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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Metallurgy: A compilation

A compilation on the technical uses of various metallurgical processes is presented. Descriptions are given of the mechanical properties of various alloys, ranging from TAZ-813 at 2200 F to investment cast alloy 718 at -320 F. Methods are also described for analyzing some of the constituents of various alloys from optical properties of carbide precipitates in Rene 41 to X-ray spectrographic analysis of the manganese content of high chromium steels.

Source record↗
NASA NTRS1972

Hair radioactivity as a measure of exposure to radioisotopes

Since many radioisotopes accumulate in hair, this tropism was investigated by comparing the radioactivity of shaved with plucked hair collected from rats at various time intervals up to 24 hrs after intravenous injection of the ecologically important radioisotopes, iodine-131, manganese-54, strontium-85, and zinc-65. The plucked hair includes the hair follicles where biochemical transformations are taking place. The data indicate a slight surge of each radioisotpe into the hair immediately after injection, a variation of content of each radionuclide in the hair, and a greater accumulation of radioactivity in plucked than in shaved hair. These results have application not only to hair as a measure of exposure to radioisotopes, but also to tissue damage and repair at the hair follicle.

Strain, W. H.↗
NASA NTRS1972

Dynamic holographic storage in lithium niobate

A program was undertaken to improve the optical recording properties of LiNbO3 for holographic optical memory application. Iron, copper, and manganese doping were all found to increase the optical sensitivity of LiNbO3. Over two orders of magnitude improvement was obtained, resulting in an exposure of 366 wirojoule/sq mm to obtain 1% efficiency in LiNbO3:Fe. High :Fe. High quality pictorial information was stored in 1mm diameter holograms.

Aronson, H.↗
NASA NTRS1972

Ultraviolet and charged particle irradiation of proposed solar cell coverslide materials and conductive coatings for the Helios spacecraft

Coverslide materials consisting of Corning 7940 fused silica, multilayers of titanium and manganese oxides (blue reflector), and indium oxide (conductive-coating) were exposed to 16 UVSC up to 800 EUVSH in vacuum. Slight changes in optical transmittance and optical absorptance were found in the (200-360) millimicron regions of the fused silica and conductive coating respectively. Exposure to 4 KeV protons and 4.5 KeV electrons in vacuum, produced decreases of several percent in transmittance, (200-360) millimicron region in the fused silicas after total fluxes less or = 10 to the 14th power particles/sq cm. Sheet resistance of the conductive coating increased above 1.0 kilo-ohm/square after a total flux less or = 10 to the 14th power particles/sq cm. Solar cells with coverglasses utilizing the indium oxide conductive coating were exposed to 1 Mev electrons and 1 Mev protons in air and in vacuum. Total fluxes ranged from 10 to the 11th power particles/sq cm to 10 to the 15th power particle/sq cm. There was no appreciable degradation in the resistance of the conductive coating during or after these tests.

Fry, J.↗
NASA NTRS1973

Development of high-emittance scales on thoriated nickel-chromium-aluminum-base alloys

The surface regions of a DSNiCrAl alloy have been doped, by a pack diffusion process, with small amounts of Mn, Fe, or Co, and the effect of these dopants on the total normal emissivity of the scales produced by subsequent high temperature oxidation has been measured. While all three elements lead to a modest increase in emissivity, (up to 23% greater than the undoped alloy) only the change caused by manganese is thermally stable. However, this increased emissivity is within 85 percent of that of TDNiCr oxidized to form a chromia scale. The maganese-doped alloy is some 50 percent weaker than undoped DSNiCrAl after the doping treatment, and approximately 30 percent weaker after oxidation.

Seltzer, M. S.↗
NASA NTRS1973

Solute effects on deformation and fracture of beta brass

It is shown that the ductility of several ternary beta brass alloys in air and in several liquid metals can be related to the operative slip and grain boundary relaxation processes. Nickel and manganese were chosen as alloying elements because they are expected to respectively enhance and suppress cross slip in beta brass. Single-phase binary and ternary beta brass alloys were used in both polycrystalline and single crystal form.

Shea, M. M.↗
NASA NTRS1974

An investigation of the plastic fracture of AISI 4340 and 18 nickel - 200 grade maraging steels

The mechanisms of plastic fracture (dimpled rupture) in high-purity and commercial 18 Ni, 200 grade maraging steels and quenched and tempered AISI 4340 steels have been studied. Plastic fracture takes place in the maraging alloys through void initiation by fracture of titanium carbo-nitride inclusions and the growth of these voids until impingement results in coalescence and final fracture. The fracture of AISI 4340 steel at a yield strength of 200 ksi occurs by nucleation and subsequent growth of voids formed by fracture of the interface between manganese sulfide inclusions and the matrix. The growth of these inclusion-nucleated voids is interrupted long before coalescence by impingement, by the formation of void sheets which connect neighboring sulfide-nucleated voids.

Cox, T. B.↗
NASA NTRS1975

Na-22, Ne-E, extinct radioactive anomalies and unsupported Ar-40

The possibility that the origin of extinct radioactivities depended on their living long enough for grains to form in the expanding nucleosynthetic envelope, rather than on their living long enough for meteorites to form, is examined. As an example, the interpretation of Na-22 as a detectable extinct radioactivity, with a half life of only 2.6 years, is explored and related to Ne-22 occurrence. Similar arguments involving He-4, Ar-40, K-40, K-41, and calcium, titanium, chromium, manganese, iron, nickel, and cobalt isotopes are briefly presented.

Clayton, D. D.↗
NASA NTRS1976

Zero-G processing of magnets experiment MA-070

Solidification of magnetic materials in the low gravity orbital environment was studied. The magnetic compounds under study, manganese bismuth and copper cobalt cerium ((Cu, Co)5Ce), both have the potential for the development of high coercive strength. Preliminary results indicate that static fluid configurations, in the absence of the gravitational body force, differ substantially from the documented terrestrial behavior. Chemical homogeneity is substantially enhanced on a macroscopic and microscopic level. Single crystal matrices have been grown in the coordinated growth regions of the flight samples. Primary crystals one order of magnitude greater than those grown terrestrially have been noted and are limited in size by the ampoule dimensions.

Larson, D. J., Jr.↗
NASA NTRS1978

Mechanical properties of low-nickel stainless steel

Demand for improved corrosion-resistant steels, coupled with increased emphasis on conserving strategic metals, has led to development of family of stainless steels in which manganese and nitrogen are substituted for portion of usual nickel content. Advantages are approximately-doubled yield strength in annealed condition, better resistance to stress-corrosion cracking, retention of low magnetic permeability even after severe cold working, excellent strength and ductility at cryogenic temperatures, superior resistance to wear and galling, and excellent high-temperature properties.

Montano, J. W.↗
NASA NTRS1977

Volatilization of oxides during oxidation of some superalloys at 1200 C

Volatilization of oxides during cyclic oxidation of commercial Nichrome, Inconel 750, Rene 41, Stellite 6B, and GE-1541 was studied at 1200 C in static air. Quantitative analysis of oxide vapor deposits revealed that oxides of tungsten, molybdenum, niobium, manganese, and chromium volatilized preferentially from the oxide scales. Aluminum and silicon were not detected in vapor deposits. For all the alloys except GE-1541, chromium was found to be the main metallic element in the oxide scales.

Zaplatynsky, I.↗
NASA NTRS1977

Friction and wear of single-crystal and polycrystalline maganese-zinc ferrite in contact with various metals

Sliding friction experiments were conducted with single-crystal (SCF) and hot-pressed polycrystalline (HPF) manganese-zinc ferrite in contact with various metals. Results indicate that the coefficients of friction for SCF and HPF are related to the relative chemical activity of those metals in high vacuum. The more active the metal, the higher the coefficient of friction. The coefficients of friction for both SCF and HPF were the same and much higher in vacuum than in argon at atmospheric pressure. All the metals tested transferred to the surface of both SCF and HPF in sliding. Both SCF and HPF exhibited cracking and fracture with sliding. Cracking in SCF is dependent on crystallographic characteristics. In HPF, cracking depends on the orientation of the individual crystallites.

Miyoshi, K.↗
NASA NTRS1977

The effect of temperature and pressure on the distribution of iron group elements between metal and olivine phases in the process of differentiation of protoplanetary material

The distribution patterns of Ni, Co, Mn, and Cr were studied in olivines of various origins: from meteorites (chondrites, achondrites, pallasites), which are likely analogs of the protoplanetary material, to peridotite inclusions in kimberlite pipes, which are analogs of mantle material. According to X-ray microanalysis data, nickel is concentrated in peridotite olivines, while manganese is concentrated in meteoritic olivines. The maximum chromium content was found in ureilites, which were formed under reducing conditions. Experiments at pressures of 20 to 70 kbar and temperatures of 1100 to 2000 C have shown that in a mixture of olivine and Ni metal or NiO, nickel enters the silicate phase, displacing Fe into the metallic phase. Equilibrium temperatures were estimated from the Fe, Ni distribution coefficients between the metal and olivine: 1500 K for pallasites, 1600 K for olivine-bronzite H6 chondrites, 1200 K for olivine-hypersthene L6, 900 K for LL6, and 1900 K for ureilites (at P = 1 atm). The equilibrium conditions of peridotites are close to T = 1800 K and P over 100 kbar. It is concluded that there is a sharp difference between the conditions of differentiation of the protoplanetary material at the time meteorites were formed and the conditions of differentiation of the planets into concentric layers.

Vinogradov, A. P.↗