Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
  • C22C27/04—Alloys based on tungsten or molybdenum
• • 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
  • C22C1/045—Alloys based on refractory metals

Definitions

• This invention relates to tungsten base alloys characterized by high strength at elevated temperatures and low ductile-brittle transition temperatures.
• the tungsten base alloys of the present invention contain rhenium, carbon and a reactive metal selected from Group IV-A of the Periodic Chart.
• rhenium As is well known, the addition of rhenium to tungsten produces alloys having reduced ductile-to-brittle transition temperatures.
• the scarcity and high cost of rhenium has limited the use of these materials for many applications such as sheet, tubing and other wrought forms.
• tungsten base alloys which contain between 1% and 10% rhenium, 0.002% to 0.05% carbon and a reactive metal selected from the group consisting of hafnium, zirconium and titanium.
• the percentage of reactive metal in the alloy depends on the metal used, hafnium being present in an amount between 0.01% and 1.0%, zirconium 0.01% to 0.3% and titanium 0.03% to 0.3%. (All percentages given are by Weight.)
• the ductile-to-brittle transition occurs in the range from less than 50 C. to C. for the new alloys as compared to C. for unalloyed tungsten.
• the recrystallization temperature for unalloyed tungsten is between 1450 C. and 1500 C. whereas the present alloys have recrystallization temperatures in the range 1600 C. to 1850 C.
• the high strengths and high recrystallization temperatures obtained in these tungsten base alloys is believed due to the formation during fabrication of a uniformly dispersed reactive metal carbide having particle size predominantly in the range 50 to 1000 Angstroms.
• Elemental powders of carbon, rhenium and tungsten were blended with hafnium hydride to form a uniform mixture which was then subjected to a pressure of approximately 50,000 pounds per square inch to form a billet.
• the billet was next sintered at a temperature of about 2350 C. for approximately 4 hours to mutually diffuse the different ingredients thereby forming a solid solution of hafnium and rhenium in tungsten, the carbon probably being partitioned between tungsten carbide and a solid solution of carbon in tungsten.
• the billet was then fabricated by forging at a temperature of approximately 1850 C. from 0.05 inch to 0.3 inch thick followed by rolling at a temperature of about 1550 C. to form sheets having a thickness of approximately 0.040 inch. During the fabrication process, carbon precipitates as a finely dispersed reactive metal carbide.
• the alloys may also be consolidated by other suitable processes such as vacuum arc-casting. Fabrication may be accomplished by other techniques such as extruding, forging or drawing .to produce the desired wrought form.
• EXAMPLE III sisting essentially of from 1% to 10% rhenium, 0.002% An alloy consisting of carbon, rhenium, titanium and to 095% f f from 0-01% to 10% hafmum the tungsten was prepared by the method of Example I.
• Table balance Consisting of tungsten- 1v gives the characteristics of various compositions of this A tungsten base alloy characterized y high strength alloy, at elevated temperatures and a low ductile-to-brittle tran- TABLE IV Alloy Percent By Weight Ultimate Duetile-to-Brittle Transition One Hour Tensile Temp. C.) Reerystall. Strength at Temperature Ti Re 0 W 1,050 o. (p.s.i.) Nil Duet. Duetility 0.)
• the alloys also have high to 0.05% carbon, from 0.01% to 0.3% zirconium, the recrystallization temperatures as compared to unalloyed balance consisting of tungsten. tungsten. For applications Where a high melting point is 5.
• conand titanium the balance consisting of tungsten. sisting essentially of from 3% to 10% rhenium, 0.002% 2.
• a tungsten base alloy characterized by high strength to 0.02% carbon, from 0.01% to 0.25% zirconium, the at elevated temperatures and a low ductile-to-brittle tranbalance consisting of tungsten.
• a tungsten base alloy characterized by high strength at elevated temperatures and a low ductile-to-brittle tran sition temperature in the range -50 C. to +125 C. consisting essentially of from 1% to 10% rhenium, 0.002% to 0.05% carbon, 0.01% to 1.0% of a reactive metal selected from the group consisting of hafnium, zirconium and titanium, the balance consisting of tungsten, said alloy containing uniformly dispersed particles of reactive metal carbide having particle sizes predominantly in the range 50 to 1000 Angstroms.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Powder Metallurgy (AREA)
• Manufacture And Refinement Of Metals (AREA)

Priority Applications (10)

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Publications (1)

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Family Applications (1)

Country Status (9)

Cited By (5)

Citations (3)

• 1965
  • 1965-03-29 US US443690A patent/US3395013A/en not_active Expired - Lifetime
• 1966
  • 1966-03-25 SE SE4008/66A patent/SE303382B/xx unknown
  • 1966-03-25 DK DK155866AA patent/DK116174B/da unknown
  • 1966-03-25 DE DE19661533346 patent/DE1533346B1/de active Pending
  • 1966-03-25 CH CH431466A patent/CH442763A/fr unknown
  • 1966-03-25 NL NL6603946A patent/NL6603946A/xx unknown
  • 1966-03-25 BE BE678439D patent/BE678439A/xx unknown
  • 1966-03-25 ES ES0324652A patent/ES324652A1/es not_active Expired
  • 1966-03-28 AT AT292066A patent/AT265675B/de active

Patent Citations (3)

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