.
• the oxygen-containing medium must deliver it to the base metal components can, d. H. thermodynamically seen that the zirconium-yttrium and cerium oxides more stable must be as the oxygenated species in the medium. To ensure that not the Oxygen supply from the medium, but the diffusion in the platinum material rate-determining should be given a sufficient concentration of the oxygenated species be.
• the doped unoxidized material is first of all welded and then the oxide dispersoids by the heat treatment in a generated oxidizing medium.
• the internal oxidation becomes accelerated so far that the oxidation treatment on the molded and welded preform body can be carried out.
• the formation of the oxide particles is only slightly different from the grain structure of the platinum material affected, d. h., That the only significant difference between the weld and the Base material in the grain structure and not in the distribution of oxide particles.
• the mold is in the preform according to the desired Endform, for example, by rolling, forging or stretching accordingly shaped, wherein especially the Walzdschreibmaschine has proven during stripping.
• the formed preform body is subjected to a recrystallization annealing treatment subject to minimize dimensional changes in use.
• a recrystallization annealing treatment subject to minimize dimensional changes in use.
• the Uniformity of the structure between weld and base material through this treatment obvious.
• the welded structure treated in this way and the dispersion-strengthened one Platinum material differ only insignificantly in their properties from each other.
• the annealing treatment can be any oxide dispersion strengthened, otherwise unalloyed platinum at any Temperature ⁇ 600 ° C.
• PtRh, Pt-Au and Ptlr alloys - these are For platinum-precious metal alloys - temperatures ⁇ 900 ° C, often ⁇ 1000 ° C, are required.
• the annealing treatment can in principle also at even higher temperatures are carried out because the oxide dispersoids too strong Prevent grain enlargement. As a practicable upper limit has a temperature of 1400 ° C proved. If the material is exposed to too high a temperature before the Oxide dispersoids formed by internal oxidation, it may be undesirable Grobkom Struktur come.
• a reduction in wall thickness of at least 50% is achieved because of the properties the weld structure and the dispersion-hardened platinum material are virtually non-existent more different from each other.
• the deformed Preform a uniform structure on.
• the base metal content of the platinum-base metal alloy 0.005 to 1% by weight
• the dispersion strengthened platinum material is dispersion strengthened Platinum-rhodium alloy, dispersion strengthened platinum-iridium alloy or dispersion strengthened platinum-gold alloy.
• the platinum-base metal alloy with 0.1 to 0.2% by weight of zirconium and 0.01 to 0.05% by weight of yttrium and / or 0.05-0.2 Weight% cerium is doped and that the platinum-rhodium alloy is a PtRh10 alloy, the Platinum-gold alloy is a PtAu5 alloy and the platinum-iridium alloy is one Ptlr (1-10) -, in particular, a Ptlr (3-10) alloy is (PtXn means: (100-n) weight% Pt and n% by weight of element X).
• the shaped bodies produced by the process according to the invention in particular pipes, have the above-mentioned surprising and advantageous properties.
• a sheet (dimensions: 400 mm long, 350 mm wide, 3 mm thick) made of one with 0.18% by weight zirconium and 0.017 weight percent yttrium doped, unoxidized platinum material is rounded and Welded without additional metal over the length, in order in this way a Vorrohr with a Length of 400 mm and an inner diameter of about 111 mm.
• This Vorrohr becomes a heat treatment in an oxidizing medium, which is composed from dry air at a temperature of 1000 ° C for a period of 300 hours, until the oxygen content of the material is 0.073% by weight, on a cylindrical Mandrel with a diameter of 110 mm drawn from hardened tool steel and finally stretched to the desired length and wall thickness. The stretching takes place here through a pulling mandrel.
• the front pipe is to a wall thickness of 0.7 mm and a length formed by 1500 mm.
• the tube can be several longitudinal or Include round welds.
• This Way tubes up to a diameter of about 650 mm and a length of about 8000 mm are produced, and this information should not be considered as limiting.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Arc Welding In General (AREA)
• Powder Metallurgy (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

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• 1998
  • 1998-03-28 DE DE19813988A patent/DE19813988C1/de not_active Expired - Fee Related
• 1999
  • 1999-03-10 US US09/266,142 patent/US6129997A/en not_active Expired - Lifetime
  • 1999-03-11 DE DE59912028T patent/DE59912028D1/de not_active Expired - Lifetime
  • 1999-03-11 EP EP99104851A patent/EP0947595B1/de not_active Expired - Lifetime
  • 1999-03-24 CZ CZ0104899A patent/CZ298305B6/cs not_active IP Right Cessation
  • 1999-03-29 JP JP08631399A patent/JP3302654B2/ja not_active Expired - Fee Related

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