(19)
(11) EP 0 233 574 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
26.07.1989 Bulletin 1989/30

(43) Date of publication A2:
26.08.1987 Bulletin 1987/35

(21) Application number: 87101816.4

(22) Date of filing: 10.02.1987
(51) International Patent Classification (IPC)4: C22C 32/00
(84) Designated Contracting States:
CH DE GB LI

(30) Priority: 12.02.1986 US 828801
20.02.1986 US 831200
20.02.1986 US 831201

(71) Applicant: GTE Products Corporation
Wilmington, DE 19801 (US)

(72) Inventors:
  • Ritsko, Joseph E.
    Towanda, PA 18848 (US)
  • Port, David J.
    Sayre, PA 18840 (US)
  • Houck, David L.
    Towanda, PA 18846 (US)
  • Kenney, Frank D.
    Wyalusing, PA 18853 (US)

(74) Representative: Grünecker, Kinkeldey, Stockmair & Schwanhäusser Anwaltssozietät 
Maximilianstrasse 58
80538 München
80538 München (DE)


(56) References cited: : 
   
       


    (54) Method for controlling the oxygen content in agglomerated molybdenum powder


    (57) A method is disclosed for introducing a controlled level of oxygen into agglomerated molybdenum metal powder, in particular into agglomerated molybdenum plasma spray powder. According to a first aspect of the invention, the method involves contacting the powder with a relatively dilute solution containing a sufficient amount of an oxidizing agent for a sufficient time to increase the oxygen content of the powder followed by removing the resulting partially oxidized powder from the resulting solution. According to a second aspect of the invention, the method involves heating the powder at a sufficient temperature for a sufficient time in the presence of water vapor, and a non-oxidizing atmosphere with the amount of non-oxidizing atmosphere being controlled to produce a partially oxidized molybdenum powder. According to a third aspect of the invention, the method involves forming a relatively uniform mixture of agglomerated powders consisting essentially of molydenum and one or more oxygen containing compounds of molybdenum wherein the mixture has an oxygen content of more than about 10% by weight and reducing the mixture at a sufficient temperature for a sufficient time to remove a portion of the oxygen therefrom and form a molybdenum powder having an oxygen content of no greater than about 10% by weight.







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