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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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At least 595 records · Page 33
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NASA NTRS1972

Emission polarization study on quartz and calcite.

Calculation of the spectral emission polarization of quartz and calcite polished plates for observation angles of 20 and 70 deg by the substitution of complex index of refraction values for each mineral into Fresnel's equations. The emission polarization is shown to be quite wavelength-dependent, demonstrating that selected narrow or medium-width spectral bands exhibit a significantly higher percentage of polarization than a broad spectral band for these two minerals. Field measurements with a broadband infrared radiometer yield polarizations on the order of 2% for a coarse-grained granite rock and beach sand (both quartz-rich). This implies that a more sensitive detector with a selected medium-width filter may be capable of measuring emission polarization accurately enough to make this parameter useful as a remote sensing tool for discrimination among rocks on the basis of texture.

Vincent, R. K.↗
NASA NTRS1972

Chemical Processing Manual

Chemical processes presented in this document include cleaning, pickling, surface finishes, chemical milling, plating, dry film lubricants, and polishing. All types of chemical processes applicable to aluminum, for example, are to be found in the aluminum alloy section. There is a separate section for each category of metallic alloy plus a section for non-metals, such as plastics. The refractories, super-alloys and titanium, are prime candidates for the space shuttle, therefore, the chemical processes applicable to these alloys are contained in individual sections of this manual.

Beyerle, F. J.↗
NASA NTRS1972

Optical Production and Detection of Ultrasonic Waves in Metals for Nondestructive Testing

Ultrasonic waves were produced by striking the surface of a metal with the focused one-joule pulse of a Q-switched ruby laser. Rayleigh (surface) waves and longitudinal waves were detected with conventional transducers. Optical methods of detection were tested and developed. Rayleigh waves were produced with an oscillator and transducer. They were optically detected on curved polished surfaces, and on unpolished surfaces. The technique uses a knife edge to detect small angle changes of the surface as the wave pulse passes the illuminated spot. Optical flaw detection using pulse echo and attenuation is demonstrated.

Morrison, R. A.↗
NASA NTRS1973

An improved diffusion welding technique for TD-NiCr

An improved diffusion welding technique has been developed for TD-NiCr sheet. In the most preferred form, the improved technique consists of diffusion welding 320-grit sanded plus chemically polished surfaces of unrecrystallized TD-NiCr at 760 C under 140 MN/m2 pressure for 1hr followed by postheating at 1180 C for 2hr. Compared to previous work, this improved technique has the advantages of shorter welding time, lower welding temperature, lower welding pressure, and a simpler and more reproducible surface preparation procedure. Weldments were made that had parent-metal creep-rupture shear strength at 1100 C.

Holko, K. H.↗
NASA NTRS1973

Influence of various surface pretreatments on adherence of sputtered molybdenum disulfide to silver, gold, copper, and bronze

Solid film lubricants of radio frequency sputtered molybdenum disulfide (MoS2) were applied to silver, gold, copper, and bronze surfaces that had various pretreatments (mechanical polishing, sputter etching, oxidation, and sulfurization). Optical and electron transmission micrographs and electron diffraction patterns were used to interpret the film formation characteristics and to evaluate the sputtering conditions in regard to the film and substrate compatibility. Sputtered MoS2 films flaked and peeled on silver, copper, and bronze surfaces except when the surfaces had been specially oxidized. The flaking and peeling was a result of sulfide compound formation and the corresponding grain growth of the sulfide film. Sputtered MoS2 films showed no peeling and flaking on gold surfaces regardless of surface pretreatment.

Spalvins, T.↗
NASA NTRS1973

An exploratory study of the microstructure of mullite fibers

Mullite fibers of three compositions, ranging from SiO2-rich to Al2O3-rich, were investigated by a number of transmission electron microscopy (TEM) techniques. The fibers were examined in the as-received condition and after subjecting them to thermal exposures as high as 142 C. The investigative techniques used included direct TEM of microtomed sections of mounted fibers and TEM of replicas of polished, chemically etched, and cathodically etched fibers. In addition, X-ray diffraction line broadening analyses was used for determining average crystallite size. A preliminary description of the microstructure of mullite fibers is given.

Santoro, G. J.↗
NASA NTRS1972

LOXT mirror design study

The final report for the large orbiting X-ray telescope (LOXT) high resolution mirror design study is presented. The following tasks were performed: (1) Generation of a reference and alternate preliminary design for the LOXT high resolution mirror assembly, which will meet the LOXT scientific requirements, and are within the present state of the art of materials and fabrication techniques. (2) Measurement, in X-rays, of the scattering properties of a variety of optical flats, embodying materials, coatings, and polishing techniques which might be applicable to the flight configuration LOXT high resolution mirror. (3) Preparation of a procurement specification for a paraboloid test mirror of the size of the innermost paraboloid of the high resolution mirror assembly, including the design requirements for the reference design evolved from this preliminary design study. The results of the engineering and scientific analysis and the conclusions drawn are presented. The procurement specification for the test mirror is included.

Vanspeybroeck, L.↗
NASA NTRS1973

Performance evaluation of a strapdown electrically suspended gyro for space

The engineering development directed to improvement in strapdown electrically suspended gyro (SD/ESG) readout accuracy are described. The results of this development effort were represented by new and modified parts which were assembled into a strapdown ESG which was evaluated in terms of its readout system accuracy. The program performance goal was the demonstration of gyro readout to an accuracy of 15 arc-seconds or better. The results of calibrating over two sets of data were error amounts of 11.4 and 12.7 arc-seconds rms. The rms values of readout error were 12.7 and 13.8 arc-seconds for two sets of data not included in the calibration. The techniques for rotor preparation which were investigated under this contract included the application of a thin metal coating to the rotor surface in addition to the use of bare, polished beryllium rotors. Patterning application means which were utilized included a laser for pattern exposure of a photoresist coating and a grit-blast patterning machine which applied the pattern directly onto the metal surface of the rotor.

Elwell, D. F.↗
NASA NTRS1973

High resolution studies of the solar X-ray corona from Aerobee rockets

The research in high resolution solar X-ray astronomy is reported. The payload for the Aerobee 150 launch vehicle, which included a 23 cm diameter mirror whose polished surface was a nickel-phosphorus alloy is discussed along with the high resolution measurements, by Flight 13.028 CS, of the temperature and density structure of the lower corona. Flight 13.029 CS is also discussed.

Davis, J. M.↗
NASA NTRS1973

Enhanced diffusion welding

Surfaces of unrecrystallized alloys are sanded and polished. This is followed by a two-step welding process by which the strength of the parent metal is retained at the weld joint. The first step forces the surfaces into intimate contact at a temperature where the metal still has good ductility. The second step causes diffusion, recrystallization, and grain growth across the original weld interface.

Holko, K. H.↗
NASA NTRS1972

Meteoroid activity on the lunar surface from the Surveyor 3 sample examination.

The Surveyor 3 television camera shroud and polished aluminum tube, retrieved as a result of the Apollo 12 mission after 2.5 years on the lunar surface, were examined for evidence of meteoroid impact. Resulting estimates of the meteoroid flux in the lunar vicinity are shown to be in good agreement with the Lunar Orbiter penetration rates. In addition, the relationship between a derived lunar-surface meteoroid cumulative-flux model and the comparable near-earth model is discussed in the light of theoretical predictions. It is shown that the effect of the gravitational field of the earth on the near-earth environment was greater than previously predicted.

Cour-Palais, B. G.↗
NASA NTRS1972

Pyroxenes from breccia 14303.

Review of the investigation results obtained on the adjacent polished thin sections 47 and 53 of breccia 14303, the largest rock returned by Apollo 14 for which a location has not been established. A basaltic lithic clast, composed mainly of plagioclase, olivine, and pigeonite zoned to subcalcic augite, is found to occupy the same relative position in both sections and is assumed to represent a single lithic chip. Further study of lithic and fragmental clasts in breccias is seen likely to yield information on lunar history between 4.6 and 3.9 b.y. ago.

Weigand, P. W.↗
NASA NTRS1972

Rock 14068 - An unusual lunar breccia.

Rock 14068 is a walnut-sized clast of dark breccia from station C1 near Cone Crater. The rock's dominant component is an olivine-rich groundmass. Petrographic and chemical studies were made of polished sections of the rock. The origin of the material is discussed. It is thought possible that the melt was produced by remelting a preexisting lunar rock of the same composition. Another possibility considered is that the rock composition constitutes a mixture of several rock types of partly meteoritic origin.

Helz, R. T.↗
NASA NTRS1973

Shock history of mesosiderites.

The (still largely incomplete) shock histories of 18 stony-iron meteorites (classified as mesosiderites) are studied. The crystallographic character of kamacite in each (polished and etched) sample was determined by a back-reflection X-ray diffraction technique. All specimens were studied metallographically, and some by reflected light microscopy. The shock history of each sample is determined in kbar.

Jain, A. V.↗
NASA NTRS1973

Petrology of some lithic fragments from Luna 20.

Microscopic and electron microprobe studies were made of polished thin sections of part of a 30-mg sample of 250- to 500-micron lunar soil returned by Luna 20 from a point between Mare Fecunditatis and Mare Crisium. Very fine-grained lithic (crystalline) rock fragments, composing about one-fifth of the total sample, have mineralogical compositions equivalent to various types of gabbro, anorthositic gabbro, gabbroic anorthosite, and troctolite, with minor basalt. The textures now observed in these fragments are in large part metamorphic. Twenty-seven electron microprobe analyses of minerals from these fragments are presented, including olivine, plagioclase, pyroxene, spinel, nickel-iron, and a Zr-Ti-REE mineral possibly similar to 'phase B' of Lovering and Wark (1971). Analyses of seven melt inclusions and 28 defocused beam analyses of lithic fragments are also given. Some of the fragments contain 'gas' inclusions which, along with the fine grain size, are believed to indicate final crystallization under low pressure near surface conditions.

Roedder, E.↗
NASA NTRS1973

Optical stability of coatings exposed to four years space environment on OSO-III.

The Thermal Control Coatings Experiment flown on OSO 3 in the near-earth space environment was designed to measure changes in the solar absorptance and IR emittance of selected test coatings. The present work describes results obtained from four years in orbit. Changes in solar absorptance of the coatings are illustrated as a function of equivalent sun hours, and it is seen that five of eleven coatings considered exhibit no change in solar absorptance over four years or 7500 equivalent sun hours. The effects of micrometeoroids on polished metal surfaces are judged to be negligible for a near-earth mission of four years.

Millard, J. P.↗
NASA NTRS1973

Ventifact evolution in Wright Valley, Antarctica.

Ventifacts occurring on extensive wind-deflated surfaces throughout the ice-free Wright Valley are the product of complex evolutionary processes. The wind produces a lag gravel which continues to evolve at a reduced rate as coarser granule and gravel fractions are removed. The morphology of ventifacts forming the lag gravels suggests that the distribution of wind-polished faces is determined largely by the shape of the original unpolished rock fragments. In the early stages ventifacts tend to be oriented either transverse or parallel to the wind direction. Salt weathering is also a major factor in determining the morphology of the Wright Valley ventifacts.

Lindsay, J. F.↗
NASA NTRS1973

Emittance measurement of Surveyor 3 material.

Calorimetric measurements of the total hemispherical emittance of a section of polished aluminum support tubing from the Surveyor 3 spacecraft are reported. The values found, 0.090 at 25 C and 0.089 at 50 C, are lower than was expected from a visual estimate but are in good agreement with an estimate based upon scanning electron microscopy of the tubing.

Dahms, R. G.↗