| Compatibility of Tantalum Columbium, and Their Alloys with Hydrogen in Presence of Temperature Gradient |
AUG 1966 |
26 pages |
| Authors:
Joseph R. Stephens; Ralph G. Garlick; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
 | An investigation on the compatibility of tantalum and columbium with hydrogen in the presence of a temperature gradient was conducted to determine the suitability of these materials for use in a hydrogen-cooled nuclear rocket nozzle. Specimens having a temperature gradient from room temperature to approximately 30000 F were heated in a hydrogen atmosphere, held for a predetermined time, and cooled in hydrogen at rates from 250 to 15000 F per ... |
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| Design and Cooling Performance of a Dump-Cooled Rocket Engine |
AUG 1966 |
48 pages |
| Authors:
Albert J. Pavli; Jerome K. Curley; Philip A. Masters; R. M. Schwartz; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| A dump-cooled engine was designed and experimentally evaluated as a 500-pound- thrust rocket engine operating at 100-psig chamber pressure with gaseous hydrogen and liquid oxygen as propellants and liquid hydrogen as a coolant. Fourteen firings were made; of these, the last four were with a refractory coating of aluminum oxide on the flame-side surface. Data showing the measured and analytical heat fluxes along with coolant temperatures and pressures through the ... |
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| Cold Reduction As a Means of Reducing Embrittlement of a Cobalt-Base Alloy (L-605), |
AUG 1966 |
|
| Authors:
G. D. Sandrock; L. Leonard; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Effect of Alloying on Grain Refinement of Electron-Beam-Melted Tungsten |
JUL 1966 |
20 pages |
| Authors:
Walter R. Witzke; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Ingot structures resulting from electron-beam melting of tungsten consist mainly of columnar grains extending the length of the ingot. In order to examine the grain refining capabilities of various elemental and refractory compound additions, small ingots of tungsten containing these additions were prepared by electron-beam melting. Measurements on transverse ingot sections from each melt indicated that all the additions decreased the average grain diameter of the columnar grains typical of ... |
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| Analysis of Performance of Double-Reflector System for Collecting Solar Energy |
JUL 1966 |
30 pages |
| Authors:
Gabriel Kaykaty; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| A double-reflector system for collecting solar energy was analyzed with regard to its performance to provide an appraisal of its applicability to a solar Brayton cycle Power system. The maximum efficiency expected under the most favorable conditions was predicted and compared with that of a collection system consisting of a single paraboloid with the receiver aperture at the focus. The double-reflector collection system which was surveyed employed a paraboloid for ... |
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| Effect of Orientation on Friction Characteristics of Single-Crystal Beryllium in Vacuum (10(exp -10) Torr) |
JUL 1966 |
21 pages |
| Authors:
Donald H. Buckley; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Studies were conducted to determine the influences of the crystallographic orientation of single-crystal beryllium on its friction characteristics when in sliding contact with sapphire and polycrystalline beryllium and aluminum oxide. Experiments were conducted in a vacuum of 10(exp - 10) torr with a 3/16-inch hemispherical-radius beryllium crystal sliding on a flat of beryllium and aluminum oxide. The rider was loaded against the flat with various loads from 100 to 1500 ... |
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| Stress-Rupture Properties of Tungsten Wire from 1200 degree to 2500 degree F |
JUL 1966 |
23 pages |
| Authors:
David L. McDanels; Robert A. Signorelli; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The stress-rupture properties of 5-mil-diameter, type 218CS tungsten wire were determined for rupture times up to about 200 hours at test temperatures from 12000 to 25000 F. Results showed that the rupture properties were superior to those reported for other forms of tungsten, other refractory metals, and super alloys in this temperature range. The onset of primary recrystallization observed between 18000 and 20000 F was indicated by a decrease in ... |
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| Self-Lubricating Composites of Porous Nickel and Nickel-Chromium Alloy Impregnated with Barium Fluoride-Calcium Fluoride Eutectic |
JUL 1966 |
22 pages |
| Authors:
Harold E. Sliney; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Self-lubricating composites were prepared by vacuum-impregnating porous nickel or Inconel X-750 (nickel-chromium alloy) with a barium fluoride - calcium fluoride eutectic composition. Density measurements and photomicrographs of the resulting composite structures demonstrated that this process completely filled the voids of the porous metals with the fluoride eutectic. The compressive yield strength of the nickel composites was quite low (about 30 000 psi); therefore, in order to avoid severe plastic deformation ... |
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| Cold Consolidation of Metal Plus Dispersoid Blends for Examination by Electron Microscopy |
JUL 1966 |
37 pages |
| Authors:
Gustav Reinhardt; Walter S. Cremens; John W. Weeton; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
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| Dimple, Spall, and Perforation Characteristics in Aluminum, Columbium, and Steel Plates Under Hypervelocity Impact |
JUN 1966 |
21 pages |
| Authors:
Nestor Clough; A. R. McMillian; Seymour Lieblein; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| An experimental research program designed to determine the critical damage modes that might be inflicted on various armor materials by the impact of a high-velocity projectile was conducted. The experimental program was performed under NASA contract on a ballistics range facility of the General Motors Corporation, Defense Research Laboratories, Santa Barbara, California. |
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| Compatibility of Columbium and Tantalum Tubing Alloys with Refluxing Potassium |
MAY 1966 |
44 pages |
| Authors:
Coulson M. Scheuermann; Charles A. Barrett; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| This report summarized a proposed mechanism, based on experimental results, that describes the oxygen accelerated corrosive attack of columbium and columbium alloys by potassium under refluxing conditions, involving the formation and solution of complex oxides. This mechanism may be expected to be applicable, in principle, to the other refractory metal - alkali metal systems as well. Cases of gettered and ungettered alloys are considered. The various reaction products, their roles ... |
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| Accelerated Cavitation Damage of Steels and Superalloys in Liquid Metals |
MAY 1966 |
37 pages |
| Authors:
Stanely G. Young; James R. Johnston; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Evaluation of Special 301-Type Stainless Steel for Improved Low-Temperature Notch Toughness of Cryoformed Pressure Vessels, |
MAY 1966 |
|
| Authors:
T. W. Orange; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
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| Thermodynamic and Transport Properties for the N2O4 yields 2NO2 yields 2NO+O2 (reversible reaction) System |
MAR 1966 |
59 pages |
| Authors:
Roger A. Svebla; Richard S. Brokaw; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Thermodynamic and transport properties, including enthalpy, entropy, heat capacity, molecular weight, viscosity, and thermal conductivity, have been calculated for the N2O4 = 2NO2 equilibrium and also the N2O4 = 2NO2 = 2NO+O2 equilibrium from 300 to 1280 K and from 0.Ol to 100 atmospheres. The Prandtl number, Lewis number, isentropic exponent, and two derivatives involving the molecular weight, pressure, and temperature were also calculated. The Chapman- Enskog theory of monatomic ... |
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| Use of Carbon Dioxide to Calibrate Instrument for Determination of Carbon Below 50 Parts per Million in Metals |
MAR 1966 |
7 pages |
| Authors:
Emery J. Merkle; Judson W. Graab; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| In the determination of carbon below 50 parts per million organic compounds have been used for calibration in the absence of suitable metallic standards. The addition of gaseous carbon dioxide (CO2) as a calibration technique is proposed. A comparison of standardizations with an organic compound and with CO2 additions is presented. A significant improvement in the precision of a calibration curve by using CO2 is demonstrated. |
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| Fracture Mechanics of Through-Cracked Cylindrical Pressure Vessels |
FEB 1966 |
35 pages |
| Authors:
Robert B. Anderson; Timothy L. Sullivan; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The application of some fracture mechanics concepts to the prediction of the strength of pressure vessels in which cracks have penetrated entirely through the vessel wall is examined. The strength of cylindrical pressure vessels (with longitudinal through-cracks) is related to the geometry of the cylinder, the crack length, the material yield strength, and fracture toughness. An expression for the crack tip stress intensity factor is derived by considering the influence ... |
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| Stress-Intensity Factors by Boundary Collocation for Single-Edge-Notch Specimens Subject to Splitting Forces |
FEB 1966 |
13 pages |
| Authors:
Bernard Gross; John E. Srawley; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| A boundary -value-collocation procedure was applied in conjunction with the Williams stress function to determine values of the stress-intensity factor K1 for single-edge cracks in plate specimens subject to splitting forces applied close to the crack and acting transversely to it. The results are presented in terms of the dimensionless quantity Y = K1BH3 /2/pa, where B and H are the specimen thickness and half-depth, a is the effective crack ... |
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| Evaluation of Impregnated Lubricants in Ball-Bearing Retainers at 10-6 Torr |
FEB 1966 |
23 pages |
| Authors:
L. D. Smith; Dean C. Glenn; Herbert W. Scibbe; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Four liquid lubricants, a polyphenyl ether, a polysiloxane, a sebacate, and a high-viscosity mineral oil, were evaluated as lubricating impregnants in cotton-cloth phenolic retainers of 20-millimeter-bore ball bearings operating in a vacuum of 10-6 torr. The effect of the cloth weave on the lubricating effectiveness of the best of the lubricants was also studied. The test bearings were run at 3550 rpm under axial loads of 50 to 100 pounds ... |
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| Thermal Radiation Absorptance and Vacuum Outgassing Characteristics of Several Metallic and Coated Surfaces |
FEB 1966 |
59 pages |
| Authors:
Takuo Mimura; Evelyn Anagnostou; Paul E. Colarusso; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Mechanical Properties of Solid-Solution and Carbide-Strengthened Arc- Melted Tungsten Alloys |
FEB 1966 |
38 pages |
| Authors:
Peter L. Raffo; William D. Klopp; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Influence of Boron Additions on Physical and Mechanical Properties of Arc-Melted Tungsten and Tungsten-1 Percent Tantalum Alloy |
FEB 1966 |
23 pages |
| Authors:
Peter L. Raffo; William D. Klopp; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| The effects of boron additions on the physical and mechanical properties of arc-melted tungsten and a tungsten -1 percent tantalum alloy were investigated. Boron additions significantly refined the arc-melted grain size of tungsten. The 1-hour recrystallization temperature was initially increased by small boron additions (approx. 0.01 atomic percent boron), after which it decreased continuously with increasing boron content. High-temperature tensile tests showed that the boron additions produced an initial rapid ... |
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| The Erected Dipole Model in the Adsorption of Cesium on Fluorinated Molybdenum |
FEB 1966 |
31 pages |
| Authors:
Leonard K. Tower; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Interest in power-producing thermionic diodes containing both electropositive and electronegative additives has lead to studies of the structure of adsorbed layers. One of the models advanced to describe this layer is that of the erected dipole, in which polar molecules are erected on a surface by a strong surface electric field. Published evidence for this structure in the case of some adsorbates, namely, barium oxide and cesium chloride, is reviewed. ... |
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| Theoretical Elastic Mismatch Stresses |
JAN 1966 |
26 pages |
| Authors:
Robert H. Johns; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Stress- magnification factors were obtained for the effect of mismatch of the middle surfaces at junctions in shell structures. The results are directly applicable only when the thickness and the slope on one side of a mismatched joint are the same as those on the other. Results are found for biaxial stress states with any principal stress ratio at the joint, including cases in which the stresses are of opposite ... |
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| Experimental Data on Pumping of Mercury Ion Beams by Liquid-Nitrogen- Cooled Condensers |
JAN 1966 |
16 pages |
| Authors:
Edward A. Maslowski; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| A program was conducted to evaluate the performance of liquid- nitrogen-cooled condensers in pumping the exhaust of mercury ion thrustors. Tests were conducted with two different condensers. One of the condensers was a smooth cylinder having a total surface area of 3. 8 square meters, and the other condenser was of honeycomb type of construction and had a total surface area of 62. 9 square meters. Two targets, having apex ... |
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| Weight Study of Partially Segmented Direct-Condensing Radiators for Large Space Power Systems |
JAN 1966 |
52 pages |
| Authors:
Roy L. Johnsen; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| An analytical investigation has been performed to provide an insight into the weight increase of a direct-condensing radiator for a potassium Rankine cycle space power system as the system size was increased from 1 to 10 megawatts electric while holding constant the component efficiencies and all cycle temperatures and pressures. The largest single contributor to the radiator weight is the armor necessary to protect fluid passages from meteoroid puncture. The ... |
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| Friction, Wear, and Adhesion Characteristics of Titanium-Aluminum Alloys in Vacuum |
JAN 1966 |
19 pages |
| Authors:
Donald H. Buckley; Robert L. Johnson; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Friction, wear, and adhesion measurements were made in vacuum of titanium-aluminum alloys containing 11, 16, and 21 weight percent aluminum. Experiments were conducted with a 3/16 inch radius rider sliding on the flat surface of a 2.5 inch diameter disk specimen at loads to 1500 grams. The disk was rotated to produce sliding velocities to 750 centimeters per second. With increasing addition of aluminum to titanium, an increase in lattice ... |
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| Effect of Cold Reduction and Thermal Treatment on Tensile Properties of a Nickel - 2 Percent Beryllium Alloy at Cryogenic Temperatures |
JAN 1966 |
19 pages |
| Authors:
Thomas W. Orange; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| This investigation was conducted to determine the tensile properties of a precipitation-hardenable nickel -2 percent beryllium alloy (Berylco 440) in 0.020-inch-thick sheet form at temperatures from ambient to -423 degrees F. The properties of this alloy over the range of commercially available conditions were determined, and the effects of extended aging times and temperatures as well as degrees of cold reduction greater than those commercially available were studied. Specimens parallel ... |
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| Room-Temperature Tensile Behavior of Oriented Tungsten Single Crystals with Rhenium in Dilute Solid Solution |
JAN 1966 |
17 pages |
| Authors:
M. Garfinkle; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Tungsten single crystals oriented in the direction with rhenium contents from 0 to 9 atomic percent were deformed in tension at room temperature. The addition of rhenium drastically affected the tensile behavior of these crystals was determined. Rhenium additions increased the proportional limit stress and decreased both the flow stress and the rate of work hardening. In addition, discontinuous yielding and necking during deformation were observed in crystals containing ... |
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| Dynamic Instability of Undamped Bellows Face Seals in Cryogenic Liquid |
JAN 1966 |
21 pages |
| Authors:
John C. Hudelson; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The primary motions of an undamped bellows face seal are described along with the displacements and frequencies of the motions experienced during dynamic instability. Subminiature accelerometers were attached to the nosepiece of a 1 3/4-inch nominal shaft diameter bellows seal and the accelerations and frequencies recorded on magnetic tape for analysis at an expanded time factor. The results of the tests indicated that dynamic instability will occur in undamped bellows ... |
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| Feasibility of Accelerating Micron-Size Particles in Shock-Tube Flows for Hypervelocity Degradation of Reflective Surfaces |
JAN 1966 |
35 pages |
| Authors:
Michael J. Mirtich; Herman Mark; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Manned Mars Landing Missions Using Electric Propulsion |
JAN 1966 |
30 pages |
| Authors:
John S. MacKay; Charles L. Zola; Leonard G. Rossa; Laurence H. Fishbach; William C. Strack; Frank J. Hrach; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Static Aerodynamic Characteristics of a Rocket Vehicle with Thick Wedge Fins and Sweptback Leading and Trailing Edges |
JAN 1966 |
16 pages |
| Authors:
Joseph A. Yuska; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The longitudinal static stability characteristics of three one-fifth scale models of the second stage of a sounding rocket were calculated and compared with the measured values at Mach numbers of 1.79 to 3.47. All three models had fins of trapezoidal planform with sweptback leading and trailing edges, small aspect ratio, and thick wedge sections, but differed in fin area and overall model length. Calculation of center of pressure and normal-force ... |
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| Investigation of Hydrotest Failure of Thiokol Chemical Corporation 260-Inch-Diameter SL-1 Motor Case |
JAN 1966 |
85 pages |
| Authors:
John E. Srawley; Jack B. Esgar; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The Thiokol Chemical Corporation 260-inch-diameter SL-1 motor case failed during hydrotest at a pressure of 542 pounds per square inch, which was about 56 percent of proof pressure. The motor case was constructed of 250 grade maraging steel plate joined mostly by submerged arc automatic welding. An investigation of the failure was conducted by a Committee composed of members from Industry and Government. Investigation showed that the failure originated from ... |
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| Condensation Pressure Drop of Nonwetting Mercury in a Uniformly Tapered Tube in 1-g and Zero-Gravity Environments |
JAN 1966 |
41 pages |
| Authors:
James A. Albers; Robert P. Macosko; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Ultrahigh-Vacuum Creep Behavior of Columbium and Tantalum Alloys at 2000 degs and 2200 degs F for Times Greater Than 1000 Hours |
JAN 1966 |
27 pages |
| Authors:
Robert H. Titran; Robert W. Hall; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Creep tests of 1000 hours and greater were conducted at 2000 degrees and 2200 degrees F on six commercially available refractory alloys at pressures of 10 (exp -8) to 10 (exp -9) torr. The creep behavior of three columbium alloys, FS-85 (Cb + 28Ta + 10W + 1Zr), D-43, (Ch + 10W + 1Zr +0.1C), and Cb-752 (Cb +10W + 2.5Zr), and three tantalum alloys, T-222 (Ta + 9.6W + ... |
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| Electrical Resistivity and Conductivity of Tungsten-Fiber-Reinforced Copper Composites |
66 |
|
| Authors:
D. L. McDanels; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
 | The only results of the elctrical properties of fiber-reinforced composites noted in the literature for composites in which silver or copper matrices were reinforced with fibrous felts of tungsten. The results obtained indicated a linear increase in resistivity with fiber content to the maximum fiber content tested (40 volume %). However, it will be shown by the results of this NASA investigation that what appeared to be a linear relation ... |
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| Evaluation of One Type of Foldable Tube |
DEC 1965 |
24 pages |
| Authors:
Laurence W. Gertsma; James H. Dunn; Erwin E. Kempke Jr; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Stress-Intensity Factors for Three-Point Bend Specimens by Boundary Collocation |
DEC 1965 |
15 pages |
| Authors:
Bernard Gross; John E. Srawley; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| A boundary value collocation procedure was applied to the Williams stress function to determine values of the stress intensity factor K for single edge in rectangular section specimens subjected to three point bending. The results are presented in terms of the dimensionless quantity Y2 = K2B2W3/M2 where B and W are the specimen thickness and depth and M is the bending moment at midspan. The values of Y2 as a ... |
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| Dependence of Adsorption Properties on Surface Structure for Body-Centered-Cubic Substrates |
DEC 1965 |
24 pages |
| Authors:
Robert J. Bacigalupi; Harold E. Neustadter; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The Lennard-Jones 6-12 atom interaction potential is applied to the calculation of adsorption energy of an atom onto as many as 132 sites on a unit cell area of each of the eight highest surface density planes of a body-centered-cubic substrate. From the calculations, topographical maps of adsorption energy on a unit cell area of each plane for various adsorbate-adsorbent combinations are plotted. Normalized values of maximum adsorption energies and ... |
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| Two-Dimensional Heat Transfer in Radiating Stainless-Steel-Clad Copper Fins |
DEC 1965 |
26 pages |
| Authors:
Norbert O. Stockman; Edward C. Bittner; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| An analysis of the two-dimensional heat transfer in a radiating composite fin is presented together with details of the numerical method of solution. Several stainless-steel-clad copper fins typical of finned-tube space radiators are analyzed over a range (0 to 1) of stainless-steel to copper thickness ratio. Items discussed are temperature profiles along the fin length, temperature drop across fin thickness, effective conductivity, fin efficiency, heat rejection rate per unit weight, ... |
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| Analysis of Shear Bond Strength of Plasma-Sprayed Alumina Coatings on Stainless Steel |
NOV 1965 |
19 pages |
| Authors:
Salvatore J. Grisaffe; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The effects of various surface roughness conditions and spray powders on the shear bond strength of plasma-sprayed alumina coatings on AISI 304 stainless steel were investigated. Substrate root-mean-square surface roughness values examined ranged from near 0 to 280 microinches with intermediate values at 115 and 225 microinches. Spray powders varied in particle size range, size distribution, median particle size, and purity. Coatings on polished surfaces showed zero bond strength, which ... |
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| Analysis of Low-Temperature Direct-Condensing Vapor-Chamber Fin and Conducting Fin Radiators |
NOV 1965 |
60 pages |
| Authors:
Henry C. Haller; Bruce G. Lindow; Bruce M. Auer; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| An analytical comparison of flat, direct-condensing finned-tube space radiators employing vapor- chamber, double, and central fin-tube geometries was made for a low power output, low-temperature Rankine space power system. The descriptive equations for the radiator investigation included in addition to the heat-transfer analysis, consideration of vapor and liquid headers, pressure drop in the headers and radiator tubes, meteoroid protection for the tubes, headers, and vapor-chamber fins, and temperature drop in ... |
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| Bearing Life and Failure Distribution as Affected by Actual Component Differential Hardness |
NOV 1965 |
22 pages |
| Authors:
Erwin V. Zaretsky; Richard J. Parker; William J. Anderson; David W. Reichard; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Rolling-contact fatigue tests were performed on SAE 52100 207-size deep-groove ball bearing determine the relation between bearing fatigue life and actual bearing component hardness differences and the effect of actual component hardness differences on bearing fatigue life scatter. The 207-size bearings with inner and outer races from the same heat of SAE 52100 material and with nominal Rockwell C hardnesses of 63 were assembled with SAE 52100 balls from the ... |
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| Vapor-Deposited Thin Gold Films as Lubricants in Vacuum (10-11 mm Hg) |
OCT 1965 |
15 pages |
| Authors:
Talivaldis Spalvins; Donald H. Buckley; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| Thin gold films were vapor deposited on nickel, nickel-chromium, and nickel rhenium surfaces to be used for lubrication purposes. The durability of the film was determined by friction characteristics. Durability and strong bonding (adhesion) between the film and the substrate are essential when thin films are used as lubricants. Two methods of substrate preparation for vapor deposition were investigated: (1) mechanical polishing and (2) electron bombardment. Friction experiments were conducted ... |
|
| Thrust Coefficients of Low-Thrust Nozzles |
OCT 1965 |
30 pages |
| Authors:
Ernie W. Spisz; Paul F. Brinich; John R. Jack; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The performance losses associated with small nozzles operating at low propellant flow rates were investigated experimentally with a resistance-heated hydrogen thrustor. Data were obtained for seven different nozzles covering the range of nozzle area ratio from 25 to 150, hydrogen propellant flow rates of 0. 5x10 to the -4, 1.0x10 to the -4, and 2.5x10 to the -4 pound per second, and propellant temperatures from 530 to 4000 R. The ... |
|
| Strength Comparison of Flawed Single-Layer and Multilayer AISI 301 Stainless Steel Pressure Vessels at Cryogenic Temperatures |
OCT 1965 |
24 pages |
| Authors:
William S. Pierce; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| An experimental investigation was conducted to determine the strengths of single-layer and multilayer scale model tanks of AISI 301 stainless steel containing sharp notches and having the same total wall thickness. Material was used for both the single- layer and multilayer tanks having 60- and 70-percent cold reduction. The tanks were pressurized to burst at -320 and 423 F. Smooth, sharp-edge-notch, and sharp- center-notch tensile specimens were tested to provide ... |
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| Elevated-Temperature Tensile Properties of Alloyed Tungsten Fiber Composites |
OCT 1965 |
32 pages |
| Authors:
Donald W. Petrasek; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The effects of selected alloying elements on the elevated temperature tensile properties of tungsten fiber reinforced composites were studied. Composites were made of copper, copper- 2 percent chromium and copper- 10 percent nickel reinforced with various volume percents of uniaxially oriented tungsten fibers. The composites were tested in tension at temperatures up to 1800 degrees F. A comparison of the elevated-temperature tensile properties of tungsten fiber - copper alloy composites, ... |
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| Influence of Order-Disorder Transformation on Friction Characteristics of Copper-Gold Alloys in Vacuum |
SEP 1965 |
15 pages |
| Authors:
Donald H. Buckley; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| The influence of order and the order-disorder transformation for copper-gold alloys on friction was determined in vacuum. The copper-gold alloys contained 10, 25, or 50 atomic percent gold. The latter two alloys are the compounds Cu3Au and CuAu. Both Cu3Au and CuAu exhibit ordering, while the 10 atomic percent gold in copper does not. Friction experiments were conducted in vacuum (10 sub -10 mm Hg) with a hemispherical rider specimen ... |
|
| Effect of Variations in Silicon and Iron Content on Embrittlement of a Cobalt-Base Alloy (L-605) |
SEP 1965 |
26 pages |
| Authors:
Gary D. Sandrock; Richard L. Ashbrook; John C. Freche; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
|
| An investigation was conducted to study the effect of variations in silicon and iron content in L-605 (HS-25) on room-temperature ductility and other mechanical properties after aging at 1800 deg F for various times up to 1000 hours. The silicon content of the alloy was investigated over a range from 0.12 to 1.00 percent, and the content over a range from 0.16 to 3.24 percent. These ranges are generally within ... |
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| Extrusion at Temperatures Approaching 5000 degs F |
SEP 1965 |
24 pages |
| Authors:
Charles A. Gyorgak; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
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| Development of refractory metal alloys having high strength at temperatures in excess of 3000 degrees F requires methods of ingot breakdown or working at temperatures much higher than the use temperatures. Extrusion generally has been the most successful method. However, extrusion containers and other tooling melt in the temperature range 2400 degrees to 2600 degrees F and since maximum retention of billet temperature is desired, special handling methods are necessary. ... |
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