Showing papers on "Texture (crystalline) published in 1975"
TL;DR: In this paper, the dynamic elastic moduli of Zircaloy-2, Zr-1.15 wt% Ci-0.1 wt % Fe and Zr 2.5wt% Nb have been determined over the temperature range 293-773 K.
101 citations
TL;DR: The unit cell of poly(tetramethylene terephthalate) is triclinic with parameters a = 5.96 A, b = 4.83 A, c (fiber axis) = 11.3°; space group P1, calculated crystalline density 1.41 g/cc as mentioned in this paper.
Abstract: The unit cell of poly(tetramethylene terephthalate) is triclinic with parameters a = 5.96 A, b = 4.83 A, c (fiber axis) = 11.62 A, α = 115.2. β = 99.9, and γ = 111.3°; space group P1, calculated crystalline density 1.41 g/cc. The plane of the benzene ring is found to be inclined by about 15° from the fiber axis, contributing to a shortening of the fiber period as compared to the period expected on the basis of analogy with other members of the terephthalate ester series. The remaining shortening of the fiber period occurs in the O°CH2°CH2segment of the chain. No abnormally short distances among neighboring chain atoms were observed. A typical texture pattern was found in specimens of this polymer that were cold rolled and subsequently annealed. In this texture the c axis of the unit cell is highly oriented in the rolling direction; the a and b axes of the unit cell are oriented preferentially so that the terephthalate residue lies as close as possible to the plane of rolling.
99 citations
TL;DR: In this article, the method of reactive co-sputtering was used to determine the optimum dopant concentration for low resistivity In 2 O 3 /SnO 2 and SnO 2 /Sb 2 O 5 films.
90 citations
TL;DR: In this paper, a series of NiO samples has been prepared from Ni(OH)2, at low temperature, in air flow, and the starting hydroxide is obtained from a Turstratic Hydroxide in the form of thin platelets suitable for electron microscopy and selected area diffraction studies.
61 citations
TL;DR: In this paper, a characteristic structural organization consisting of poorly organized spherulites with an open fibrous texture in which the strands appear to be built up from microfibils was revealed.
Abstract: Electron microscopy reveals a characteristic structural organization consisting of poorly organized spherulites with an open fibrous texture in which the strands appear to be built up from microfibils. X-ray and birefringence results are also discussed.
59 citations
TL;DR: The cylindrical texture camera described in this paper employs a fiat specimen inclined to the incident X-ray beam, which, as in the above cases, is along the cylinder axis, and is capable of detecting and identifying very thin deposits and of characterizing the type of preferred orientation that may have occurred.
Abstract: X-ray diffraction cameras in which the diffraction pattern is recorded on a cylindrical photographic film coaxial with the incident beam have previously been used to make measurements of preferred orientations in polycrystalline materials by Kratky (1930), Wooster (1948), Mackay (1953) and Richards (1964). The diffraction cones of constant 20 intersect the recording film in straight lines. These may then be scanned with a linear densitometer to yield intensity distributions characteristic of the preferred orientation, allowing for the effects of X-ray absorption in the specimen. The uniaxial textures of continuously rotated drawn wires and graphite specimens, mounted normal to the camera axis, have been studied by Mackay (1953) and Richards (1964). The more complex moving-film method of Wooster (1948) has been used to plot the pole figures of rolled sheets. The cylindrical texture camera described here employs a fiat specimen inclined to the incident X-ray beam, which, as in the above cases, is along the cylinder axis. The camera is particularly applicable to the crystallographic examination of thin crystalline films deposited on flat substrates. It is capable of detecting and identifying very thin deposits and of characterizing the type of preferred orientation that may have occurred. For cases where orientation effects are not pronounced, consideration of the specimen absorption factors provides information about layer thickness and order of deposition when more than one layer is present.
54 citations
TL;DR: In this article, a procedure for the prediction of the texture of the product of a known crystallographic transformation from a known parent texture was described, and the predicted transformation texture is in good agreement with experimentally determined α-phase textures obtained both by air cooling and furnace cooling the same starting material through the α − β phase transformation.
46 citations
TL;DR: In this paper, the nucleation and growth of gold films evaporated onto graphite were studied by examining the film intact with the substrate using transmission electron microscopy and diffraction.
45 citations
TL;DR: In this paper, the effect of crystallographic texture on the anisotropies of strength and toughness of high tensile steels was quantitatively investigated, and it was found that among the main components of the textures of tlzese steels, {3 1J }<01J> orientations not only enhanced the difference in stmlgth between L (OO) and C(900) directions, but also reduced the toughness at 45° direction.
Abstract: The effect of crystallographic texture on the anisotropies of strength and toughness of the controlrolled high tensile steels was quantitatively investigated . The effect of the textures on the anisotro.bies of yield and tensile strees could be accurately evaluated with Hosford and B ackofen's method, if fine de tails of textures were properly taken in to account. The anisotropies of toughness were found to be qualitatively related with the dis tribution of { 100} cleavage plane. 1 t was f urther found that among the main components of the textures of tlzese steels, {3 1J }<01J> orientations not only enhanced the difference in stmlgth between L (OO) and C(900) directions, but also reduced the toughness at 45° direction, whereas {332}< 113> orientations gave rise to a weak anisotropy and better average strength and toughness . T hus, f urther im/Jrovemen t in strength and toughness might be eX/Jected,ij /Jreferential development of {332}< 113> orientations was to be achieved .
42 citations
TL;DR: In this paper, the effect of substrate temperature on the nucleation and growth of gold films vaporized on a single crystal graphite was studied using transmission electron microscopy and diffraction, and it was shown that the morphology of the gold particles changes with substrate temperature.
41 citations
TL;DR: In this article, a mechanism involving epitaxial deposition of chain segments onto growing lamellae is concluded to be responsible for formation of the bimodal crystal texture in flow-crystallized material.
Abstract: Electron microscopy, selected area electron diffraction, X-ray diffraction, and dynamic-mechanical testing have been used to study flow-crystallized and hot drawn isotactic polypropylene. As a result of these investigations, it was found that bimodal crystal textures can apparently be formed by at least two different treatments, but the corresponding morphologies are completely different. Flow-induced crystallization was observed to result in a microstructure of lamellae oriented perpendicular to the flow direction, while hot drawing of polypropylene films above a critical temperature produced a morphology of microfibrils lying parallel to the draw direction. Below this critical temperature, drawing produced a fibrillar morphology having only a typical unimodal fibre texture. As a result of information obtained here, a mechanism involving epitaxial deposition of chain segments onto growing lamellae is concluded to be responsible for formation of the bimodal crystal texture in flow-crystallized material.
Patent•
07 May 1975
TL;DR: In this article, a boat-shaped sanitary device is constructed from a hydrophilic, highly absorbent, polymeric foam material which has been rendered fluid-impervious on one side thereof by a coating of an organic polymeric latex material.
Abstract: A monolithic sanitary device comprising a generally arcuate, boat-shaped structure prepared from a hydrophilic, highly absorbent, polymeric foam material which has been rendered fluid-impervious on one side thereof by a coating of an organic polymeric latex material. The device dispenses with the need of elaborate barrier layers, the various facing and backing sheets, as the foam material possess a texture which is acceptable to living tissue and the fluid-impervious latex coating prevents undesirable strike-through and assists in maintaining the structural integrity of the device.
TL;DR: In this article, a microstructural study of an explosion shock-quench synthetic diamond has revealed that a large proportion of the crystallites in the polycrystalline particles were strongly oriented.
TL;DR: In this article, a model of the structure of a MoS 2 boundary film is proposed; its composition is explained on the basis of the anisotropy of the mechanical and physical properties of MoS2 crystals and the bonds between them.
Abstract: The effect of the substrate temperatures in a wide range between −150 and 270 °C on the grain size, crystal orientation, Hall mobility, and the carrier concentration of evaporated Te films has been investigated. The grain size and the corresponding Hall mobility were observed to increase remarkably with increasing substrate temperature above 50 °C and with decreasing temperature below 50 °C, contrary to the expectation. The carrier concentration decreased with increasing substrate temperature. The influence of Au nucleation centers on the crystallinity and electronic properties were also investigated. An x−ray diffractometer study indicated c−axis texture to occur with improving grain growth.
TL;DR: In this paper, the authors attempted to rationalize magnetic torque data by employing the crystal orientation distribution function and the formula for the anisotropy of energy for a single crystal of cubic symmetry.
Abstract: In this work we have attempted to rationalize magnetic torque data by employing the crystal orientation distribution function and the formula for the anisotropy of energy for a single crystal of cubic symmetry Three kinds of magnetic material of different texture were analyzed For each of these materials (110), (200) and (112) pole figures were measured by neutron diffraction and the orientation distribution functions were determined The series coefficients of the pole figure were used for the theoretical evaluation of the torque curve Torque curves measured with a magnetometer, were compared with the results from texture data Agreement is good both qualitatively and quantitatively for all specimens
TL;DR: In this article, the directionality of properties in α and α + β titanium alloys results primarily from the elastic and plastic anisotropy of the hexagonal lattice a-phase.
Abstract: Mechanical properties are influenced by direction of testing with respect to wrought microstructure. In aluminium alloys the properties most sensitive to direction are ductility, fracture toughness, and stress corrosion and this can be attributed to the well developed mechanical fibring that exists in these alloys. Crystallographic textures are developed, particularly in extrusions, and some useful enhancement of strength is achieved in the longitudinal direction. Nevertheless, from a general viewpoint mechanical fib ring produces the predominant effects. Directionality of properties in α and α + β titanium alloys results primarily from the elastic and plastic anisotropy of the hexagonal lattice a-phase. Directionality effects are discussed, including those exhibited by the fatigue, tensile, fracture toughness, creep, stress corrosion, and sustained load properties. The important benefit of plastic anisotropy in terms of texture strengthening is highlighted, and it is concluded that optimum proper...
Patent•
24 Jun 1975TL;DR: In this paper, the diffusivity of an impurity in a layer of polycrystalline silicon is controlled by forming the poly-stalline polysilicon on a thin nucleating layer.
Abstract: The diffusivity of an impurity in a layer of polycrystalline silicon is controlled by forming the polycrystalline silicon on a thin nucleating layer of polycrystalline silicon possessing a maximum {110} texture
TL;DR: In this paper, a continuous wire feed source of aluminium of 99.999% purity in conjunction with a composite ceramic boat has been used to deposit aluminium films of high purity in vacuum.
TL;DR: In this article, the morphology and orientation texture of nickel coatings obtained from a Watts electrolyte in the presence of iodine ions, butyne-2-diol 1,4, formalin and phthalic anhydride over a wide current density and temperature interval were investigated.
TL;DR: In this paper, a phenomenological model for determining the specific frictional energy needed to rotate a particle in the mixture is proposed. But the model is not suitable for orienting paramagnets, antiferromagnetic, ferri-and ferromagnets.
Patent•
15 Jan 1975
TL;DR: Expanded ready-eat cereal products of improved texture are produced by mixing with milled grain between 0.2 and 2% of finely divided, insoluble, inert, non-reactive material and processing the mixture through a high temperature and high pressure cooking extruder as discussed by the authors.
Abstract: Expanded ready to eat cereal products of improved texture are produced by mixing with milled grain between 0.2 and 2% of finely divided, insoluble, inert, non-reactive material and processing the mixture through a high temperature and high pressure cooking extruder. The inert materials are selected from the group consisting of titanium dioxide, calcium silicate, silicon dioxide, and aluminum oxide. The resulting products have a structure composed of cells which are substantially all of uniform small size and are of a tender friable texture.
TL;DR: In this paper, the influence of subgrain boundaries on the kinetics of high temperature creep is studied by comparing the creep properties of textured Fe-3 pct Si with the properties of randomly oriented polycrystalline samples of the same composition.
Abstract: The influence of subgrain boundaries on the kinetics of high temperature creep is studied by comparing the creep properties of textured Fe-3 pct Si with the properties of randomly oriented polycrystalline samples of the same composition. The steady state creep properties of the two materials are very nearly the same even though the randomly oriented polycrystalline samples exhibit subgrain formation while the textured samples do not. The transient creep properties of these materials are widely different indicating that the presence of subgrain structure can affect the transient creep behavior without affecting the steady state properties. We find that long creep delays produced by stress reductions during creep are associated with the presence of subgrain boundaries. The textured samples which have no subgrains do not show these transients. It is suggested that the creep transients for the randomly oriented polycrystalline samples are more sluggish than those for the textured samples because recovery involving subgrain boundary movement is slower than that for homogeneous dislocation rearrangement.
TL;DR: In this paper, surface texture formation is caused by an excess driving force which results in growth of grains with a low-surface-energy plane exposed at the substrate surface, since the surface energy of a crystallographic plane is a function of atmosphere and impurities adsorbed on the surface.
Abstract: Crystallographic texture formed at the surface during the sintering of 3 tape-cast Al2O3 substrates was studied as a function of sintering temperature and atmosphere The sintering atmosphere strongly influenced the surface texture formed A strong (001) basal-plane fiber texture normal to the plane of the substrate is produced when commercial green substrates are sintered in air at 1600° to 1700°C; sintering in vacuum (< 2 × 10-6 mm Hg) or dry H2 produces a weaker texture Grain growth is a necessary but insufficient condition for the formation of a strong surface texture It is proposed that surface texture formation is caused by an excess driving force which results in growth of grains with a low-surface-energy plane exposed at the substrate surface Since the surface energy of a crystallographic plane is a function of atmosphere and impurities adsorbed on the surface, both these factors should have a pronounced effect on surface texture formation, as observed in the present study
TL;DR: In this paper, the magnetic properties of Gd7Rh3 were measured by the Faraday technique between 100 and 800 K on samples of a weak, fibrous texture, which showed orientation-dependent antiferromagnetic ordering at 142 ± 1 K Above 470 K, normal Curie-Weiss behaviour was observed corresponding to the effective moment of tripositive gadolinium, with θp = 175 ± 7 K
Abstract: Measurements of the magnetic properties of Gd7Rh3 by the Faraday technique between 100 and 800 K on samples of a weak, fibrous texture showed orientation-dependent antiferromagnetic ordering at 142 ± 1 K Above 470 K, normal Curie-Weiss behaviour was observed corresponding to the effective moment of tripositive gadolinium, with θp = 175 ± 7 K
TL;DR: In this article, two methods are discussed which are capable of giving composition profiles in thick diffused films, and the results suggest that for those cases examined the diffusion-induced damage is comparable with that of highly deformed metals.
TL;DR: In this article, the texture correspondence between the preferred orientation axes of f.c.c and h.p.c was found upon investigation of the textures of two-phase electrolytic coatings consisting of cobalt and nickel-cobalt alloys.