ALLOYS OF TANTALUM DIBORIDE WITH IRON, COBALT, AND NICKEL

Journal Article · Sat Apr 01 04:00:00 EST 1961 · Planseeber. Pulvermet.

OSTI ID:4000660

Lavendel, H W

Iron, cobalt, and nickel form with tantalum diboride similar quasibinary systems, with two intermediate compounds of the same composition, MTaB/sub 2/ and M/sub 5/TaB/sub 2/ (where ""M"" stands for Fe, Co, or Ni), and an M/sub 5/TaB/sub 2//M eutectic contairing 77.6 atom percent of the metal. The compounds are formed in the peritectic reactions TaB/sub 2/ + liquid = MTaB/sub 2/, and MTaB/ sub 2/ i liquid = M/sub 5/TaB/sub 2/. In the case of iron and cobalt, at temperatares above 1400 deg C and at pressures up to 1 atmosphere, the MTaB/sub 2/ decomposes into TaB/sub 2/ + vapor. The temperatare of the NiTaB/sub 2/ peritectic lies near l5OO deg C, all three M/sub 5/TaB/sub 2/ peritectics fall between 1170 and 1180 deg C, and all three eutectics between 1090 and 1130 deg C. The crystal structures of the cobalt and nickel compounds are isomorphous; the structares of the M/sub 5/TaB/sub 2/ compounds of cobalt and nickel are face centered cubic (a/sub 0/ = 10.56/sub 5/ A), the structures of the MTaB/sub 2/ compounds have not been identified. The crystal structares of FeTaB/sub 2/ and Fe/sub 5/TaB/sub 2/ are also unknown. (auth)

• Research Organization: Lockheed Missiles and Space Div., Palo Alto, Calif.
• NSA Number: NSA-15-019926
• OSTI ID: 4000660
• Journal Information: Planseeber. Pulvermet., Journal Name: Planseeber. Pulvermet. Vol. Vol: 9
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

COBALT ALLOYS
CONFIGURATION
CRYSTALS
EUTECTICS
HIGH TEMPERATURE
INTERMETALLIC COMPOUNDS
IRON ALLOYS
LATTICES
METALS, CERAMICS, AND OTHER MATERIALS
NICKEL ALLOYS
PHASE DIAGRAMS
PRESSURE
TANTALUM BORIDES