THE VAPORIZATION AND PHYSICAL PROPERTIES OF CERTAIN REFRACTORIES. PART II. EXPERIMENTAL STUDIES

Technical Report · Sat Jul 01 04:00:00 EDT 1961

OSTI ID:4740673

Hasapis, A A; Melveger, A J; Panish, M B; Reif, L; Rosen, C L

The vapor pressure-temperature relationships for iridium, rhodium, ruthenium, iridium plus carbon, alumina, thoria, and hafnia were studied by simple effusion and mass spectrometric methods. Vapor phase species were identi fied. The vapor pressure data and derived heats of vaporization and reaction are presented. The vaporization modes of the rare earth sesquioxides were studied mass spectroscopically and data are given which demonstrate that the mode of vaporization of these materials is strongly dependent upon the number of electrons in the 4f shell of the rare earth metal. Continuously monitored effusion experiments conducted on the Mo--Si system yielded the following heats of dissociati on in kcal/gm atom Si at 298 deg K. o/sub 5/Si/sub 3/-Mo/sub 5/Si, 128.3; Mo/sub 3/Si --Mo, 132.9. Continuously monitored experiments on the W--Si system yielded the following approximate dissociation pressures in atms. at 1765 deg K: liquidWSi/sub 2/, 3.5 X 10/sup -6/; WSi/sub 2/--W/sub 3/Si/sub 2/, 2.6 x 10/sup -6/; W /sub 3/Si/sub 2/--W, 1.7 x 10/sup -6/. The surface tensions of silica and silica plus 1% oxide additives and zirconium plus uranium have been measured by a sessile drop technique. The viscositi es of alumina, zirconium plus uranium, pure silica, silica plus 1% V/sub 2/O/sub 5/, silica plus 1% CoO, and silica plus 1% Al/sub 2/O/sub 3/, h ave been determined. (auth)

• Research Organization: Avco Corp. Research and Advanced Development Div., Wilmington, Mass.
• NSA Number: NSA-17-004933
• OSTI ID: 4740673
• Report Number(s): WADD-TR-60-463(Pt.II)
• Country of Publication: United States
• Language: English

Related Subjects

ADDITIVES
ALUMINUM OXIDES
ATOMIC MODELS
CARBIDES
COBALT OXIDES
DECOMPOSITION
DIFFUSION
ELECTRONS
EVAPORATION
HAFNIUM OXIDES
HIGH TEMPERATURE
IMPURITIES
IRIDIUM
MASS SPECTROMETERS
MEASURED VALUES
MECHANICS
METALS, CERAMICS, AND OTHER MATERIALS
MOLYBDENUM COMPOUNDS
MONITORING
OXIDES
PRESSURE
RARE EARTHS
REFRACTORIES
RHODIUM
RUTHENIUM
SILICIDES
SILICON OXIDES
SURFACE TENSION
TEMPERATURE
THERMODYNAMICS
THORIUM OXIDES
TUNGSTEN COMPOUNDS
VANADIUM OXIDES
VAPORS
VISCOSITY