High viscosity thermal protection materials summary report, 1 July 1969--30 June 1970. [20 v/o W--80 v/o silica, 20 v/o--80 v/o silica]

Technical Report · Fri Mar 05 04:00:00 EST 1971

OSTI ID:7318409

Wilson, R E

Vacuum hot-pressed nozzles of 20 v/o tungsten--80 v/o silica tested in the NOL oxy-hydrogen (H-O) rocket test motor out-performed the best of several ATJ graphite nozzles with a threefold increase in survival time. The ablation resistance varied with density and a minimum of 97% of the theoretical value was needed for satisfactory performance. However, the material performed badly in rocket motor tests using B47 (aluminized) propellant. Excessive throat erosion rate was believed to be caused by the aluminum in the propellant. H-O motor tests of vacuum hot pressed composites in which molybdenum replaced the usual tungsten showed it a poor substitute. A study of the effect of the tungsten-to-silica ratio of a series of hot-pressed composites revealed that both strength and elastic moduli increased with increased tungsten content. Substitution of fibrous tungsten for the entire 20 v/o of particulate tungsten in a hot-pressed composite produced no increase in mechanical properties although SEM studies revealed wetting of the fibers. Additions of 20 and 50 v/o of graphite fiber to hot-pressed silica resulted in a loss in strength of the silica due apparently to a carbon--silica reaction. (auth)

• Research Organization: Naval Ordnance Lab., White Oak, MD (USA)
• OSTI ID: 7318409
• Report Number(s): AD-882469; NOLTR-70-254
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
360205 -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
ABLATION
CARBON
CHALCOGENIDES
COMPOSITE MATERIALS
ELASTICITY
ELEMENTS
EROSION
FIBERS
GRAPHITE
MECHANICAL PROPERTIES
METALS
MOLYBDENUM
NONMETALS
NOZZLES
OXIDES
OXYGEN COMPOUNDS
REFRACTORY METALS
SILICON COMPOUNDS
SILICON OXIDES
TENSILE PROPERTIES
TRANSITION ELEMENTS
TUNGSTEN