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266
May 30, 2011
05/11
by
Shirron, Peter; Canavan, Edgar; DiPirro, Michael; Jackson, Michael; King, Todd; Panek, John; Tuttle, Jame
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We present test results of the first adiabatic demagnetization refrigerator (ADR) that can produce continuous cooling at sub-kelvin temperatures. This system uses multiple stages that operate in sequence to cascade heat from a continuous stage up to a heat sink. Continuous operation aids the usual constraints of long hold times and short recycle times that lead to the generally large mass of single-shot ADRs, and allows us to achieve much higher cooling power per unit mass. Our design goal is...
Topics: THERMODYNAMICS, NANOTECHNOLOGY, MOLECULAR DYNAMICS, SURFACE LAYERS, GOLD, THERMAL EXPANSION, FAST...
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349
May 28, 2011
05/11
by
Samareh, Jamshid A
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This paper presents a novel parameterization approach for complex shapes suitable for a multidisciplinary design optimization application. The approach consists of two basic concepts: (1) parameterizing the shape perturbations rather than the geometry itself and (2) performing the shape deformation by means of the soft objects animation algorithms used in computer graphics. Because the formulation presented in this paper is independent of grid topology, we can treat computational fluid dynamics...
Topics: LITHIUM ALLOYS, MOTIVATION, PHASE TRANSFORMATIONS, WELDING, CRYOGENICS, FRACTURE STRENGTH,...
30
30
Jun 22, 2017
06/17
by
McFadden, G. B.; Eggleston, J. J.; Voorhees, P. W.
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Topics: Dendritic crystals -- Mathematical models, Crystal growth -- Mathematical models, Anisotropy, Phase...
Title from cover
Topics: REFRIGERANTS., OIL CONTAMINATION., PHASE TRANSFORMATIONS.
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68
Oct 5, 2015
10/15
by
Lloyd, John R.;Marto, P. J.
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Title from cover
Topic: REFRIGERANTS.,OIL CONTAMINATION.,PHASE TRANSFORMATIONS.
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382
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The contents include the following: The Journey Back;What GOES Around, Comes Around;Marbles for the Imagination;End-to-End Commitment;Fly Away; Going Up; Say What You Mean; ASK Talks with William Ready.
Topics: MICROGRAVITY, MELTING POINTS, INVISCID FLOW, LIQUID PHASES, ALUMINUM OXIDES, YTTRIUM OXIDES,...
169
169
Jul 11, 2010
07/10
by
Zebus, P. P
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An adjustable securing base had a surface radius of curvature which was adjusted to support an adjacent part on the base surface. The securing base comprised of a flexible thin plate with an adjustment mechanism connected on opposite edges of the base for adjusting the plate curvature. An opening in the plate was coupled to a vacuum device for securing the part adjacent to the plate surface.
Topics: APOLLO SOYUZ TEST PROJECT, SOLIDIFICATION, SPACE COMMERCIALIZATION, TEMPERATURE CONTROL,...
955
955
Jun 27, 2010
06/10
by
Smith, R. C
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eye 955
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No Abstract Available
Topics: MANY BODY PROBLEM, PHASE TRANSFORMATIONS, THERMODYNAMIC PROPERTIES, HIGH TEMPERATURE RESEARCH,...
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409
Jul 11, 2010
07/10
by
NON
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No Abstract Available
Topics: CENTRIFUGING, HEAT TRANSFER, SURFACE COOLING, TURBINE BLADES, ETHYL ALCOHOL, PHASE TRANSFORMATIONS,...
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296
Jul 26, 2010
07/10
by
Phillips, William H
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No Abstract Available
Topics: HIGH PRESSURE, SODIUM, PHASE TRANSFORMATIONS, PRESSURE MEASUREMENT, TRANSITION PRESSURE,...
590
590
Jul 11, 2010
07/10
by
NON
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A binary coded input signal is converted to a binary coded decimal signal having N decades by employing N four bit shift registers. The bits of the input signal are sequentially supplied, in order, to the least significant position of the register for the units decade, with the most significant bit of the input signal being applied to the units register first. Each of the registers includes a right shift-parallel load mode control input terminal. In response to the sum of the values stored in...
Topics: APOLLO SOYUZ TEST PROJECT, PHASE TRANSFORMATIONS, SOLIDIFICATION, SPACE COMMERCIALIZATION,...
157
157
Jul 21, 2010
07/10
by
Stencel, R. E
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A multistep scenario which describes a plausible mass loss mechanism associated with red giant and related stars is outlined. The process involves triggering a condensation instability in an extended chromosphere, leading to the formation of cool, dense clouds which are conducive to the formation of molecules and dust grains. Once formed, the dust can be driven away from the star by radiation pressure. Consistency with various observed phenomena is discussed.
Topics: CARBON, POLYMERIZATION, TRANSMISSION ELECTRON MICROSCOPY, CRYSTALLIZATION, GRAIN SIZE,...
233
233
Jul 26, 2010
07/10
by
Sjogren, Jon A
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Markov and semi-Markov processes are increasingly being used in the modeling of complex reconfigurable systems (fault tolerant computers). The estimation of the reliability (or some measure of performance) of the system reduces to solving the process for its state probabilities. Such a model may exhibit numerous states and complicated transition distributions, contributing to an expensive and numerically delicate solution procedure. Thus, when a system exhibits a decomposition property, either...
Topics: AEROSPACE SYSTEMS, GENERAL OVERVIEWS, INTERFACIAL TENSION, LIFE SUPPORT SYSTEMS, RESEARCH...
13
13
Jun 28, 2019
06/19
by
March, Norman H. (Norman Henry), 1927-
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xi, 274 p. : 24 cm. --
Topic: Phase transformations (Statistical physics)
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236
Jun 21, 2010
06/10
by
Miller, C. G.; Truscello, V. C
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Compatibility and shielding analysis of science instruments in spacecraft containing radioisotope thermoelectric generator
Topics: BINARY SYSTEMS (MATERIALS), COBALT, DUCTILITY, MARTENSITIC STAINLESS STEELS, MOLYBDENUM, NIOBIUM...
347
347
May 6, 2010
05/10
by
Kounaves, S. P.; McElhoney, K.; Shusterman, J; Hecht, M. H.; Kapit, J.; Quinn, R. C.; Catling, D. C.; Clark, B. C.; Ming, D. W.; Gospodinova, K.; Hredzak, P.
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Over the past several decades, elemental sulfur in martian soils and rocks has been detected by a number of missions using X-ray spectroscopy [1-3]. Optical spectroscopy has also provided evidence for widespread sulfates on Mars [4,5]. The ubiquitous presence of sulfur in soils has been interpreted as a widely distributed sulfate mineralogy [6]. However, direct confirmation as to the identity and solubility of the sulfur species in martian soil has never been obtained. One goal of the Wet...
Topics: ATMOSPHERIC GENERAL CIRCULATION MODELS, STRATIFICATION, STOCHASTIC PROCESSES, CLIMATE MODELS,...
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150
May 22, 2011
05/11
by
Cruz, Christopher I.; Ware, George M
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Wind tunnel tests were made with a scale model of the HL-20 in the Langley Unitary Plan Wind Tunnel. Pitch control was investigated by deflecting the elevon surfaces on the outboard fins and body flaps on the fuselage. Yaw control tests were made with the all movable center fin deflected 5 deg. Almost full negative body flap deflection (-30 deg) was required to trim the HL-20 (moment reference center at 0.54-percent body length from nose) to positive values of life in the Mach number range from...
Topics: ALLOYS, PHASE TRANSFORMATIONS, SURFACE PROPERTIES, TRANSPORT PROPERTIES, COMPUTERIZED SIMULATION,...
447
447
May 31, 2011
05/11
by
Chandrasekhara, M. S.; Wilder, M. C.; Carr, L. W
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A novel way of controlling flow separation is reported. The approach involves using an adaptive airfoil geometry that changes its leading edge shape to adjust to the instantaneous flow at high angles of attack such that the flow over it remains attached. In particular, a baseline NACA 0012 airfoil, whose leading edge curvature could be changed dynamically by 400% was tested under quasi-steady compressible flow conditions. A mechanical drive system was used to produce a rounded leading edge to...
Topics: COLLOIDS, PHASE TRANSFORMATIONS, KINETICS, MORPHOLOGY, CRYSTALS, GELS, MICROGRAVITY
Paftial phase diagrams are presented for the systems titanium-aluminum, titanium-chromium, titanium-iron, titanium-chromium-iron, and titanium-oxygen. All studies are completed except for the titanium-chromium-iron system, which requires further confirmatory work in certain areas.
Topics: DTIC Archive, Van Thyne, R. J., Bumps, E. S., Kessler, H. D., Hansen, M., ARMOUR RESEARCH...
Magnetite was shown to transform from the cubic to the orthorhombic system at temperatures below 119 deg K. The thermal expansion coefficient of the c axis became negative below 119 deg K, and at about 95 deg K there was no appreciable difference in the spacing of (440) and (008). The dimensions of the magnetite unit cell were measured at 295 deg, 128 deg, and 78 deg K and the resulting volumes were 591.4, 589.1, and 589.6 A to the power of 3, respectively. From these data and the c-axis length...
Topics: DTIC Archive, Abrahams, S. C., Calhoun, B. A., MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR...
Topics: DTIC Archive, Shirane, GenN, Pepinsky, Ray, PENNSYLVANIA STATE UNIV UNIVERSITY PARK X-RAY AND...
Topics: DTIC Archive, Bickford, Jr, L. R., NEW YORK STATE COLL OF CERAMICS ALFRED, *PHASE TRANSFORMATIONS,...
Results on the transformation of austenite to upper bainite in AISI 1085 and 4340 steels are presented as well as preliminary data on the mechanical properties of lower bainite resulting from stress application during isothermal transformation. Experiments on AISI 1085 indicated that an applied stress exceeding the yield stress of the austenite increased the amount of transformation. The increment in transformation was related in the same manner to a critical true strain and deformation energy...
Topics: DTIC Archive, Kehl, George L., Bhattacharyya, Subrata, HENRY KRUMB SCHOOL OF MINES NEW YORK, *PHASE...
Studies were made of the oxidation resistance of certain Mo alloys and of metallic-coated Mo. Data giving a comparison of the oxidation characteristics of high purity Mo with those of Mo-Co, Mo-Ni, and Mo-Cd alloys are included as well as results on Mo coated with Mg, Pb, and Ba. Nickel molybdate at high temperatures formed a highly protective coating on Mo which was broken by spalling on cooling. Tests made by quenching nickel molybdate into ice water indicated that spalling is probably not...
Topics: DTIC Archive, Spretnak, J. W., Speiser, Rudolph, OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS,...
Silver is a beta former when alloyed in small amounts with titanium. There is a large range of solubility of silver in alpha titanium and it reaches a maximum of 9 + 1 wt.% silver at 1560 +/- 7 F, at which temperature an eutectoid reaction, beta+ TiAg, occurs at 17 + 0.5 wt.% silver. The beta solid solubility increases to 30.5 +/- 1 wt.% silver at 1903 +/- 5 F. Contrary to general opinion, the existence of the compound TiAg (69.25 wt.% Ag) has been established. It is formed at 1903 +/- 5 F by...
Topics: DTIC Archive, Adenstedt, Henry K., Freeman Jr, William R., WRIGHT AIR DEVELOPMENT CENTER...
Topics: DTIC Archive, Kehl, George L., Bhattacharyya, Subrata, HENRY KRUMB SCHOOL OF MINES NEW YORK,...
A Pound-Knight-Watkins type of RF spectrometer (Rev. Sci. Instr. 21:219, 1950) was used in measuring the shift of nuclear resonance and the line width in alpha- and beta-Sn, Th, Pb, and several alloys. A permanent magnet with a field of about 6000 gauss in a 1.25-in. gap and with 4-in.-diam pole faces was also used. A few measurements were made with an electromagnet at fields between 2000 and 5500 gauss. The samples were made from powdered metals suspended in mineral oil. Gray Sn showed no...
Topics: DTIC Archive, Bloembergen, N., Rowland, T. J., HARVARD UNIV CAMBRIDGE MA CRUFT LAB, *METALS,...
A preliminary dielectric study of KNbO3 single crystals, prepared without flux, showed a sharp peak in the dielectric constant at -50 C on cooling and -35 C on heating, indicating the existence of a phase transition at this point. Further study was carried out on the dielectric, structural, and thermal properties of this lowest phase. KNbO3 single crystals were prepared as described by E. A. Wood (Acta Cryst. 4:353, 1951), using KCO3 as a flux and cooling down from 1000 C. Dielectric tests were...
Topics: DTIC Archive, Shirane, G., Dannes, H., Pavlovic, A., Pepinsky, R., PENNSYLVANIA STATE UNIV...
A method is presented of calculating the equilibrium phase boundary which requires only an equation of state for mixtures and the set of constants for each of the pure components. The binary system of n-heptane and nitrogen is investigated. The results which are graphed for 298.13 deg, 373.13 deg, 448.13 deg, and 498.13 deg K appeared to be in agreement with the experimental results of Palmer, Hirschfelder, and Boyd. (NRL, CM-702) but not with those of Boomer, Johnson, and Piercy (Can. J....
Topics: DTIC Archive, Galloway, George, Town, Duplaise, WISCONSIN UNIV-MADISON THEORETICAL CHEMISTRY INST,...
Topics: DTIC Archive, Rhines, F. N., Bond, W. E., Rummwl, R. A., CARNEGIE INST OF TECH PITTSBURGH PA METALS...
Conclusions pertaining to phase transformations in the uranium-oxygen system, based on the kinetic investigations of the reduction and oxidation processes of uranium oxides supplemented by an X-ray diffraction study of the products obtained are presented.
Topics: DTIC Archive, Strekalovskiy, V N, FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH, *URANIUM...
The nucleation rate of the alpha (gray) to beta (white) tin transformation was measured as a function of temperature and alpha tin particle ize by an x-ray diffraction technique. The power specimens of alpha tin were essentially monodisperse and the small dimension of the particles of these specimens was varied from 13 to 75 microns. The fraction isothermall tran formed as a function of time was determined continually from integrate intensity measurements of the 220 x-ra reflection of alpha...
Topics: DTIC Archive, DURDALLER, C G, METAL HYDRIDES INC BEVERLY MA, *PHASE TRANSFORMATIONS, *NUCLEATION,...
The goal of the present program is to measure some of the material properties under shock conditions in simple rocks and minerals. The pressure region of interest is the region in which the material strength of the rock affects the shock wave. The property that is measured is the Hugoniot equation of state. From measurements of this function, information is obtained about such aspects as phase transitions, elastic wave amplitudes and velocities, and pressure volume relations above the elastic...
Topics: DTIC Archive, Gregson, V G, STANFORD RESEARCH INST MENLO PARK CA POULTER LABS, *ROCK, *SEISMIC...
The investigation was directed toward two main objectives: (1) to develop Time-Temperature Transformation (TTT) diagrams for several uranium base alloys, and (2) to develop metallographic techniques suitable for the identification of phases, intermetallic compounds and nonmetallic constituents in these and several other alloys. Accordingly, the report is presented in two parts dealing separately with each of these topics. TTT diagrams are presented and transformation kinetics are described for...
Topics: DTIC Archive, Repas, P E, CASE INST OF TECH CLEVELAND OH, *PHASE TRANSFORMATIONS, *URANIUM ALLOYS,...
The velocity of the interface between liquid and vapor phases when a slightly superheated liquid changes to vapor is found. The temperature distribution in the liquid ahead of the evaporation front can then be determined by a numerical integration.
Topics: DTIC Archive, Brand, R S, CONNECTICUT UNIV STORRS, *LIQUIDS, *PHASE TRANSFORMATIONS, *EVAPORATION,...
An analytical and experimental study was conducted to investigate the principal mechanisms of water and carbon dioxide freeze-out and to develop a method for predicting the effects of contaminant freeze-out on heat exchanger performance. This program has included an analytical study of the various mechanisms by which contaminant freeze-out may occur. A test facility was constructed having the capability of simulating a wide range of air stream pressures, temperatures, mass flow, and...
Topics: DTIC Archive, Burke, J C, LITTLE (ARTHUR D) INC CAMBRIDGE MA, *PHASE TRANSFORMATIONS, *HEAT...
The migration of slab, cylindrical and spherical zones through a block of solid under the influence of a temperature gradient has been analyzed theoretically. The migration rate is found to be directly proportional to the temperature gradient in the system and to depend upon orientation dependent atomic kinetics of the melting freezing processes. The magnitude of the atomic kinetic effect depends upon the size of the molten zone. Stable zone migration occurs only in certain crystallographic...
Topics: DTIC Archive, Tiller, W A, WESTINGHOUSE ELECTRIC CORP PITTSBURGH PA, *ZONE MELTING, PHASE...
The migration of slab, cylindrical and spherical zones through a block of solid under the influence of an electric field gradient has been analyzed theoretically. It was determined that the zone could migrate either up or down the field gradient, E*, depending upon the magnitude and sign of (i) the effective ionic mobility of the solvent atoms, U, (ii) the Peltier coefficient at the solid-melt interface, and (iii) the imposed temperature gradient, G*.
Topics: DTIC Archive, Tiller, W A, WESTINGHOUSE ELECTRIC CORP PITTSBURGH PA, *PELTIER EFFECT, *ZONE...
This report deals with accurate determinations of basic properties of phases in systems of transition metals and non-metals. These studies are mainly confined to the borides, silicides and phosphides of transition metals from Groups VI, VII and VIII. Comprehensive and detailed reviews of the binary transition metal borides, silicides and phosphides have been given in Technical Notes No. 13 and 34. The present report is therefore confined to general aspects only, which are presented in two main...
Topics: DTIC Archive, Hagg, Gunnar, UPPSALA UNIV (SWEDEN), *PHASE TRANSFORMATIONS, *PHOSPHIDES, *BORIDES,...
Experiments on the initiation of detonation in cast and pressed explosives, subjected to plane shocks introduced at a plane surface, are discussed. Shock amplitudes ranging from 28 to 140 kilobars in the explosive were generated by using plane wave lenses with various combinations of donor explosive and barrier composition and geometry. The shock velocity was obtained in each sample as a function of distance of travel into the wedge-shaped specimen from distance time records obtained with a...
Topics: DTIC Archive, Jacobs, S J, NAVAL ORDNANCE LAB WHITE OAK MD, *SHOCK WAVES, *DETONATIONS, VELOCITY,...
This report describes the density measurements as a function of temperature and pressure (PVT relations) made on solid He4. The isothermal compressibility and the volume changes at the phase transitions have been accurately measured in the region of the body-centered-cubic solid phan estimate is made of the isobaric thermal expansion coefficient. The data suggest that thermodynamic relations predicting a negative thermal expansion coefficient in the solid might be altered by the fact that the...
Topics: DTIC Archive, Kidder, J N, YALE UNIV NEW HAVEN CT, *ISOTOPE EFFECT, *LIQUID HELIUM, *SUPERFLUIDITY,...
It is suggested that the inner core of the earth may be a new high pressure phase of iron. The observed density is in accord with a phase transition presumed to be associated with the transfer of two of the '3p' electrons of the 'argon core' of atomic iron to the '3d-4s' band. The high pressure phase would be ferromagnetic and have an estimated Curie temperature of about 5500 K. The earth's magnetic field would arise from the residual magnetization of the unmagnitized ferromagnetic core....
Topics: DTIC Archive, Weiss, R J, ARMY MATERIALS RESEARCH AGENCY WATERTOWN MA, *GEOMAGNETISM, PHASE...
A method for testing the behavior of thin tungsten wires at bending deformation is described. All tungsten wires show, within a narrow temperature range, the transition from brittle to ductile behavior. For wires with a fiber texture this transition temperature T sub e is below zero C; for recrystallized wires, at 150-400C. Long-crystalline wires have a lower T sub e than the short- crystalline ones. The position T sub e is determined by the form of the fracture (transcrystalline resp....
Topics: DTIC Archive, REDSTONE SCIENTIFIC INFORMATION CENTER REDSTONE ARSENAL AL, *PHASE TRANSFORMATIONS,...
Hugoniot curves for Plexiglas and polystyrene were established experimentally using optical and polarization techniques. Both Hugoniots show evidence of a phase transition, although the polystyrene transition is more clearly defined than that of Plexiglas. Separate polarization studies support the existence of both transitions. At the transitions, it is noted that the rarefaction velocity becomes equal to the shock velocity. The nature of the transitions is presently unknown.
Topics: DTIC Archive, ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD, *STYRENE PLASTICS, *HUGONIOT...
The kinetics of free radical polymerization were treated theoretically under the assumption that the reaction temperature increases at constant rate (T = const). From The Arrhenius relationships for the kinetic rate constants, approximate corresponding functions of time were derived, which transformed the kinetic equations accordingly. A differential equation describing the sum of the concentrations of all free radicals appearing in such a system was solved by approximation, and from the...
Topics: DTIC Archive, AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH, *POLYMERIZATION, *FREE RADICALS,...
PHAS20 performs simultaneous multiple regression of a mathematical model for the functional relations among thermodynamic quantities to experimental data for a group of chemically related species. The thermodynamic quantities included are heat capacity, entropy, enthalpy, free energy, equilibrium constant, electrochemical potential, and relative heat content. PHAS20 will fit the model to 70 sets of data containing a total of 1200 observations on 20 species. The program is divided into 4 major...
Topics: DTIC Archive, Haas, Jr, John L, GEOLOGICAL SURVEY RESTON VA, *COMPUTER PROGRAMS, *THERMOCHEMISTRY,...
A practical camouflage system whose colors and color patterns can be continuously, controllably and reversibly varied on command would be of great tactical importance to mobile army units. In the study described a number of possible approaches were researched, an extensive literature search was carried out, and some laboratory investigations performed. From considerations of each of these approaches, the state-of-the-art in materials technology, and of the requirements of the program, a liquid...
Topics: DTIC Archive, Gilligan, J E, IIT RESEARCH INST CHICAGO IL, *CAMOUFLAGE, *LIQUID CRYSTALS, *COLORS,...
The reversion stress of NiTi is characterized under several unique thermomechanical situations. The effect of partial reversion of initial strain on the reversion stress is studied. The final stress is apparently not dependent on whether the initial strain is lost by stress-free reversion or stress-reversion. The effect of developed stress on the temperature range for the reversion transformation to austenite is also studied. A model for the mechanism of constant-stress reversion is proposed.
Topics: DTIC Archive, Such, Carliss R, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *NICKEL ALLOYS, *STRESSES,...
A tutorial discussion of the response of materials to laser radiation is presented, with emphasis on simple, intutive models. Topics discussed include optical reflectivity of metals at IR wavelengths laser-induced heat flow in materials, the effects of melting and vaporization, the impulse generated in materials by pulsed radiation, and the influence of the absorption of laser radiation in the blowoff region in front of the irradiated material.
Topics: DTIC Archive, Schriempf, J T, NAVAL RESEARCH LAB WASHINGTON DC, *LASER BEAMS, METALS, PHASE...
Nb-Co-Al and Nb-Fe-Al base alloys have been studied to determine the effects of composition both elemental and constituent (i.e., intermetallic alloy compounds used to make alloys) on the oxides formed during 1200C oxidation in air. Alloys were formed by both pressing and sintering of intermetallic compounds and elemental powders and by arc melting alloy buttons from intermetallic compounds and elements in powder form. Oxidation kinetics have been measured, and the oxides formed have been...
Topics: DTIC Archive, Svedberg, Robert C, WESTINGHOUSE ASTRONUCLEAR LAB PITTSBURGH PA, *NIOBIUM ALLOYS,...
