PHYSICAL METALLURGY OF TUNGSTEN AND TUNGSTEN BASE ALLOYS. Period covered: April 1, 1958 to November 30, 1959

Technical Report · Tue Dec 01 04:00:00 EST 1959

OSTI ID:4163040

Atkinson, R H

Base line data revealed that the tensile transition temperature of W is not strongly influenced by gaseous impurities of 10 to 50 ppm but may be affected by metallic impurities of 10 to 30 ppm. The recrystallization temperature of W (1300 to 1400 deg C for 30 anneals) was increased to approximately 1800 deg C by the presence of 50 ppm of Al. Trace impurity levels exhibited only slight influence on tensile behavior of W up to 2700 deg C, but at 2250 to 2700 deg C ductility decreased sharply with increasing temperature and was accompanied by an anomalous and poorly reproducible creep-rupture bebavior. Deformation of single crystals is accompanied by twinning. Low-temperature yield point phenomena were observed and are tentatively attributed to H. Polycrystalline W exhibited several low magnitude internal friction peaks of undetermined origin at 65, 150, 550, and 700 deg C. Single crystals after a 400 deg C anneal showed no peaks. Purposeful introduction of C and O into W at elevated temperatures did not produce homogeneous distributions of these elements in concentrations above 20 to 40 ppm. The addition of ThO/sub 2/ in concentrations of 2 to 4 wt.% increased the recrystallization temperature of W by 400 to 600 deg C and thereby increased the yield strength at 2700 deg F by a factor of 2 to 3.5 (to 33,000 psi) and the 100- hr creep rupture strength by a factor of 2. The addition of 0.38 wt.% TaC as a dispersed second phase in W increased the yield stress at 2500 deg F to 56,000 psi. (C.J.G.)

• Research Organization: Westinghouse Electric Corp. Lamp Div., Bloomfield, N.J.
• NSA Number: NSA-14-023306
• OSTI ID: 4163040
• Report Number(s): WADD-TR-60-37
• Country of Publication: United States
• Language: English

Related Subjects

ANNEALING
CARBON
CREEP
CRYSTALS
DEFORMATION
DISTRIBUTION
DUCTILITY
EFFICIENCY
ELEMENTS
ENRICHMENT
FRICTION
GASES
HIGH TEMPERATURE
HOMOGENEOUS REACTORS
HYDROGEN
IMPURITIES
LOW TEMPERATURE
METALS, CERAMICS, AND OTHER MATERIALS
OXYGEN
QUANTITY RATIO
RECRYSTALLIZATION
STRESSES
TANTALUM CARBIDES
TENSILE PROPERTIES
THORIUM OXIDES
TUNGSTEN