Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
  • H01T13/00—Sparking plugs
  • H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
  • H01T13/39—Selection of materials for electrodes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26D—CUTTING; DETAILS COMMON TO MACHINES FOR PERFORATING, PUNCHING, CUTTING-OUT, STAMPING-OUT OR SEVERING
  • B26D3/00—Cutting work characterised by the nature of the cut made; Apparatus therefor
  • B26D3/18—Cutting work characterised by the nature of the cut made; Apparatus therefor to obtain cubes or the like
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/04—Making non-ferrous alloys by powder metallurgy
  • C22C1/0466—Alloys based on noble metals
• • 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
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
  • H10N10/80—Constructional details
  • H10N10/85—Thermoelectric active materials
  • H10N10/851—Thermoelectric active materials comprising inorganic compositions
  • H10N10/854—Thermoelectric active materials comprising inorganic compositions comprising only metals

Definitions

• This invention relates to platinum, or any of the following allied metals in the platinum group, namely, rhodium, iridium, ruthenium, and palladium, and to alloys in which any of these metals forms the principal ingredient.
• the invention also relates to articles made from such metals or alloys and required to be able to withstand high temperatures and corrosive actions, such as sparking plug electrodes, thermocouples, electric furnace heating elements, and wire gauzes foruse as catalyst gauzes in chemical operations. to minimise the normal tendency of the initially fine-grained structure of such metals or their alloys to change into a coarse-grained structure when subjected to high temperatures with consequent deterioration of their mechanical properties.
• the invention consists of a material, or an article made therefrom, in the form of a compacted and sintered agglomerate of platinum or any of the allied metals above specified or an alloy thereof, and refractory oxide, the constituents being initially in a finely divided condition.
• I may use commercially pure platinum, but preferably I use an alloy containing for example, about rhodium, or about 4% tungsten, or up to 30% iridium, or up to 30% ruthenium, the balance being platinum.
• the required finely divided condition is obtained by any known and suitable process such as precipitation, or decomposition and reduction in hydrogen, and the metal in this condition is intimately mixed with any suitable and finely divided oxide, such as alumina, thoria,
• the refractory oxide, or compound adapted to produce it subsequently is mixed with a compound of the metal (or compounds of the metals) before the reduction or decomposition.
• Thequantity of oxide required is usually from about 0.1% to 1% of the weight of the metal, and preferably about 0.25%. The best amount for any particular purpose is readily ascertainable by experiment. If too little is used there will be insuflicient control of grain growth; if too much is used the resulting metal will be difficult to shape by swaging, rolling or drawing.
• the mixture is then compacted by pressure, sintered, and subsequently swaged, rolled, drawn, or otherwise
• the object of the invention is rhodium, and thorium oxide.
• thorium nitrate containing 0.5 gram of thorium oxide (ThOz).
• ThiOz thorium oxide
• the resultant paste is evaporated to dryness with constant stirring to ensure a uniform distribution of the constituents.
• the dried mass is then heated in a current of hydrogen at about 850 C. to decompose the rhodium and the thorium salts,.leaving an intimate mixture of platinum,
• the product is sieved, packed into a steel mould and compressed under a pressure of about tons per square inch in order to form a coherent mass.
• the compressed material is then heated at about 1400-1550 C.
• I employ 96 grams of platinum dissolved in aqua regia, a solution of ammonium tungstate containing 4 grams of tungsten, and another or the same solution containing thorium nitrate having 0.2% grams of thorium oxide.
• the tungsten and thorium solutions are added to the platinum solution, and after neutralising with ammonia, the mixture is evaporated to dryness.
• the resulting powder is heated at about 800 C. in air and then heated to about 1000 C. in hydrogen.
• the product consisting of finely divided platinum, tungsten and thorium oxide is formed into a bar by pressing in a steel mould at about 50 tons per square inch. The bar is then sintered in hydrogen for about two hoursat about 1450 C. and finally swaged, rolled or drawn to the required form and dimensions.
• Materials made in accordance with the invention are characterised by having a higher tensile strength and greater hardness than corresponding materials made in the usual way, and by a crystalline structure which is satisfactorily stable at high temperatures.
• the platinum, and platinum alloys produced in accordance with my invention are especially useful for use as sparking plug electrodes. They are also useful for thermo-couples, furnace heating elements, catalyst gauzes, and other articles required to resist high temperatures (of the order of 1000" C. or more), or corrosive actions under which metals produced in ordinary ways are liable to coarsening of the grain structure or other deterioration resulting in weakening such mechanical properties as strength or hardness.
• a material as claimed in claim 2 which contains platinum alloyed with about 10% of rhodium, and about 0.5% of thorium oxide.
• a material as claimed in claim 2 which contains platinum alloyed with about 4% of tungsten, and about 0.2% of thorium oxide.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Life Sciences & Earth Sciences (AREA)
• Forests & Forestry (AREA)
• Inorganic Chemistry (AREA)
• Powder Metallurgy (AREA)
• Catalysts (AREA)
• Spark Plugs (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=9725709

Family Applications (1)

Country Status (9)

Cited By (59)

Families Citing this family (6)

• 0
  • DE DENDAT838067D patent/DE838067C/de not_active Expired
  • IT IT460208D patent/IT460208A/it unknown
  • LU LU28048D patent/LU28048A1/xx unknown
• 1942
  • 1942-02-07 GB GB1654/42A patent/GB578956A/en not_active Expired
• 1943
  • 1943-03-09 US US478552A patent/US2406172A/en not_active Expired - Lifetime
• 1946
  • 1946-07-05 CH CH266685D patent/CH266685A/de unknown
  • 1946-07-10 NL NL126447A patent/NL69608C/xx active
  • 1946-07-11 BE BE466569D patent/BE466569A/xx unknown
  • 1946-07-12 FR FR941701D patent/FR941701A/fr not_active Expired

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