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Deformation structures of polycrystalline slightly strained tungsten, tungsten rhenium, and tungsten tantalum alloys examined by transmission electron microscopy
Deformation substructures of W, W-Re and W-Ta alloys, using transmission electron microscopy
Report describes methods for the fabrication of tungsten and tungsten alloys into small-diameter, thin-wall tubing of nuclear quality. The tungsten, or tungsten alloy tube blanks are produced by double extrusion. Plug-drawing has emerged as an excellent secondary fabrication technique for the reduction of the overall tube dimensions.
Surface studies have been made of multilayer and monolayer films of barium and barium oxide on a tungsten substrate. The purpose of the investigation was to synthesize the surface conditions that exist on an activated impregnated tungsten cathode and obtain a better understanding of the mechanism of operation of such cathodes. The techniques employed in these measurements were Auger spectroscopy and work-function measurements. The results of this study show that the surface of an impregnated cathode is identical to that observed for a synthesized monolayer or partial monolayer of barium on oxidized tungsten by evaluating Auger spectra and work-function measurements. Data obtained from desorption studies of barium monolayers on a tungsten substrate in conjunction with Auger and work-function results have been interpreted to show that throughout most of its life an impreganated cathode has a partial monolayer, rather than a monolayer, of barium on its surface.
The tensile behavior of a 200-micrometer-diameter tungsten lamp (218CS-W), tungsten + 1.0 atomic percent (a/o) thoria (ST300-W), and tungsten + 0.4 a/o hafnium carbide (WHfC) wires was determined over the temperature range 1300 t0 1600 K at strain rates of 3.3 X 10 to the -2 to 3.3 X 10 to the -5/sec. Although most tests were conducted on as-drawn materials, one series of tests was undertaken on ST300-W wires in four different conditions: as-drawn and vacuum-annealed at 1535 K for 1 hr, with and without electroplating. Whereas heat treatment had no effect on tensile properties, electropolishing significantly increased both the proportional limit and ductility, but not the ultimate tensile strength. Comparison of the behavior of the three alloys indicates that the HfC-dispersed material possesses superior tensile properties. Theoretical calculations indicate that the strength/ductility advantage of WHfC is due to the resistance to recrystallization imparted by the dispersoid.
Tungsten coating from the thermal decomposition of tungsten bromides
High purity, cylindrical castings of high melting point materials such as tungsten and tungsten alloys
Coating-to-substrate bonding between plasma sprayed tungsten and preheated tungsten substrates
Metallurgical bonding between plasma sprayed tungsten & hot tungsten substrates - interface & recrystallization
Mechanical properties and recrystallization of electron-beam-melted tungsten and arc-melted tungsten
Influence of boron additions on physical and mechanical properties of arc-melted tungsten and of tungsten-tantalum alloy
Mechanical properties of tungsten and tungsten rhenium alloys
Compatibility tests of molten uranium with tungsten and tungsten-1.5 percent hafnium
Tungsten and tungsten alloy single crystal deformations determined as function of alloying, strain, and temperature
High temperature tensile properties of arc-melted and extruded binary alloys of tungsten with tantalum, molybdenum and columbium
Radiation and accommodation coefficients of tungsten by hot filament method
Ductility enhancement of tungsten by rhenium addition due to modification of grain boundary precipitate morphology
Rocket nozzle throat insert encapsulated in solid tungsten case