Search NASA⌕ Search

SEARCH · Search NASA

Results for “Abrasion Resistance”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Wide temperature range fiber optic cable: Cable design study

Factors considered in the design and fabrication of a single fiber optic cable intended for spacecraft applications in an environment of temperature extremes from -160 C to 125 C include: abrasion resistance, low temperature flexibility, small size, low weight, and overall temperature stability. Specific requirements were identified for fiber core and overall diameters, fiber loss and NA, and cable tensile load. The single fiber cable will be fabricated by using a chemical vapor step index fiber of .125 mm coated to .3 mm with RTV silicone and then extruded with a jacket of Teflon PFA to a diameter of .5 mm. Six yarns of 1420 denier unimpregnated Kevlar 49 with a helical lay of 1.3 inches will surround the jacketed fiber under an extrusion of PFA. The finished cable diameter will measure 1.8 mm, and the weight of one kilometer length will be approximately 4350grams.

Speed, E. U.↗
NASA NTRS1980

Recirculating sprayer for fiber-filled paints

Recirculating paint sprayer applies spray of coarse filler in highly volatile solvent. Sprayer was developed for applying insulation material containing epxoy resin, glass fibers, and inert fillers suspended in chlorinated solvents. Sprayer resists abrasive action of fiberglass filler and chemical activity of solvent. Pump and position ensure more uniform pressure at spray gun without backpressure regulator, which tended to clog in old sprayer.

Major, R. K.↗
NASA NTRS1978

Testing and environmental exposure of parachute materials for the solid rocket booster decelerator subsystem

Static tests and evaluation of nonmetallic materials for use in parachutes for recovery of solid rocket boosters used in the space shuttle program are reported. Literature survey and manufacturer and vendor contacts led to the choice of nylon as the fabric most capable of withstanding the extreme loads and environmental conditions during repeated use. The material tests included rupture strength, elongation, abrasion resistance, shrinkage, environmental exposure, and degradation levels. Rinsing and drying procedures were also investigated and a salt-free level for nylon recommended in preparation for reuse. In all possible cases, worst-case conditions were used (e.g., inflation loads, seawater exposure for 3 days per drop-recovery, etc.).

Tannehill, B. K.↗
NASA NTRS1981

Chlorinolysis reclaims rubber of waste tires

Process reclaims rubber and reduces sulfur content by using chlorine gas to oxidize sulfur bonds in preference to other bonds. Rubber does not have poor hysteresis and abrasion resistance like conventionally reclaimed rubber and is suitable for premium radial tires. Chlorinated rubber is less susceptible to swelling by oils and may be used as paint ingredient.

Dufresne, E. R.↗
NASA NTRS1982

Flame-Retardant Coating is Heat-Sealed

Plastic coating that makes fabrics flame-and abrasion-resistant is sealed to fabric by heat. Coating produces flexible, lightweight, impermeable fabrics that are firesafe and can withstand rough use. Coated fabric was developed for use in garments and containers for space exploration, but would also be suitable for rainwear, clothing for hazardous environments, and leakproof containers.

Tschirch, R. P.↗
NASA NTRS1983

Development of Silane Hydrolysate Binder for Thermal-Control Coatings

Technical report describes theoretical and experimental development of methyltriethoxysilane (MTES) hydrolysate binder for white, titanium dioxidepigmented thermal-control coatings often needed on satellites. New coating is tougher and more abrasion-resistant than conventional coating, S-13G, which comprises zinc oxide in hydroxyl-therminated dimethylsiloxane binder.

Patterson, W. J.↗
NASA NTRS1988

Carbon Coating Of Copper By Arc-Discharge Pyrolysis

Adherent, abrasion-resistant coat deposited with existing equipment. Carbon formed and deposited as coating on copper substrate by pyrolysis of hydrocarbon oil in electrical-arc discharges. Technique for producing carbon deposits on copper accomplished with electrical-discharge-machining equipment used for cutting metals. Applications for new coating technique include the following: solar-energy-collecting devices, coating of metals other than copper with carbon, and carburization of metal surfaces.

Ebihara, Ben T.↗
NASA NTRS1990

Aeolian removal of dust from photovoltaic surfaces on Mars

It is well documented that Mars is totally engulfed in huge dust storms nearly each Martian year. Dust elevated in these global dust storms, or in any of the numerous local dust storms could settle on photovoltaic surfaces and seriously hamper photovoltaic power system performance. Using a recently developed technique to uniformly dust simulated photovoltaic surfaces, samples were subjected to Martian-like winds in an attempt to determine whether natural aeolian processes on Mars would sweep off the settled dust. The effects of wind velocity, angle of attack, height off the Martian surface, and surface coating material were investigated. Principles which can help to guide the design of photovoltaic arrays bound for the Martian surface were uncovered. Most importantly, arrays mounted with an angle of attack approaching 45 deg show the most efficient clearing. Although the angular dependence is not sharp, horizontally mounted arrays required significantly higher wind velocities to clear off the dust. From the perspective of dust-clearing it appears that the arrays may be erected quite near the ground, but previous studies have suggested that saltation effects can be expected to cause such arrays to be covered by sand if they are set up less than about a meter from the ground. Providing that the surface chemistry of Martian dusts is comparable to our test dust, the materials used for protective coating may be optimized for other considerations such as transparency, and chemical or abrasion resistance. The static threshold velocity is low enough that there are regions on Mars which experience winds strong enough to clear off a photovoltaic array if it is properly oriented. Turbulence fences proved to be an ineffective strategy to keep dust cleared from the photovoltaic surfaces.

Gaier, James R.↗
NASA NTRS1991

Deposition Of Diamondlike Films By ECR Microwave Plasma

Hard, amorphous hydrogenated carbon films of diamondlike quality deposited at room temperature on silicon, optical glass, and quartz through decomposition of CH4 in electron-cyclotron-resonance (ECR) microwave plasma of CH4 diluted with H2. Technique provides hard, abrasion-resistant coatings for lenses and other optical components. Films chemically inert and posses high electrical resistivity and breakdown fields, valuable properties in microelectronics applications.

Pool, Frederick S.↗
NASA NTRS1991

Processing of glass-ceramics from lunar resources

The goal is to fabricate useful ceramic materials from the by-products of lunar oxygen production processes. Specifically, the crystal nucleation and growth kinetics of ilmenite-extracted lunar regolith were studied in order to produce glass-ceramics with optimal mechanical, thermal, and abrasion resistant properties. In the initial year of the program, construction and calibration of a high temperature viscometer, used for determining the viscosity of simulated lunar glasses was finished. A series of lunar simulants were also prepared, and the viscosity of each was determined over a range of temperatures. It was found that an increase in the concentration of Fe2O3 decreases the viscosity of the glass. While this may be helpful in processing the glass, Fe2O3 concentrations greater than approximately 10 wt percent resulted in uncontrolled crystallization during viscosity measurements. Impurities (such as Na2O, MnO, and K2O) in the regolith appeared to decrease the viscosity of the parent glass. These effects, as well as those of TiO2 and SiO2 on the processability of the glass, however, remain to be quantified.

Fabes, B. D.↗
NASA NTRS1992

High temperature dynamic engine seal technology development

Combined cycle ramjet/scramjet engines being designed for advanced hypersonic vehicles, including the National Aerospace Plane (NASP), require innovative high temperature dynamic seals to seal the sliding interfaces of the articulated engine panels. New seals are required that will operate hot (1200 to 2000 F), seal pressures ranging from 0 to 100 psi, remain flexible to accommodate significant sidewall distortions, and resist abrasion over the engine's operational life. This report reviews the recent high temperature durability screening assessments of a new braided rope seal concept, braided of emerging high temperature materials, that shows promise of meeting many of the seal demands of hypersonic engines. The paper presents durability data for: (1) the fundamental seal building blocks, a range of candidate ceramic fiber tows; and for (2) braided rope seal subelements scrubbed under engine simulated sliding, temperature, and preload conditions. Seal material/architecture attributes and limitations are identified through the investigations performed. The paper summarizes the current seal technology development status and presents areas in which future work will be performed.

Steinetz, Bruce M.↗
NASA NTRS1993

High-Temperature, Flexible, Fiber-Preform Seals

High-temperature, flexible, fiber-preform seal includes axial core and helical windings, and abrasion-resistant sheath. Seals tailored to service in variety of environments. Used between movable and stationary panels in advanced aircraft engines or to seal gaps of high-temperature furnaces.

Steinetz, Bruce M.↗
NASA NTRS1992

Glasses, ceramics, and composites from lunar materials

A variety of useful silicate materials can be synthesized from lunar rocks and soils. The simplest to manufacture are glasses and glass-ceramics. Glass fibers can be drawn from a variety of basaltic glasses. Glass articles formed from titania-rich basalts are capable of fine-grained internal crystallization, with resulting strength and abrasion resistance allowing their wide application in construction. Specialty glass-ceramics and fiber-reinforced composites would rely on chemical separation of magnesium silicates and aluminosilicates as well as oxides titania and alumina. Polycrystalline enstatite with induced lamellar twinning has high fracture toughness, while cordierite glass-ceramics combine excellent thermal shock resistance with high flexural strengths. If sapphire or rutile whiskers can be made, composites of even better mechanical properties are envisioned.

Beall, George H.↗
NASA NTRS1993

Flexible storage medium for write-once optical tape

A write-once data storage media was developed which is suitable for optical tape applications. The media is manufactured using a continuous film process to deposit a ternary alloy of tin, bismuth, and copper. This laser sensitive layer is sputter deposited onto commercial plastic web as a single-layer thin film. A second layer is sequentially deposited on top of the alloy to enhance the media performance and act as an abrasion resistant hard overcoat. The media was observed to have laser write sensitivities of less than 2.0 njoules/bit, carrier-to-noise levels of greater than 50dB's, modulation depths of approximately 100 percent, read-margins of greater than 35, uniform grain sizes of less than 200 Angstroms, and a media lifetime that exceeds 10 years. Prototype tape media was produced for use in the CREO drive system. The active and overcoat materials are first sputter deposited onto three mil PET film in a single pass through the vacuum coating system, and then converted down into multiple reels of 35mm x 880m tape. One mil PET film was also coated in this manner and then slit and packaged into 3480 tape cartridges.

Strandjord, Andrew J. G.↗
NASA NTRS1994

High-Temperature, Bellows Hybrid Seal

A high-temperature hybrid seal is constructed of multiple elements to meet the many demands placed on the seal. The primary elements are: a central high-temperature bellows, a braided ceramic sheath covering the bellows, an outer abrasion resistant sheath covering the ceramic sheath, and a structurally-sound seal-end termination.

Steinetz, Bruce M.↗
NASA NTRS1994

Evaluation of Wiring Constructions for Space Applications

A NASA Office of Safety and Mission Assurance (OS&MA) program to develop lightweight, reliable, and safe wiring insulations for aerospace applications is being performed by the NASA Lewis Research Center (LeRC). As part of this effort, a new wiring construction utilizing high strength PTFE (poly tetrafluoroethylene) as the insulation has been tested and compared with the existing military standard polyimide-based MIL-W-81381 wire construction. Electrical properties which were investigated included ac corona inception and extinction voltages (sea level and 60,000 feet), time/current to smoke, and wire fusing time. The two constructions were also characterized in terms of their mechanical properties of flexural strength, abrasion resistance (23 C and 150 C), and dynamic cut-through (23 C and 200 C). The results obtained in this testing effort are presented and discussed in this paper.

Hammoud, Ahmad N.↗