Classifications

• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
  • C25D3/00—Electroplating: Baths therefor
  • C25D3/02—Electroplating: Baths therefor from solutions
  • C25D3/50—Electroplating: Baths therefor from solutions of platinum group metals
• • 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
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/9265—Special properties
  • Y10S428/929—Electrical contact feature
• • 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
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/922—Static electricity metal bleed-off metallic stock
  • Y10S428/9335—Product by special process
  • Y10S428/934—Electrical process
  • Y10S428/935—Electroplating

Definitions

• My invention relates to methods of electrolytically coating metallic objects, particularly molybdenum, with platinum.
• molybdenum has been plated with platinum using electrolytic baths containing in addition to a platinum salt, another metal salt, such as a lead salt, capable of increasing the platinum deposit from the bath.
• a platinum salt such as a lead salt
• some of the metal other than platinum is plated out together with the platinum and cannot be separated from the platinum in the coating. This is highly disadvantageous for certain purposes namely where the molybdenum object is to serve as an electrode of an electric discharge tube.
• a principal object of my invention therefore, is to develop a process for electrolytically coating metallic objects with platinum which eliminates the presence of any undesired metallic contaminate in the finally sintered platinum layer.
• a second principal object of my invention is to increase the platinum output of the electrolytic bath used in coating metallic objects with platinum.
• Still another object of my invention is to increase the thickness of the platinum layer deposited by the electrolytic process.
• the electrolytic coating step I prefer to utilize a relatively high current density i: e. 50-150 amps./cm.
• the object to be coated is molybdenum
• this initial thin layer may then be coated by subsequent thick layers.
• Example A molybdenum wire having a thickness of 175 .0 was passed through an electrolytic bath 30 cms. in length consisting of an aqueous solution containing 240 gms. of chloroplatinic acid and 7 gms. of mercuric chloride per liter, at a speed of meters per hour. During this operation a current of 1.5 amps. was passed through the solution, the molybdenum wire being connected to the cathode.
• the wire After sintering at 1000 C. the wire was found to have a coating of substantially pure platinum from 0.5 to 0.7 thick. By repeating this operation a number of times it was found possible to build up substantially pure, dense platinum layers up to 10p. thick.
• a method of electrolytically coating a metallic object with platinum comprising the steps, immersing the metallic object in an electrolytic bath comprising an aqueous solution of chloroplatinic acid (H PtCl and mercuric chloride, the concentration of the chloroplatinic acid being from about to 300 gms. per liter and the concentration of the mercuric chloride being about 1 to 15 gms. per liter, while passing a suitable current through the bath for a time sufficient to deposit a layer of platinum black of the desired thickness, and sintering said layer at a temperature of about 1000 C. to convert it to platinum substantially free of mercury.
• chloroplatinic acid H PtCl and mercuric chloride

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Electroplating And Plating Baths Therefor (AREA)
• Electroplating Methods And Accessories (AREA)
• Electrolytic Production Of Metals (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=19785034

Family Applications (1)

Country Status (7)

Cited By (5)

Citations (1)

• 0
  • BE BE551868D patent/BE551868A/xx unknown
  • NL NL87771D patent/NL87771C/xx active
• 1956
  • 1956-09-18 US US610675A patent/US2847372A/en not_active Expired - Lifetime
  • 1956-10-16 DE DEN12846A patent/DE1033478B/de active Pending
  • 1956-10-16 GB GB31465/56A patent/GB810818A/en not_active Expired
  • 1956-10-17 CH CH350850D patent/CH350850A/de unknown
  • 1956-10-17 FR FR1158715D patent/FR1158715A/fr not_active Expired

Patent Citations (1)

Also Published As

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