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
  • 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
  • C22C29/06—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 based on carbides, but not containing other metal compounds
• • 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
  • C22C29/06—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 based on carbides, but not containing other metal compounds
  • C22C29/067—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 based on carbides, but not containing other metal compounds comprising a particular metallic binder
• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B37/00—Cases
  • G04B37/22—Materials or processes of manufacturing pocket watch or wrist watch cases

Definitions

• the present invention relates to a sintered alloy based on carbides and comprising a binder, as well as articles made of this alloy, in particular decorative articles.
• Hard sintered metal alloys comprising at least one carbide and a metal binder are already known on the one hand for the manufacture of cutting tools and on the other hand for the production of decorative articles.
• patent CH 517,963 discloses the production of a watch case made of a sintered hard metal based on carbides, which has, thanks to its high hardness (greater than that of topaz), excellent scratch resistance characteristics.
• patents FR 2,487,380 and GB 1,282,009 respectively describe sintered anti-abrasive alloys based on carbides, nitrides and / or borides, which contain in their binder at least one precious metal, for example Au, Ag, Pd or Pt, usable for the production of decorative articles resistant to abrasion and having the aesthetic appearance of a precious alloy.
• precious metal for example Au, Ag, Pd or Pt
• the object of this invention is to provide a sintered alloy of the aforementioned type, that is to say very hard, but having improved anti-corrosion properties and a density close to that of stainless steel, in particular in order to be able to replace the latter in the production of scratch-resistant decorative items such as watch boxes and bracelets, bracelets and chains, lighters, pens, etc.
• the carbide-based sintered alloy having a density close to that of steel, object of this invention and aimed at achieving the above-mentioned object is characterized by the fact that it comprises 75 to 90% by weight of a mixture of carbides, and 10 to 25% by weight of a binder, 60 to 70% by weight of cobalt, nickel and ruthenium, and 30 to 40% in weight of molybdenum carbide, and the Ru being present in an amount of 10 to 25% relative to the total of the three elements Co, Ni and Ru.
• the mixture of carbides preferably consists of WC and TiC and may comprise, in place of part of the carbides, at least one nitride and / or at least one boride.
• the WC-TiC mixture can also consist of a mixed compound of these two carbides.
• the Mo 2 C can possibly be partially replaced by HfC.
• Example 1 The four alloys described in Example 1 were subjected to a Vickers - HV 10 type hardness test according to ISO 3768 standards. The results obtained are collated in the table below, with the relative densities of these alloys:
• Example 1 The four alloys Nos. l to 4 described in Example 1, as well as the following four reference alloys Nos. 5 to 8, were subjected to corrosion tests.
• Reference alloys Nos. 5 to 8 83% of WC-TiC and 17% of binder, including 5% of Mo 2 C and 12% respectively of Ni-Ru (alloy No. 5), of Ni (alloy No. 6), of Co ( alloy No. 7) and Co-Ni (alloy No. 8).
• Breaking strength tests were carried out according to ISO 3327 standards for the four Nos alloys. 1 to 4 (invention) and the four reference alloys Nos 5 to 8.
• the surface condition of the alloys according to the invention (Nos. 1 to 4) and of the reference alloys (Nos 5 to 8) was examined, after polishing the samples until polishing by means of a diamond paste l ⁇ , on the one hand by observation under a microscope and on the other hand by carrying out comparative roughness tests.
• alloys according to the invention had an A o B o C o porosity (ASTM standards) and an average grain size of the order of 5 to 10 p, while the alloys standards had a porosity A 1 B 0 C 1 and an average grain size less than about 3p.
• alloys Nos 1 to 4 the average values obtained were between 0.05 and 0.1 ⁇ m, while for alloys Nos 5 to 8 (reference), they were of the order of 0.2 to 0.3p. This therefore means that, under identical polishing conditions, the alloys according to the invention have a roughness significantly lower than that of the reference alloys.
• the sintered alloys according to the invention are particularly suitable for the production of decorative articles such as watch boxes and straps, bracelets and chains, lighters, pens, etc.
• the alloy articles according to the invention have, after polishing, a remarkable shiny surface.
• This property of being able to be polished which the alloys according to the invention exhibit is due to an average size. grains after sintering which is higher than that of known alloys.
• the quality of the surface gloss after polishing therefore also comes from the average grain size and the relatively low porosity of these alloys.
• the alloys according to the invention therefore have values of porosity and average grain size such that they make it possible to obtain an optimal compromise between the gloss or the shine of the polished surface of these alloys, their hardness and the resistance to breaking.
• the alloys according to the invention still have the advantage over the sintered hard metal alloys already used for this purpose of being able to be obtained by pressing and sintering at 1350 -1500 ° C under a relatively low pressure (0.1 - 1 Torr), while said known alloys must be sintered at 1450 - 1500 ° C under a relatively high pressure (greater than 1 Torr).

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Powder Metallurgy (AREA)
• Ceramic Products (AREA)
• Cutting Tools, Boring Holders, And Turrets (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)

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Publications (2)

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Cited By (4)

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Citations (6)

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• 1983
  • 1983-03-15 CH CH142183A patent/CH653204GA3/fr unknown
• 1984
  • 1984-03-06 EP EP84102398A patent/EP0121769B1/de not_active Expired
  • 1984-03-06 AT AT84102398T patent/ATE27618T1/de not_active IP Right Cessation
  • 1984-03-06 US US06/586,790 patent/US4574011A/en not_active Expired - Fee Related
  • 1984-03-06 DE DE8484102398T patent/DE3464063D1/de not_active Expired
  • 1984-03-06 DE DE198484102398T patent/DE121769T1/de active Pending

Patent Citations (6)

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