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Showing papers on "Texture (crystalline) published in 1981"


Journal ArticleDOI
S. Vaidya1, A.K. Sinha1
TL;DR: In this article, the electromigration resistance of Al-0.5%Cu meander lines was found to increase with increasing grain size s and degree of {111} preferred orientation and with decreasing spread σ in the grain size distribution.

328 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical analysis of the deformation of foils in the biaxial bulge test was made and the relationship between stress and strain on the one hand and the pressure and height of the bulge on the other hand was established as a function of the Poisson's ratio and the crystal symmetry.

91 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated the influence of preferred orientation on the processes of strain localization which lead to necking failure in biaxial stretching in sheets of copper, aluminium and low-carbon steels.
Abstract: Influences of preferred orientation on the processes of strain localization which lead to necking failure in biaxial stretching have been investigated in sheets of copper, aluminium and low-carbon steels. With copper having a 0.94 volume fraction of {100}(001) oriented grains, groove formation appeared to be essentially in accord with the predictions of bifurcation theory. However, with more usual sheet textures the effects of preferred orientation on biaxial limit strains depended on the distribution and intensity of plastic inhomogeneities in the microstructure. For copper with a strong {110}(112) textural component, it was shown that crystallographically directed groove formation in biaxial stretching was associated with the large difference in TaylorM factors for plane strain with extension in a (100) direction and for biaxial extension in directions perpendicular to (110). More generally, it was found that the distribution of different components of a texture in the microstructure, and the relative TaylorM factors of segregated components, can have important effects on the rate at which strain localization develops. It was concluded that statistical averages of the distribution of orientations do not provide a sufficient basis for prediction of the effects of preferred orientation on limit strains in biaxial stretching.

55 citations


Journal ArticleDOI
TL;DR: In this paper, a specific influence of crystailographic texture on tensile properties of the titanium alloy VT6 under superplastic flow conditions is described. And the effect of texture on the anisotropy of properties of VT6 alloy is examined on alloy states with identical microstructures but with different preferred grain orientations.
Abstract: This paper describes a specific influence of crystailographic texture on tensile properties of the titanium alloy VT6 under superplastic flow conditions. The texture effect has been examined on alloy states with identical microstructures but with different preferred grain orientations. Tests over wide temperature and strain-rate intervals have shown that the formation of a strong texture as a result of pretreatment of a titanium alloy leads to a decrease in flow stress, an increase in plasticity and a shift of the optimum strain-rate region to higher rates. Data on the effect of texture on the anisotropy of properties of the VT6 alloy are also presented. The present results suggest that the influence of preferred orientation on the characteristics of superplastic flow is a general phenomenon for finegrained superplastic materials.

30 citations


Journal ArticleDOI
W. Tolksdorf1, I. Bartels1
TL;DR: The formation of yttrium iron garnet layers with thicknesses of 1 to 8 μ m was studied by liquid phase epitaxy using polished spheres of gadolinium gallium garnet single crystals of 2 to 8 mm diameter as substrates as discussed by the authors.

29 citations


Journal ArticleDOI
01 Jan 1981-Carbon
TL;DR: In this paper, the carbon-carbon composites made from ex-acrylic fibers and pyrocarbon matrices have been characterized by optical and electron microscopy, showing that upon heat treatment of the composite, the isotropic texture undergoes some reorganisation particularly in the vicinity of curved interfaces.

28 citations


Journal ArticleDOI
TL;DR: In this article, the authors show that the ultrasonic wave velocity depends on the stress as well as on the strain dependent second-order elastic coefficients, and demonstrate that wave propagation in stressed materials is fundamentally different from the stress-free case with related symmetry.
Abstract: Abstrucr-The application of ultrasonics to the nondestructive evaluation of residual stresses has been hindered by the question of whether the wave velocity is actually stress or strain dependent and by the confusion of the stress/strain related anisotropy with that due to orientation texture. The ultrasonic wave velocity is shown to depend on the stress as well as on the strain dependent second-order elastic coefficients. This separate dependence on stress and strain is demonstrated with the aid of a mathematical model used to find the effect of finite strain on the wave velocities. The direct stress dependence of the ultrasonic velocity reflects the fact that wave propagation in stressed materials is fundamentally different from the stress-free case with the related symmetry. A comparison of wave speeds for materials with isotropic, transversely isotropic, cubic, or tetragonal symmetry, and these same materials under uniaxial strain are presented to indicate how to separate the effects of stress and texture. This information has application to finding the longitudinal force in continuously welded rail and the residual stresses in unidirectional metal matrix composites.

25 citations


Journal ArticleDOI
TL;DR: The main body of the present work is a summary of the extensive account in Ref. 1 to which we have to refer the reader for most of the details as mentioned in this paper, and additional material is being included where explicitly stated.
Abstract: The main body of the present work is a summary of the extensive account in Ref. 1 to which we have to refer the reader for most of the details. Additional material is being included where explicitly stated.

23 citations


Patent
05 Feb 1981
TL;DR: In this paper, the specific electrical resistance, ρ, is determined as a function of layer thickness, d, and layering parameters are regulated by a process-control computer, where factors effecting the growth of a layer with respect to its structure, texture and composition are identified and calculated as measured values of ρ and d. In this manner, the nucleation and its growth is influenced in such a manner that the layer exhibits the desired electrical, structural and texture properties in its final state.
Abstract: Reproducible manufacture of metallic layers for semiconductor and thin film technology is attained by dynamic control of the layering process whereby the specific electrical resistance, ρ, is determined as a function of layer thickness, d, and layering parameters are regulated by a process-control computer. With this process, factors effecting the growth of a layer with respect to its structure, texture and composition are identified and calculated as measured values of ρ and d, by the process-control computer and corrections for individual layering parameters are calculated via a suitable control program. In this manner, the nucleation of a layer and its growth is influenced in such a manner that the layer exhibits the desired electrical, structural and texture properties in its final state.

22 citations



Patent
27 Nov 1981
TL;DR: In this article, a processing sequence is described for producing specific controlled elongated oriented crystal structures in nickel base superalloys in a solid-state process, where the material is cold straight rolled and cold cross-rolled with intermediate anneals.
Abstract: A processing sequence is described for producing specific controlled elongated oriented crystal structures in nickel base superalloys. The method is performed in the solid state. Superalloy material is provided in a dense workable form. The material is cold straight rolled and cold cross rolled with intermediate anneals. This sequence produces a particular texture or preferred orientation in the rolled article. This textured article is then directionally recrystallized to produce the desired final microstructure comprised of aligned elongated grains of a particular controllable orientation.

Journal ArticleDOI
TL;DR: In this paper, the flow stress was measured on recrystallized zinc with pronounced texture for grain sizes from 0,6 to 502 μm, both parallel and perpendicular to the rolling direction.

Journal ArticleDOI
TL;DR: In this paper, the Bauschinger effect in Zircaloy-2 has been investigated at room temperature using specimens cut from the L and ST directions of a thick, rolled slab, and specimens machined from swaged rods.

Journal ArticleDOI
01 May 1981-Fuel
TL;DR: In this article, the authors examined the optical texture of polished surfaces of cokes and related changes in surface topography caused by gasification by carbon dioxide at 1173 K, by heat treatment to 2073 k and by etching with atomic oxygen at 293 k.

Journal ArticleDOI
TL;DR: In this article, the microstructure and texture of injection-moulded plaques of an acetal copolymer were determined by polarized light microscopy and X-ray pole-figure analysis, respectively.
Abstract: Processing conditions, microstructure and mechanical property correlations have been explored in injection-moulded plaques of an acetal copolymer. Barrel temperature was varied systematically between 453 and 503 K, with a constant mould temperature of 343 K. The microstructure and texture were determined by polarized light microscopy and X-ray pole-figure analysis, respectively. The overall structure of the mouldings was layered through the thickness and symetrical about the moulding centre line. At all barrel temperatures five layers were present: the outer three layers possessed significant preferred chain-axis orientation in the crystalline phase, while the two layers at the centre of the moulding were equiaxed. The texture and morphology of each layer is described and related to a model of mould filling. Increases in the barrel temperature reduced the extent of the outer oriented layers while increasing the extent of the equiaxed layers. Tensile tests were conducted on samples taken at 0° and 90° to the injection direction. Increases in barrel temperature had no influence on modulus but decreased both (α=0 and 90°) engineering yield stresses. The yield stress could be correlated with the extent of the oriented layers within mouldings. At all barrel temperatures the yield stress was greater when α=90°; this behaviour is explained in terms of a composite model.

Journal ArticleDOI
TL;DR: In this paper, the growth and orientation of thin films of silver on glass were studied by means of reflection high energy electron diffraction under ultrahigh vacuum conditions and in the presence of argon and oxygen.

Journal ArticleDOI
TL;DR: Instrumental measures of textural properties and texture panel evaluations were obtained on several meat products irradiated using various dose-temperature conditions as mentioned in this paper, and the panel results and the instrumental data revealed several irradiation treatments that produced a tougher meat than the nonirradiated controls.
Abstract: Instrumental measures of textural properties and texture panel evaluations were obtained on several meat products irradiated using various dose-temperature conditions. Both the panel results and the instrumental data revealed several irradiation treatments that produced a tougher meat than the nonirradiated controls. Further studies indicated this toughening was due to a freezing-irradiation interaction.

Journal ArticleDOI
TL;DR: In this paper, a theory is proposed to explain the behavior of the initial magnetization curves I(H) of polycrystalline grain-oriented ferromagnetic materials by taking into account the properties of transverse closure domains lowering the magnetostatic energy of samples.
Abstract: A theory is proposed to explain the behavior of the initial magnetization curves I(H) of polycrystalline grain‐oriented ferromagnetic materials by taking into account the properties of transverse closure domains lowering the magnetostatic energy of samples. The effects due to the collapse of these domain structures with increasing H are shown to be of relevance in determining the actual shape of the I(H) curve in the intermediate field region 5×102 A/m≲H≲104 A/m, both in the absence and in the presence of applied stresses. The results of measurements of I(H) in Fe‐Si sheets with high texture perfections are reported. These results are in very good agreement with the present theory. Finally, a new method is proposed to obtain information on either the grains dispersion in grain‐oriented materials or on the volume of the transverse domains by performing only magnetic measurements.

Journal ArticleDOI
TL;DR: In this article, transmission electron microscopy (TEM) and X-ray structural analysis were used to investigate the structural characteristics of polycrystalline nickel electrodeposits of different thicknesses and with a unique texture.

Journal ArticleDOI
01 Jan 1981-Carbon
TL;DR: In this paper, the effects of the process variables (acetylene concentration in argon and gas flow rate) on both the solids yield and relative proportions of the various types of pyrolytic carbon were estimated.

Journal ArticleDOI
TL;DR: In this paper, the odd part of the texture function from the null domains of experimental pole figures has been determined from a theoretical texture function of a gaussian type; then, the method has been applied to determine the complete texture functions of a rolled copper sample.
Abstract: 2014 In a recent letter a method was proposed how to determine the odd part of the texture function from the null domains of experimental pole figures [3]. In order to prove the validity of this method, numerical calculations have been done from a theoretical texture function of a gaussian type; then, the method has been applied to determine the complete texture function of a rolled copper sample. J. Physique LETTRES 42 (1981) L-141 L-144 15 MARS 1981, Classification Physics Abstracts 81.40E The orientation distribution function ODF of crystallites in a polycrystalline sample can be calculated from experimental pole figures by a series expansion method [1] In the case of centrosymmetric crystals or by virtue of Friedel’s law [2, 3] the odd part of this series f a(g) does not contribute to the experimental pole figures. Hence, it cannot be determined from pole figure measurements as can the even part f S(g). Nevertheless, there may be some information on the odd part contained in pole figures, if the pole figures and hence the ODF contain zero ranges Zoo From the general positivity condition

Journal ArticleDOI
TL;DR: In this article, the use of surface waves in studying the spatial variation of texture within austenitic weld metal has been discussed and compared with X-ray pole figures for several different weld structures and for cast material.
Abstract: Austenitic weld metal exhibits an epitaxially developed columnar grain structure which is elastically highly anisotropic. Ultrasonic inspection of such waves has proved difficult because of the directional variability of the velocity and attenuation of elastic waves. Beam skewing, bunching, and spreading take place. If the texture within the weld varies strongly from point to point, it is likely that the reliability of conventional inspection methods will also vary. The purpose of this paper is to outline the use of surface waves in studying the spatial variation of texture within austenitic weld metal. Rotated surface acoustic wave velocities have been measured and compared with X-ray pole figures for several different weld structures and for cast material. Pole figures obtained from an austenitic butt weld reveal that it processes a strong 〈200〉 preferred orientation with the [200] axis parallel to the columnar grain axis, but with isotropic behaviour around this axis. Macroscopically, the weld ...

Journal ArticleDOI
TL;DR: The texture of previously-studied copper of grain sizes 3.4, 15 and 150 µ m has been measured, and compared to copper either mechanically processed to randomize texture, or cast in an equiaxed condition as discussed by the authors.
Abstract: The texture of previously-studied copper of grain sizes 3.4, 15 and 150 µ m has been measured, and compared to copper either mechanically processed to “randomize” texture, or cast in an equiaxed condition. Work-hardening behavior was also determined for the latter two types of material. The 3.4 µ m material was found to be very weakly textured, yet its stress-strain curve differed considerably from the Taylor-predicted curve based on a single crystal. More strongly fiber-textured material, such as the 150 µ m material, and also the weakly-textured cast material of 405 µ m grain size, agreed much more closely with the Taylor prediction. It was concluded that any texture effects on work hardening in copper are overwhelmed by grain size effects.

Journal ArticleDOI
TL;DR: In this article, single and double-layer thin-film anti-reflection (AR) coatings have been designed and applied to CdS/Cu2S solar cells.
Abstract: Single and double‐layer thin‐film anti‐reflection (AR) coatings have been designed and applied to CdS/Cu2S solar cells. A variety of materials, such as SiOx, Ta2O5, TiOx, ZnS, MgF2, and SiO2 have been deposited by sputtering and vacuum deposition, both reactive and nonreactive. The absorptance of the resulting AR films was found to be less than 0.01 for practical film thicknesses. Total cell reflectance, measured with a Gier–Dunkle SP 220 integrating sphere, as well as light‐generated current data were used to optimize the AR coating design and deposition. Optical losses were found to be weakly dependent on the AR material or design and strongly dependent on Cu2S texture. The results are analyzed in terms of a simple planar multilayer model.

Journal ArticleDOI
TL;DR: In this article, the authors consider the theory of ultrasonic propagation in textured materials and compare this with the experimental evidence and find that the effects of texture mask the more important effect of stress.
Abstract: For many years it seemed both convenient and accurate to ignore metallurgical texture in carrying out practical non-destructive testing. That this was a false simplification was shown up dramatically in recent studies of the austenitic weld. Large variations in ultrasonic attenuation were encountered in these welds which are now ascribed almost entirely to the effects of texture. These observations reopen the question of texture effects in other materials, such as rolled steel plate, which are known to have modest degrees of grain alignment. Is it still possible to assume that these materials are isotropic without introducing significant errors? The author considers the theory of ultrasonic propagation in textured materials and compares this with the experimental evidence. In addition, another problem where the effects of texture mask the more important effect of stress is mentioned. These discussions pay regard to work on practical, in addition to laboratory, specimens.

Journal ArticleDOI
TL;DR: In this article, four lots of stress-relieved Zircaloy-2 tubing were prepared from a single heat of the alloy and tube reduction parameters were controlled so that each lot had a different crystallographic texture.
Abstract: Four lots of stress-relieved Zircaloy-2 tubing were prepared from a single heat of the alloy. Tube reduction parameters were controlled so that each lot had a different crystallographic texture. The tubing with the most radial (least tangential) basal pole intensity was shown to have a Kearns texture number in the radial direction of 0.61, whereas the equivalent value for the tubing with the least radial texture was 0.48. Each lot of tubing was given one of three surface treatments: etched, etched and grit blasted, or lightly etched and shot blasted. The iodine stress corrosion cracking (SCC) susceptibility of the unirradiated tubing was determined by measuring the time to failure in a standard tube pressurization test at about 593 K in which 6 mg of iodine was present for each square centimetre of exposed Zircaloy surface. The results showed that texture has a large effect on SCC susceptibility and that surface condition has a significant but lesser effect. The SCC resistance was lowest in the material with the most tangential basal pole intensity and increased as the texture became more radial. The lightly etched and shot-blasted surface resulted in times to failure that were shorter than the times for the othermore » two surface conditions. However, it seems likely that the influence of surface treatment is quite complex and that SCC susceptibility can change significantly with a seemingly minor change in the surface treatment technique. The effect of texture was interpreted in terms of its influence on strength, on deformation characteristics, and on orientation of SCC susceptible planes with respect to the dominant tensile (hoop) stress. The effect of surface condition was interpreted in terms of its influence on residual stresses, on local texture changes, on local stress concentration, and on chemical activity.« less

Journal ArticleDOI
TL;DR: In this article, the influence of H 2 O 2 on the crystalline orientation of thin PbS films obtained by chemical deposition on glass substrates was investigated by using X-ray diffraction.

Patent
20 Nov 1981
TL;DR: In this paper, the shape memory of a Cu-Zn-Al alloy was used to obtain a single crystal of the titled alloy having a large amount of shape memory, causing no intergranular cracking, by passing it through a furnace in the atmosphere of air at a fixed speed.
Abstract: PURPOSE:To obtain a single crystal of the titled alloy having a large amount of shape memory, causing no intergranular cracking, by providing a Cu-Zn-Al alloy material having shape memory with a given strain, passing it through a furnace in the atmosphere of air at a fixed speed. CONSTITUTION:A Cu-Zn-Al alloy having shape memory is melted, forged, rolled, so that the casting texture is destroyed. The alloy is annealed at about 700- 750 deg.C to remove the strain, to give a uniform alpha+beta texture free from internal strain. The alloy material is provided with about 1-3% strain again, and it is removed. The alloy material is drawn up from the low-temperature side to the high-temperature side through an electric furnace having a temperature gradient in the atmosphere of air so that it is heat-treated gradually. A crystal grain starts to grow with the rise in temperature, the phase of the crystal grain is changed into the phase of the crystal simultaneously with the enlargement of the crystal grain and it becomes a single beta grain shortly. The pulling is stopped at this stage, it is kept for about 30-60min as it is, the subgrain is removed, it is made into a solution, to give a single crystal material of alloy having shape memory.

Journal ArticleDOI
TL;DR: In this paper, a preponderance of ⟨110⟩ crystallographic axes parallel to the incident beam develops during irradiation but the intensity of the effect is dependent on the ion species in an apparently unpredictable way.
Abstract: Vacuum-deposited Cu specimens were implanted with 40 keV Cu+, Ni+, Ne+, Kr+ and Xe+ ions in an electromagnetic isotope separator. The specimens were investigated for texture by X-ray diffraction techniques on implanted as well as non-implanted areas of the same specimen. It was found that a preponderance of ⟨110⟩ crystallographic axes parallel to the incident beam develops during irradiation but that the intensity of the effect is dependent on the ion species in an apparently unpredictable way. A previously suggested channelling mechanism for the origin of the effect is discussed in the light of the present findings and it is concluded that modifications to the proposed mechanism is needed to accommodate these results. It is further shown that certain implications of the results presented here could have an important bearing on ion bombardment related phenomena such as ion ranges, sputtering and materials modification by ion implantation.

Journal ArticleDOI
TL;DR: In this article, the authors investigated the changes in liquid-crystal light transmission caused by temperature variations in connection with texture changes and showed that planar texture appears in a heating process but the focal conic texture in a cooling process.
Abstract: The changes in liquid-crystal light transmission caused by temperature variations are investigated in connection with texture changes. Materials under investigation are the nematic-cholesteric and the smectic-cholesteric mixed liquid crystals. In the nematic-cholesteric mixed liquid crystal, the light scattering centers produced by the temperature variation from the liquid phase to the cholesteric phase cannot disappear with the applied voltage of 1 kHz. On the contrary, the light scattering centers produced in the dynamic scattering mode can disappear with the applied voltage of 1 kHz. In the cholesteric phase of a smectic-cholesteric mixed liquid crystal, the planar texture appears in a heating process but the focal conic texture in a cooling process. This texture difference causes the difference in the light transmission between the heating and the cooling processes. Further, the difference in the light transmission of a planar texture depends on the mesh area: as the area is larger, the trans...