| Ultrasonic Inspection of Titan IV Stage I Baffles |
01 MAR 96 |
14 pages |
| Authors:
J. P. Nokes; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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 | The first-stage Titan Iv engine employs a set of seven CRES 347 stainless-steel baffles mounted to the injector for protection against combustion instabilities. Recent baffle design changes resulted in the failure of several baffles during engine acceptance testing. These failures generated concerns about the structural integrity of the new baffle design, which was employed in the construction of a number of engines, including those of the Titan Iv K-23 vehicle, ... |
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| Absorption of Water and Lubricating Oils Into Porous Nylon |
10 JAN 95 |
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| Authors:
P. A. Bertrand; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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 | Oil and water absorption from an into sintered porous nylon can be described by infiltration into the pores of the material. This process can be modeled by a diffusion-like mechanism. For water absorption, we find formal diffusion coefficient of 1.5 x 10(exp-4) sq cm/min when the nylon is initially dry. The diffusion coefficient is 4 x 10(exp-6) sq cm/min when the nylon is oil- impregnated prior to an exposure. In ... |
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| Processing and Heat Treatment Effects on an Al2O3/Ni3Al Composite. |
1994 |
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| Authors:
P. C. Brennan; W. H. Kao; J. M. Yang; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| This paper concerned mmc in some important way and contained information about, utilized, or discussed these subjects: basic topics:, data, imc, imc data materials and material types:, (al2o3)p/ni3al, al2o3 particulates, al2o3/ni3al, ic 221 matrix (see also ic-221 matrix), ic-221 matrix, ni3al matrix, particulates material characteristics and data fields:, bending strength, creep rate, yield strength data parameter values relevant to the data:, 1000 c - 1100 c, 1100 c - 1200 ... |
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| Performance of Silvered Teflon Thermal Control Blankets on Spacecraft |
15 MAR 93 |
15 pages |
| Authors:
G. Pippin; W. K. Stuckey; C. S. Hemminger; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| Silver-backed fluorinated ethylene propylene Teflon (Ag/FEP) thin film material was used for thermal control in many locations on the Long Duration Exposure Facility (LDEF). The Ag/FEP registered the effects of atomic oxygen, solar ultraviolet radiation, meteoroid and debris impacts, thermal cycling, and contamination. This report summarizes the post-flight condition of the Ag/FEP, compares the results with performance on other spacecraft, and presents lifetime estimates for use under a variety of ... |
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| Thermal Control Paints on LDEF: Results of M0003 Sub-Experiment 18 |
15 JAN 93 |
27 pages |
| Authors:
Christopher H. Jaggers; Michael J. Meshjishnek; John M. Coggi; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| Several thermal control paints were flown on LDEF, including the white paints Chemglaze A276, S13GLO, and YB-71, and the black paint D-111. The effects of low earth orbit, which include those induced by UV radiation and atomic oxygen, varied significantly with each paint and its location on LDEF. For example, samples of Chemglaze A276 located on the trailing edge of LDEF darkened significantly due to UV-induced degradation of the paint's ... |
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| Carbon and Graphite Matrices in Carbon-Carbon Composites: An Overview of their Formation, Structure, and Properties |
23 OCT 92 |
41 pages |
| Authors:
Gerald S. Rellick; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| Carbon-carbon (C/C) composites, so called because they combine carbon-fiber reinforcement in an all-carbon matrix, can best be viewed as part of the broader category of carbon-fiber-based composites, all of which seek to utilize the light weight and exceptional strength and stiffness of carbon fibers. In C/C particularly, the structural benefits of carbon-fiber reinforcement are combined with the high-temperature capability of an all-carbon materials system, making C/C composites the material of ... |
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| Some Observations on Stress Graphitization in Carbon-Carbon Composites |
15 SEP 92 |
35 pages |
| Authors:
Rafael J. Zaldivar; Gerald S. Rellick; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| The in situ stress graphitization behavior of hard carbons in unidirectionally aligned carbon-carbon (C/C) composites was studied for three carbon fibers (PAN-based T-50, pitch-based PX7, and rayon-based WCA) and two carbon precursor resins (phenol-formaldehyde (SC1008), and polyarylacetylene (PAA), a high-char-yielding, low-shrinkage resin). Graphitization was followed by measurements of density, transverse thermal expansion, d-spacing by x-ray diffraction (XRD), and by scanning electron microscopy (SEM). In conjunction with xenon-ion etching, the SEM ... |
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| Carborane-Catalyzed Graphitization in Polyarylacetylene-Derived Carbon- Carbon Composites |
15 SEP 92 |
35 pages |
| Authors:
Rafael J. Zaldivar; Ross W. Kobayashi; Gerald S. Rellick; J.-m. Yang; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| Boron in the form of a carborane compound, C2B10H12, was used to catalytically graphitize a polyarylacetylene (PAA) resin, typically a nongraphitizing carbon, in bulk form and in a carbon-carbon (C/C) composite. In bulk form, significant graphitization was observed after heat treatment to 1800 deg C; complete graphitization was realized at 2400 deg C. Similar results were found for a PAA derived carbon matrix in a unidirectional C/C composite. The effect ... |
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| The Influence of Steel Surface Chemistry on the Bonding of Lubricant Films |
01 SEP 92 |
26 pages |
| Authors:
S. V. Didziulis; M. R. Hilton; P. D. Fleischauer; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| Virtually all moving mechanical assemblies on spacecraft contain steel components that must be effectively lubricated to ensure optimum performance and long life. This report details the surface chemical composition of 440C stainless steel and its interaction with two lubricant species: the solid lubricant MoS2 and the liquid lubricant extreme pressure (EP) additive, lead naphthenate (Pbnp). X-ray photoelectron spectroscopy (XPS) studies show that the 440C surface has a layered oxide structure ... |
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| The Influence of Steel Surface Chemistry on the Bonding of Lubricant Films |
01 SEP 92 |
26 pages |
| Authors:
S. V. Didziulis; M. R. Hilton; P. D. Fleischauer; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| Virtually all moving mechanical assemblies on spacecraft contain steel components that must be effectively lubricated to ensure optimum performance and long life. This report details the surface chemical composition of 440C stainless steel and its interaction with two lubricant species: the solid lubricant MoS2 and the liquid lubricant extreme pressure (EP) additive, lead naphthenate (Pbnp). X-ray photoelectron spectroscopy (XPS) studies show that the 440C surface has layered oxide structure following ... |
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| The Chemistry of the Extreme Pressure Lubricant Additive Lead Naphthenate on Steel Surfaces |
01 SEP 92 |
48 pages |
| Authors:
S. V. Didziulis; P. D. Fleischauer; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| The adsorption and chemical reactivity of the extreme pressure (EP) oil additive lead naphthenate (Pbnp) on steel surfaces is examined with X-ray photoelectron spectroscopy. In addition, the chemical compositions of AISI 440C and 52100 steel surfaces are studied as a function of sample cleaning treatment, including solvent cleaning, and treatments with acidic and basic solutions. At room temperature, Pbnp is shown to |
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| Surface Phonon Dispersion of MoS2 |
31 JUL 92 |
23 pages |
| Authors:
P. A. Bertrand; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| The dispersion of phonons on the (0001) surface of MoS2 was measured by high-resolution electron energy loss spectroscopy along both the and azimuths (i.e., r to K and r to M respectively). The surface phonons have lower energies than the corresponding bulk phonons, which indicates that the bonding interactions of the surface atoms are different from those of the bulk, even in a layer lattice compound. Since sputtered MOS2 lubricant ... |
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| Structural and Tribological Studies of MoS sub 2 Solid Lubricant Films Having Tailored Metal-Multilayer Nanostructures |
15 DEC 91 |
36 pages |
| Authors:
M. R. Hilton; R. Bauer; S. V. Didziulis; M. T. Dugger; J. M. Keem; AEROSPACE CORP EL SEGUNDO CA MECHANICS AND MATERIALS TECHNOLOGY CENTER
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| Molybdenum disulfide (MoS2) solid lubricant films were prepared by rf magnetron sputtering on 440C steel, 52100 steel, and Si substrates. This study concentrated on films that were multilayer coatings of MoS2 with either Ni or Au-Pd(20%) metal interlayers. Multilayer thickness ranged from 0.2 nm to 1.0 run while the multilayer periodic spacing ranged from 3 to 10 nm. Scanning electron microscopy and X-ray diffraction revealed that the multilayer films had ... |
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Reports by Corporate Author
