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Showing 1 to 20 of 32 for “"NiAl"”.
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Reactive infiltration processing and compression creep of NiAl and NiAl composites
… infiltration processing of bulk and composite NiAl was investigated with powder and wire preforms of nickel. Inhomogeneous microstructures were often obtained with powder preforms because their high surface-to-volume ratio, low permeability, and irregular infiltration paths lead to simultaneous …
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Influence of High Temperature Creep upon the Structure of ß-NiAl and ß-NiAl(Fe) Single Crystals
… high temperature creep upon the structure of ß-NiAl and ß-NiAl(Fe) single crystals. A non-destructive procedure is established following the classic line of X-ray structure analysis, namely controlling the chemical composition with the electron probe microanalysis, determining the unit cell …
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Atomistic simulation of dislocation core structures in B2 NiAl
… core structures of the dislocations found in B2 NiAl. The core spreading of (100) dislocations in NiAl can occur along a variety of planes depending on dislocation slip plane and line orientation. Discrete lattice effects reduced the high strain levels from anisotropic elasticity solution at the …
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Interdiffusion Analysis For Nicocraly And Nial Vs. Various Superalloys
… NiCoCrAlY (beta + gamma) and single beta-phase NiAl with the selected alloys is measured. The diffusion couples were examined with an emphasis on the composition-dependence of Al interdiffusion. Microstructural analysis of the NiCoCrAlY vs. superalloys couples is performed to examine the …
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Microstructure and texture development during high-strain torsion of NiAl
In this study polycrystalline NiAl has been subjected to torsion deformation. Torsion has been used because of its characteristics. By this deformation mode high shear strains (gamma = 18 in this study) can be imposed on the sample. The deformation conditions are well-defined because of the local …
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Planar fault energies and dislocation core spreadings in B2 NiAl
The lack of ductility of the B2 NiAl alloy stands in the way of promising applications. In an effort to understand the dislocation behavior, computer simulation of the planar faults involved in the core spreadings of <100> and <111> dislocations was carried out. Seven γ-surfaces were computed for …
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Simulation of Bulk and Grain Boundary Diffusion in B2 NiAl
… atom interatomic potential developed to fit NiAl properties. Diffusion in the bulk occurs through a variety of cyclic mechanisms that accomplish the motion of the vacancy through nearest neighbor jumps restoring order to the alloy at the end of the cycle. The traditionally postulated six-jump …
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Computer simulation study of grain boundary structure in B2 NiAl
… of grain boundary structures in ordered NiAl was carried out. The considered boundaries were boundaries of low reciprocal coincident site density Σ. The structural unit model was used to obtain a general picture of the grain boundary features in NiAl. Relation between the grain boundary …
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Visualization and simulation of defect structures in the B2 phase of NiAl
… were applied to data from simulations of B2 NiAl to study extended dislocation cores and how these cores react to nearby point defects and applied stress. Such images may be viewed as a series of images forming an animation such that a simulated quantity, such as applied stress, is cast into …
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Untersuchung der Deposit-Substrat-Wechselwirkungen und des Oxidationsverhaltens von Nanopartikeln auf einem oxidischen Träger am Beispiel der Systeme Ni/Al 10 O 13/NiAl(110) und Ge/Al 10 O 13/NiAl(110)
… an den Modellkatalysatorsystemen Ni/Al10O13/NiAl(110) und Ge/Al10O13/NiAl(110) unter Verwendung von XPS und STM. Ersteres System weist stark ausgeprägte Deposit-Substrat Wechselwirkungen, und damit einhergehende, in unterschiedlichen Effekten begründete XP-Signalverschiebungen auf. Ab 375K …
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Defect Structures in Ordered Intermetallics; Grain Boundaries and Surfaces in FeAl, NiAl, CoAl and TiAl
… boundary structures in B2 aluminides, FeAl, NiAl and CoAl and <I>L</I>1₀ γ-TiAl were investigated using molecular statics and embedded atom potentials in order to explore general trends for a series of B2 compounds as well as TiAl. The potentials used correctly predict the proper mechanism of …
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Deformation mechanisms in B2 aluminides: shear faults and dislocation core structures in FeAl, NiAl, CoAl and FeNiAl
… with increasing ordering energy (FeAl, NiAl, CoAl). The simulation results in NiAl were compared with in-situ straining observations of dislocation motion. The dislocations simulated were of (100) and (111) types. The simulations results obtained indicate a strong influence of the planar …
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Alloying effects on high-temperature deformation behavior of nickel aluminide intermetallics
… for high temperature structural applications. NiAl is a desirable candidate based on its low density, high thermal conductivity, high melting temperature, and its proven oxidation resistance. Currently, limited ductility at lower temperatures and low creep resistance at high temperatures limit …
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Effects of Surface Oxidation on Vacancy Defects in Beta Nickel-Aluminum Alloys
… observations of the oxidation process in (beta)-NiAl alloys annealed under controlled conditions of temperature and oxygen partial pressure. Binary Ni-Al alloys, with nominally 47.5, 50.4 and 52.5 at .% Al, were examined. The Auger spectroscopy analysis showed that the predominant oxide formed on …
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Aufbau einer Molekularstrahlapparatur für oberflächenkinetische Untersuchungen
… und geordneten Al2O3-Film, präpariert auf einem NiAl(110)-Einkristall, deponierte Pd-Partikelarten zum Einsatz. Die Untersuchung der Wechselwirkung von Sauerstoff mit den Pd-Teilchen, also die Messung der Sauerstoffhaftkoeffizienten und -aufnahme des Probensystems im Temperaturbereich zwischen …
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Model studies on photocatalysis: laser induced CO desorption from platinum nanoparticles at an alumina support
… wurden durch oberflächliche Oxidierung eines NiAl(110) Kristalls präpariert. Durch Anregung mittels eines Nanosekundenlasers bei einer Wellenlänge lambda = 355 nm wurde versucht, eine laserinduzierte Desorption des auf den Pt Partikeln adsorbierten CO hervorzurufen. Der Einfluss der …
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The Onset and Blocking of Slip in Nickel Aluminide[001]
… slips and the general absence of dislocations in NiAl crystals. An intuitive explanation for the planar core of dislocations is also given.
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Computational modeling of indentation of materials
… numerical investigation of indentation on Cr(Mo)-NiAl eutectic alloy. More specifically, the depth dependent strain partitioning between the layers of NiAl layered structure was measured using X-Ray microdiffraction. Finite element simulations were conducted to evaluate thermal strains due to …
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Preparo e avaliação do hidróxido duplo lamelar de cálcio e alumínio na remoção de cobre(II), níquel(II), zinco(II) e cromo(VI) de solução aquosa
… na região do infravermelho dos HDLs de CuAl, NiAl e ZnAl obtidos no final do processo de remoção (pH 7,0), possibilitou verificar que os HDLs formados apresentam estruturas lamelares e contem como ânion interlamelar o íon carbonato (CO32-). A construção de curvas de precipitação para a remoção …
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Non-destructive Microstructural Evaluation Of Yttria Stabilized Zirconia, Nickel Aluminides And Thermal Barrier Coatings Using Electrochemical Impedance Spectroscopy
… for three different thickness and hot extruded NiAl alloy buttons which were subjected to isothermal oxidation with varying temperature and time. NiAl is as similar to the available commercial bondcoats used in TBCs. Then degradation monitoring with electrolyte penetration was carried out on …
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