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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Bronze wool pads, impregnated with silicon rubber, meet the requirement for a thermally conductive, shock and vibration absorbing material. They serve as spacers in equipment mounting and are resistant to high temperatures.
Pressure molding tungsten microspheres is accomplished by applying hydraulic pressure to a silicone rubber mold insert with several barrel shaped chambers which is placed in a steel die cavity. This technique eliminates castings containing shear fractures.
Portable vacuum-operated apparatus leak-tests and sterilizes rubber gloves. The gloves are fitted to the hands directly from the apparatus without external handling.
Compact-vibration damping systems, consisting of rubber-coated metal bellows with a sliding O-ring connector, are used in vacuum lines. The device presents a metallic surface to the vacuum system and combines flexibility with the necessary stiffness. It protects against physical damage, reduces fatigue failure, and provides easy mating of nonparallel lines.
Plug assembly seals openings in piping systems, vessels, and chambers for low pressure leak testing. The assembly, which consists of a rubber sealing plug and the mechanism for expanding it into a pressure-tight configuration, adequately seals irregular diameters without damage to mating surfaces.
Silicone rubber gasket and an alumina gasket retain a vacuum inside a high temperature EMF cell in which higher and lower density liquid metal electrodes are separated by an intermediate density fused salt electrolyte. This innovation is in use on a sodium bismuth regenerable EMF cell in which the fused salts and metals are at about 500 deg to 600 deg C.
Cross linking in Styrene-Butadiene Rubber /SBR/ glass bead composites
Differential equations and numerical analysis for determining stress concentration and elastic deformation in rubber sheet under axially symmetric stretching
Stress concentration in rubber sheet under axially symmetric stretching, obtaining solutions through differential equations
Stress concentration in rubber sheet under axially symmetric stretching, obtaining solutions through differential equations
Crack tip stresses in rubber sheet determined by measuring strain field with imprinted grid work
Water is incorporated in a carrier and then thoroughly mixed with the single component silicone rubber containing acetic anhydride as a curing agent. Because curing occurs with the water supplied internally, controlled curing is possible within a reasonable period of time, regardless of the thickness of the material.
Reverted rubber during skidding of aircraft tires
Flame resistant silicone rubber using aluminum silicates and aromatic bromides
Atomic bond rupture rate in rubber subjected to uniaxial tensile strain in ozone environment monitored by electron paramagnetic resonance measurements
Molecular bond rupture and strain energy release rates correlation during ozone cracking of rubber from electron paramagnetic resonance and stress elongation measurements
Aerospace applications of elastomers are considered, including: propellant binders, bladder materials for liquid propellant expulsion systems, and fuel tank sealants for high-speed aircraft. A comprehensive molecular theory for mechanical properties of these materials has been developed but has only been tested experimentally in cases where chemical degradation processes are excluded. Hence, a study is being conducted to ascertain the nature, extent, and rate of chemical changes that take place in some elastomers of interest. Chemical changes that may take place in the fluorosilicone elastomer, LS 420, which is regarded as a fuel and high-temperature-resistant rubber are investigated. The kinetic analysis of the chemical stress relaxation and gel permeation chromatography studies comprise the major portion of the report.
Vacuum stability screening tests were performed on the Apollo 15 Scientific Instrument Module (SIM) bay nonmetallic materials in accordance with the NASA document SP-R-0022. The testing was necessary to support the evaluation to determine the effect material outgassing contamination would have on the SIM bay optical lenses and sensing devices. The Apollo 15 SIM experiments were highly successful, therefore, it is assumed that contamination due to the outgassing of nonmetallic materials did not affect equipment operation. A related problem, the reversion of a silicone rubber grommet which affected an electrical motor switch operation is also reported.