bluuebunny/crossref_metadata_2025 huggingface dataset:
AN APPROACH TO TESTING BLACK-BOX COMPONENTS USING CONTRACT-BASED MUTATION
Authors: JIANG YING , HOU SHAN-SHAN , SHAN JIN-HUI , ZHANG LU , XIE BING
Published: April 2008

Component Based Software Development (CBSD) is gaining popularity in recent years. In this way of software development, software components, which are typically black-box components, are intensively reused to construct new systems. To ensure the quality of software systems composed of black-box components, a primary concern is how to ensure the quality of black-box components. Thus, adequate testing of those black-box components that will be reused is a necessary step in CBSD. However, due to the unavailability of the source code of black-box components, ensuring test adequacy becomes one of the hardest issues for testing black-box components. To tackle this problem, it is a natural idea to apply mutation testing, which is a fault-based testing method used for measuring test adequacy, for component contracts, whose aim is to improve the testability of the component. Though powerful, mutation testing is usually very computation-expensive, as many mutants need to be produced and executed in mutation testing. In this paper, we propose a contract-based mutation technique for testing black-box components. Based on the discordance between contracts and specification, our approach employs a set of high level contract mutation operators. The experimental results show that these operators can greatly reduce the number of mutants compared with traditional mutation operators. At the same time, the contract-based mutation using our contract mutation operators can provide almost the same ability as that of using traditional mutation operators. Therefore, our approach can produce effective test suites to reduce the cost of testing black-box components.
A COMMERCIAL OFF-THE-SHELF IMPLEMENTATION OF AN ANALOG NEURAL COMPUTER
Authors: BODDHU SANJAY K. , GALLAGHER JOHN C. , VIGRAHAM SARANYAN A.
Published: April 2008

For most applications, analog electrical circuit implementations of continuous-valued neural networks have been abandoned in favor of digital simulations. This is not surprising, as both precision and accuracy can be more easily ensured in digital computers. Still, because they use far fewer transistors and support components, analog circuits can still be orders of magnitude smaller than their digital simulations. In some application, like micro-robotics and embedded control, one might be willing to tolerate less accuracy and precision for the size and power benefits. One would not under any condition, however, tolerate significant behavioral mismatches between the differential equation and electrical circuit forms of the neural networks in question. In this paper, we will present a design for an analog neural computer that embodies the commonly used continuous time recurrent neural network. We will show that the computer possesses excellent behavioral congruence to the differential equation form even in the presence of significant practical compromises. We will also discuss the implications of this work for both practical Commercial, Off-The-Shelf (COTS) and Application-Specific Integrated Circuit (ASIC) devices.
PREPROCESSING QUANTIFIED CONSTRAINT SATISFACTION PROBLEMS WITH VALUE REORDERING AND DIRECTIONAL ARC AND PATH CONSISTENCY
Authors: STERGIOU KOSTAS
Published: April 2008

The Quantified Constraint Satisfaction Problem (QCSP) is an extension of the CSP that can be used to model combinatorial problems containing contingency or uncertainty. It allows for universally quantified variables that can model uncertain actions and events, such as the unknown weather for a future party, or an opponent's next move in a game. Although interest in QCSPs is increasing in recent years, the development of techniques for handling QCSPs is still at an early stage. For example, although it is well known that local consistencies are of primary importance in CSPs, only arc consistency has been extended to quantified problems. In this paper we contribute towards the development of solution methods for QCSPs in two ways. First, by extending directional arc and path consistency, two popular local consistencies in constraint satisfaction, to the quantified case and proposing an algorithm that achieves these consistencies. Second, by showing how value ordering heuristics can be utilized to speed up computation in QCSPs. We study the impact of preprocessing QCSPs with value reordering and directional quantified arc and path consistency by running experiments on randomly generated problems. Results show that our preprocessing methods can significantly speed up the QCSP solving process, especially on hard instances from the phase transition region.
HAPLOTYPE INFERENCE WITH BOOLEAN SATISFIABILITY
Authors: LYNCE INÊS , MARQUES-SILVA JOÃO
Published: April 2008

Mutation in DNA is the principal cause for differences among human beings, and Single Nucleotide Polymorphisms (SNPs) are the most common mutations. Hence, a fundamental task is to complete a map of haplotypes (which identify SNPs) in the human population. Associated with this effort, a key computational problem is the inference of haplotype data from genotype data, since in practice genotype data rather than haplotype data is usually obtained. Different haplotype inference approaches have been proposed, including the utilization of statistical methods and the utilization of the pure parsimony criterion. The problem of haplotype inference by pure parsimony (HIPP) is interesting not only because of its application to haplotype inference, but also because it is a challenging NP-hard problem, being APX-hard. Recent work has shown that a SAT-based approach is the most efficient approach for the problem of haplotype inference by pure parsimony (HIPP), being several orders of magnitude faster than existing integer linear programming and branch and bound solutions. This paper provides a detailed description of SHIPs, a SAT-based approach for the HIPP problem, and presents comprehensive experimental results comparing SHIPs with all other exact approaches for the HIPP problem. These results confirm that SHIPs is currently the most effective approach for the HIPP problem.
KINETICS OF MIGRATION AND COALESCENCE OF SUPPORTED NM-SIZED METAL PARTICLES
Authors: ZHDANOV VLADIMIR P.
Published: April 2008

Monte Carlo simulations of the kinetics of migration and coalescence of nm-sized metal particles on a uniform surface and a surface with traps in the physically reasonable case when the diffusion coefficient of particles varies inversely as the fourth power of the particle size are presented. The Monte Carlo kinetics are demonstrated to be in good agreement with the mean-field results. The size distribution of particles is found to be nearly symmetrical with respect to the average value.
COMPARATIVE STUDY OF Fe–C–H INTERACTION NEAR LINE AND POINT DEFECTS IN IRON STRUCTURES
Authors: SIMONETTI S. , BRIZUELA G. , JUAN A.
Published: April 2008

The Fe – C – H interaction near defects in iron structures was studied using qualitative structure calculations in the framework of the atom superposition and electron delocalization molecular orbital. Calculations were performed using three Fe clusters to simulate an edge dislocation, a divacancy; both in bcc iron and a stacking fault in an fcc iron structure. In all cases, the most stable location for C atom inside the clusters was determined. Therefore, H atom was approximated to a minimum energy region where the C atom resides. The total energy of the cluster decreases when the C atom is located near the defects zone. In addition, the presence of C in the defects zone makes no favorable H accumulation. The C acts as an expeller of H in a way that reduces the hydrogen Fe – Fe bonds weakening.
LASER PERCUSSION DRILLING ON THIN MILD STEEL SHEET BASED ON THE DUTY CYCLE VARIATIONS OF A PULSED RF SLAB CO2 LASER
Authors: CORTES R. , VILLAGOMEZ R. , LOPEZ R. , COELLO V.
Published: April 2008

In this work, the influence of laser pulse trains on thin mild steel sheet blades is investigated. The method is based on varying the duty cycle (DC) of a pulsed RF slab CO 2 laser during the process of laser percussion drilling. Here, an experimental methodology to correlate laser parameters and their effects on the characteristics of the melting material ejected was carried out. In the experiments, the interaction time such that of 5%, 10%, and 15% DC were considered for the pulse trains. Results showed a significant effect on the characteristics of melt material ejection during laser percussion. We demonstrate that it was not evident the influence and molten material for pulse width of less than 500 μs and larger than 4500 μs, respectively, when having 5% DC; spatter formation (droplets) for 10% and 15% DC with pulse periods > 2000 μs; debris formation (re-solidified material) at pulse periods from 200 to 1250 μs at 15% DC.
BARIUM TITANATE FILMS FOR ELECTRONIC APPLICATIONS: STRUCTURAL AND DIELECTRIC PROPERTIES
Authors: RIAZ S. , SHAMAILA S. , KHAN B. , NASEEM S.
Published: April 2008

Synthesis of the precursors, using research grade materials and locally available facilities, is optimized in order to obtain a suitable sol for BaTiO 3. The optimally synthesized BaTiO 3 sol is then spun onto Cu substrates to obtain films of thickness ~0.5 μm. The deposited BaTiO 3 films are heated up to a temperature of 300°C. Surface and structural changes, with heating, are observed by optical microscope, scanning electron microscope, atomic force microscope, and X-ray diffraction. The surface cracked in some cases but is generally uniform, as seen with SEM and AFM, in case of optimized conditions. The SEM images reveal large crystallites, which are correlated to the XRD observation of tetragonal perovskite structure of these sol–gel films. The AFM scan, however, shows an rms roughness of 35.6 nm for an area of 3 μm × 3 μm. Tetragonal perovskite BaTiO 3 is obtained at a temperature of as low as 300°C. The dielectric constant and loss angle, in the 30 Hz–3 MHz range, are calculated at room temperature and up to 200°C. At high frequencies the dielectric constant (~290) and loss angle (~2 × 10-6) values indicate the usefulness of such films in electronic applications. The leakage current is also measured at room temperature and a conductivity of 2.0 × 10-15 S/cm is obtained.
THE Fe ULTRATHIN FILM ON ZnO(000-1) SURFACE: GROWTH, STRUCTURE, AND INTERACTION
Authors: WANG GUO-DONG , XU FA-QIANG , ZHANG WANG , ZHANG WEN-HUA , LI ZONG-MU
Published: April 2008

We report the electronic structure of the interface of the ultrafilm Fe film with the O -terminated ZnO (000-1) polar surface studied by synchrotron radiation photoemission. It was found that Fe grows in a Stranski–Krastanov mode. The turning point of the growth mode was at the Fe coverage of ~2 Å. At low coverage, about 1 ML (monolayer) of iron (ca. 1.5 Å) was oxidized by the terminative oxygen atoms on the ZnO (000-1) surface. Analysis of the valence band and the Fe 3 p photoemission spectra indicates that below 2 Å coverage, only Fe 2+ species could be detected at the Fe / ZnO interface, after that the formation of a metallic iron overlayer was observed. A sharp Fermi edge appeared at 5.1 Å coverage, indicating the formation of the bulk metallic Fe film. Furthermore, work function of the sample decreased to a minimum of 4.5 eV at 0.2 Å Fe , and then to 4.9 eV with the formation of a dipole layer at the interface.
HYDROGEN ADSORPTION AND DIFFUSION ON A Pt(111) CLUSTER
Authors: MARCHETTI J. M. , GONZÁLEZ E. , JASEN P. , BRIZUELA G. , JUAN A.
Published: April 2008

The interaction of hydrogen with a platinum (111) cluster using the atom superposition and electron delocalization–higher binding ASED-TB quantum calculation method was studied. The metal surface was represented by a Pt cluster of seven layers. The effect of hydrogen on this metal substrate was studied by the analysis of density of states and crystal orbital overlap populations curves. The energy surface plots allow us to find a possible diffusion path through the cluster from one side to the other. The Pt – Pt metal bond is weakened during H adsorption and diffusion. The main components in the Pt – H bond are the Pt 6s (31%), 6p (26%), and 5 d xz (16%) orbitals.
Earing in Deep‐Drawing Steels
Authors: Davies G. J. , Goodwill D. J. , Kallend J. S.
Published: April 2008

The variations of the fourth‐order coefficients of the crystallite orientation distribution function, with rolling reduction have been determined after cold‐rolling and annealing for a deep‐drawing quality rimming steel and an aluminium‐killed steel. These coefficients influence drawability and earing behaviour and by the manipulation of
the coefficients in the distribution function of a 60% cold‐rolled and annealed rimming steel, a hypothetical non‐earing sheet texture has been derived. By comparison with the actual sheet texture those textural components which most affect earing behaviour are identified.
Oriented Nucleation in Low‐Carbon Steels
Authors: Every R. L. , Hatherly M.
Published: April 2008

The preferred orientations in hot‐rolled, cold‐rolled (70 % reduction), and annealed low‐carbon steels (capped and aluminium‐killed grades) have been investigated. Particular attention has been paid to the factors that control texture formation during annealing.The elastic energy stored in the cold‐rolled steels is orientation dependent and the sequence, estimated from a Fourier analysis of X‐ray line broadening, is V110 > V111 > V211 > V100; the values range from 3.51 to 1.14 cal/g atom. The high energy components ({110}, {111}) have elongated cell structures but those of lower energy are equiaxed. In capped steels the high energy components recover and recrystallize most rapidly. In aluminium‐killed
steels both recovery and recrystallization are inhibited at low temperatures ≤ 500℃ and recrystallization begins first in the {111} components. It is shown that these effects are associated with precipitation and/or segregation of AlN during recovery. The recrystallization texture is determined primarily by oriented nucleation.
The Development of Rolling Texture in α‐Brass Determined by Neutron Diffraction
Authors: Tobisch J. , Mücklichf A.
Published: April 2008

The three‐dimensional orientation distribution was calculated from neutron diffraction pole figures for a copper 27.2% zinc alloy cold rolled to different degrees of deformation. The results agree qualitatively with those of other authors. There are however differences in the quantitative respect which influence the conclusions to be
drawn. For rolling degrees lower than about 70% the texture exhibits an orientation tube similar to that of the
copper type, but with a significantly different distribution along the tube axis. For rolling degrees larger than 70%
the texture can be described by the orientation {110}〈112〉. The deformation is assumed to occur according to the Wassermann model and the Hu model respectively in these two ranges.
Description of Orientation Distributions of Cubic Crystals by Means of 3‐D Rotation Coordinates
Authors: Ibe Gerhard , Lücke Kurt
Published: April 2008

A method has been described to represent orientations and orientation distributions of cubic crystals by means of
a 3‐dimensional orientation space which is formed by the repeatedly discussed rotation coordinates (axis and
angle of rotation). Special emphasis has been given to the problem of multi‐valency of the representation due to
the cubic symmetry, to the description of scattering around an ideal orientation and to the numerical evaluation
of these orientation coordinates by means of rotation matrices.
An Improvement of Vector Method by Allocation of Intensities Based on the Crystallographic Symmetry
Authors: Shimizu R. , Ohta K. , Harase J.
Published: April 2008

An investigation has been carried out utilizing model and experimental pole figures
made by X‐ray technique in order to examine the use of the vector method as a
means of the texture analysis. The main findings are as follows:

• From crystal symmetry considerations positions and magnitudes of peaks along
the ζ
angle can be predicted. There are discrepancies in these intensity peaks
and in some cases the peaks are missing altogether.

• This problem was solved by the allocation of intensities such that equal
intensities are obtained at the crystallographic symmetry positions.

• Even a slightly mismatched combination of the reflection and transmission pole
figures caused an increase in residual vector (R) resulting in the failure of the
analysis for the minor textural component.
An Investigation Into the Accuracy of the Vector Method by Comparison With ECP Measurements
Authors: Shimizu R. , Harase J. , Ohta K.
Published: April 2008

In an attempt to investigate the accuracy of the vector method for crystal texture
analysis, a comparison has been made between the inversion result of the pole figure
made by X‐ray studies using the VM and the inversion result of the pole figure made
by ECP. A comparison has been made between the inversion by the pole figure
generated by direct measurement of orientations by ECP and the actual orientation
distribution (measured by ECP) displayed in the same mode. The materials studied
were recrystallized Fe–3% Si and Fe–50% Ni. The main findings were:

• In the mean intensities of each individual Box, the inversion results of pole
figures made from orientations determined by ECP were in good agreement with
the inversion from (100) pole figures made by X‐ray or actual orientation
distribution (made by ECP) displayed in the same mode as the vector method.

• For Fe–3% Si, quite a good agreement was obtained between the results
inverted from X‐ray pole figure and the direct measurement by ECP for the
intensity distribution of minor texture component along ζ angle. It was
concluded from these investigations that the inversion of the pole figure by the
vector method is accurate enough for most practical purposes.
Model Calculations of Elastic Moduli in Highly Deformed Composites
Authors: Bunge H. J.
Published: April 2008

Young′s modulus of heavily deformed two‐phase composites shows an unusually high
increase after plastic deformation. It is assumed that this is due to two reasons, i.e.
texture changes and changes of the moduli of the constitutive phases on the basis of
non‐linear elasticity theory and internal stresses of opposite sign in the phases.
Expressions of the two contributions are given on the basis of simple model
assumptions. It is estimated that the changes of shape and arrangement of the phases
and shape and arrangement of the crystallites in the phases are only of minor
importance.
Crystal Rotations Represented as Rodrigues Vectors
Authors: Becker R. , Panchanadeeswaran S.
Published: April 2008

Rodrigues vectors are explored as a means of representing crystal orientation
distributions. Relationships between the Rodrigues vectors and several more
commonly utilized representations of rotations are presented. The restrictions which
cubic material symmetry imposes on the Rodrigues space are examined and
relationships for special equivalent configurations are developed. Common crystal
orientation distributions are presented as Rodrigues vectors and compared to the
more standard representations in terms of pole figures and Euler angles. Applications
of the Rodrigues space for illustrating misorientations between neighboring grains are also discussed.
Anomalous Scattering and Null‐Domain Ghost Corrections for Fibre Textures
Authors: Fuentes L.
Published: April 2008

The practical applicability of anomalous scattering and null‐domain ghost corrections
for fibre textures is theoretically evaluated. For a hypothetical asymmetric orientation
distribution of quartz‐like BPO4 highly absorpting crystals, slightly asymmetric
anomalous scattering pole figures are predicted. On the basis of projection relations
among orientation distribution functions and inverse pole figures, the special
characteristics of the null‐domain method for fibre textures are discussed, with the
suggestion of a practical procedure to estimate (in favourable cases) an upper limit
for ghosts effects.
Fast Texture Measurements Using a Position Sensitive Detector
Authors: Jensen Dorte Juul , Leffers Torben
Published: April 2008

A technique for fast texture determination by neutron diffraction is described. With
the technique a complete texture analysis requires from 15 to 45 minutes measuring
time and the kinetics of the development in single texture components can be studied
with a time resolution of the order of seconds. It is shown how these two measuring
principles can be used for in‐situ kinetic investigations of recrystallization. Independent
of speed, texture measurement by neutron diffraction has an advantage in
improved statistics which is examplified by a series of measurements on the early
stage of texture development in copper and brass.
Texture Analysis by Neutron Diffraction Using a Linear Position Sensitive Detector
Authors: Will G. , Schäfer W. , Merz P.
Published: April 2008

Neutron diffraction in connection with a position‐sensitive detector is a most
powerful technique in texture analysis comparable in time with conventional X‐ray
laboratory technique. Neutrons measure the global texture of the sample allowing
volumes up to several cm3. By using position‐sensitive detectors and applying the
mathematical procedures of profile analysis multiphase and low symmetry materials
can be investigated without serious difficulties. Neutron diffraction experiments
operating in transmission record complete diffraction profiles; overlapping lines are
unscrambled by profile analysis. Technical and physical specifications of the
dedicated detector JULIOS, installed on the texture diffractometer of Bonn
University, are given. A hematite ore has been studied by this technique and the
results are given.
Microstructure and Texture of Rolled (110)[001] Copper Single Crystals
Authors: Wróbel M. , Dymek S. , Blicharski M. , Gorczyca S.
Published: April 2008

The dislocation structure was free from inhomogeneities with high orientation
changes normally observed in deformed materials. After reductions 20% and 40%
against the background of cells there were sometimes observed bands (dislocation
rich layers). With increasing strain the cell structure became faint and the dislocation
rich layers became sharper (after 60% reduction no dislocation cells were revealed).
It has been found, that in layers lying close to the rolled surface of the specimen the
dislocation bands were nearly parallel to the RD and much thinner than those in
further layers. SAD analysis indicate that in the surface layers the crystallographic
orientation changed systematically with increasing distance from the surface to the
center of the specimen (rotation around ND). In the intermediate layers the
dislocation bands were curved and overlapped the other dislocation bands. Despite
of detailed investigation shear bands were not observed even in specimens rolled to
the 95% reduction.
Anisotropy of Magnetic Properties in Non‐oriented Electrical Steel Sheets
Authors: Shiozaki M. , Kurosaki Y.
Published: April 2008

The anisotropy of magnetic properties in non‐oriented electrical steel sheets can be evaluated by
measuring Epstein specimens in the radial directions. The magnetic properties measured on ring cores
are practically equal to the approximate values of magnetic properties determined by Epstein
specimens in the radial directions. Non‐oriented electrical steel sheets with anisotropy are not
desirable for motors but are suitable for transformers and fluorescent lamp ballasts. The core loss and
magnetic induction as measured with ring specimens are better with non‐oriented electrical steel
sheets with anisotropy than with non‐oriented electrical steel sheets with random crystallographic
orientation. This phenomenon depends on the texture change of the product.
Elastic Properties of Polycrystals: A Review
Authors: Hirsekorn S.
Published: April 2008

The elastic properties of polycrystals depend on the single‐crystal elastic constants of the crystallites
which build up the polycrystal and on the manner in which the crystallites are connected. Because of
the technical importance of polycrystalline materials a lot of papers deal with the problem to calculate
effective elastic constants of polycrystals from single‐crystal and structure properties. This paper gives
a review concerning the most important theories and methods respecting this matter.
Correlations Between the Rolling Textures in FCC Ni–Co Alloys and the BCC Transformation Textures in Controlled Rolled Steels
Authors: Ray R. K. , Chapellier Ph. , Jonas J. J.
Published: April 2008

Three fcc Ni–Co alloys with different stacking fault energies (SFE′s) were cold rolled 95% and their textures
were characterized by the orientation distribution function (ODF) method. BCC transformation
textures were calculated from these experimental textures using three different orientation
relationships for the γ → α transformation. The transformed ODF′s derived from the Bain
relationship were much sharper than the ones deduced from the Kurdjumov–Sachs (K–S) or the
Nishiyama–Wassermann (N–W) relations. The ferrite texture determined on a controlled rolled steel,
heavily deformed in the unrecrystallized γ region, agrees reasonably well with the bcc texture
calculated using the K–S relation from the rolled Ni–Co alloy with similar SFE. The major texture
components of the ferrite, namely {332}〈113〉 and {311}〈011〉, are found to originate from the two
major rolling texture components of the austenite, i.e. the {110}〈112〉(Bs) and {112}〈111〉(Cu),
respectively. Such ferrite transformation from heavily deformed austenite seems to follow the K–S
relationship without any variant selection. By contrast, the texture of the martensite produced from
deformed austenite appears to involve significant amounts of variant selection.
Development of Cross‐rolling Textures in AlMn1
Authors: Böcker A. , Klein H. , Bunge H. J.
Published: April 2008

True cross‐rolling and pseudo cross‐rolling (with only one change of the rolling direction after half of
the total deformation degree) was investigated in an alloy AlMn1 up to 93% deformation. The texture
formation was studied in terms of ODF. After true cross‐rolling (multi‐stage rolling) a strong
two‐component ideal orientation near (011)[322] was found with maximum densities up to 60 times
random. Pseudo cross‐rolling (two‐stage rolling) resulted in weaker, but still strong deformation
textures with maximum densities up to twenty times random which were intermediate between
unidirectional and true cross‐rolling textures. In both cases, the originally present cube texture
decreased continuously with increasing deformation degree.
Nondestructive Analysis of Textures in Rolled Sheets by Ultrasonic Techniques
Authors: Spies M. , Schneider E.
Published: April 2008

The preferred grain orientation in polycrystals causes a direction dependence of the ultrasonic wave
velocities. In an extensive study, the texture influence on different ultrasonic wave velocities is
measured in series of cold‐rolled ferritic steel sheets. Based on that, ultrasonic techniques are
developed to characterize the texture in terms of the three fourth‐order expansion coefficients of the
orientation distribution function (ODF). Evaluation equations are given for the application of free
ultrasonic longitudinal and shear waves as well as for the application of ultrasonic SH‐waves.

Furthermore, linear correlations are found between the Δr‐ and rm‐values, characterizing the deep drawability of the sheets and the expansion coefficients and , evaluated by ultrasonic techniques. The study demonstrates that ultrasonic techniques hold
high promise to evaluate the fourth‐order expansion coefficients of the ODF and to characterize the deep drawing behavior of
rolled sheets by the use of calibration experiments.
Development of Cube Texture in Coarse Grained Copper
Authors: Sindel M. , Köhlhoff G. D. , Lücke K. , Duggan B. J.
Published: April 2008

Cube oriented deformed material has been detected in the rolling texture measured on edge sections
of heavily rolled coarse grained copper. The level of intensity is low, and seems to be independent of
rolling reduction over the range 93–98%. Recrystallization textures show an increasing strength of
Cube with rolling reduction. The evidence is consistent with the idea that Cube nuclei are created by
a mechanism similar to that proposed by Dillamore and Katoh, and the strength of the recrystallized
Cube texture depends on oriented growth. Prior grain size effects are briefly examined and it is shown
that deformation textures are less sharp in large grain size compared with small grain sized copper at
similar strains. It is likely that the effect of grain size on cube texture formation arises from grain size
dependent texture changes in the vicinity of the deformed Cube oriented material.
Lower Bound Yield Locus Calculations
Authors: Hosford William , Galdos Aitor
Published: April 2008

A lower‐bound model for the deformation of work‐hardening polycrystals is proposed. All grains are
assumed to be loaded under the same stress and the stress–strain behavior is found by averaging the
strains in all grains. The shapes of the yield loci have been calculated for textured metals which
deform by {111} 〈110〉 slip (fcc) and by 〈111〉‐pencil glide (bcc). As with the corresponding
upper‐bound models, the yield loci are best described by an anisotropic yield criterion with an
exponent of 6 to 10 (instead of 2 as in the Hill theory). Also it is shown that a model of polycrystal
deformation in which the grains are loaded to the same stress ratio (but not the same level of stresses)
violates normality and is not a lower bound.
Directionally Solidified Materials:Nickel‐base Superalloys forGas Turbines
Authors: Lacaze Jacques , Hazotte Alain
Published: April 2008

From the first forged turbine blades made of iron base alloys to the present nickel base single‐grain
turbine blades and vanes manufactured by directional solidification, an enormous amount of research
has been directed to attaining the hottest possible combustion chamber temperatures in jet engines.
Temperature has been increased by about 15 K each year for the last two decades, improving the
thermodynamic efficiency of the engines. The more recent developments concern the manufacturing
of single‐grain parts made of nickel base superalloys with large amount of the γ′ hardening phase.

This paper first presents the directional solidification process used to produce single‐grain parts, the
formation of as‐cast microstructures and the defects that can arise during solidification. In the second
part the thermal treatments that are applied to the nickel base superalloys in order to enhance their
mechanical properties are detailed. The effect of crystallographic orientation and of the γ/γ′
microstructure on the mechanical properties is briefly presented, as well as the. microstructural
changes that can possibly arise during service.
Texture and Strength Evolution inDeformed Polypropylene
Authors: Hirsch J. R. , Wang P. T.
Published: April 2008

Semicrystalline polypropylene samples with high concentrations of crystallinity (≳62%) are deformed
in uniaxial compression at different temperatures and different strain rates. The orientation changes of
the crystalline part of the material are analyzed using X‐ray diffraction methods. Pole figure
evaluation is used to obtain information about the crystal structure, the geometry of slip, and its
correlation with the characteristic of strength evolution in polymers. The contribution of the
crystalline part of the material to plastic flow is estimated and the textures are related to the
characteristic effects in plastic and visco‐elastic response of the material during deformation and
subsequent stress relaxation. The observed texture effects can be explained by the rotation of
crystallographic c‐axis (backbone axis) normal to the compression direction at high temperatures in a
planar slip mode. The stress/strain and relaxation behavior of the material is interpreted as a
combination of viscoelastic flow of amorphous volume and irreversible plastic flow of the crystalline
part which contributes to an orientation dependence of deformation and stress relaxation.
Automated Determination of LatticeOrientation From ElectronBackscattered KikuchiDiffraction Patterns
Authors: Wright Stuart I. , Zhao Jun-Wu , Adams Brent L.
Published: April 2008

As described in a previous paper (Wright and Adams, 1990), with the advent of new techniques it has
become practical to consider using single orientation measurements for texture investigations.

Advantages of using single orientations measurements over the traditional bulk measurement using
pole figures are: direct access to odd‐l terms in the series expansion of the Orientation Distribution
Function (ODF) (Bunge, 1982) and the capability to measure local textures and to obtain spatial
orientation correlation information. The primary obstacle to the use of single orientation measurements
is the large investment of direct operator time required to obtain a statistically reliable data set.
This study examines a technique that has been developed to automate the orientation identification
process. The technique essentially compares an electron backscattered Kikuchi diffraction (BKD)
pattern with a set of idealized patterns and finds the best match. The set of idealized patterns is
created from a set of orientations which represent a tessellation of the asymmetric region of Euler
space. The technique shows promising preliminary results, BKD patterns for silicon and stainless steel
were correctly identified by the computer.
Effects of Deposition Conditions onTexture in Copper ThinFilms on Si (111)
Authors: Knorr D. B. , Lu T.-M.
Published: April 2008

The texture of copper films deposited on bare Si (111) is studied using a partially ionized beam
deposition technique. A change in deposition parameters (percent ions and substrate bias) radically
alters the texture from epitaxial to fiber. Under conditions indicative of deposition by evaporation, a
sharp texture typified by a Cu {531} ‖ Si (111) relationship is observed. At measurable ion energy
levels, the film texture becomes Cu (111). A narrowly defined set of conditions promotes epitaxy
which breaks down into a fiber texture for conditions of successively higher ion energy. The role of
internal (boundary) energy and interfacial (substrate/film and film/ambient) energy are discussed.
Resolution of SuperimposedDiffraction Peaks in Texture Analysisof a YBa2Cu3O7 Polycrystal
Authors: Kallend John S. , Schwarz R. B. , Rollett A. D.
Published: April 2008

Texture measurements in polycrystalline 123 oxide superconductors are complicated by the superposition
of Bragg reflections in the pole figures due to the near degeneracy of the crystal structure. A
method is described, based on an extension of the WIMV algorithm, for resolving these
superpositions and determining the crystal orientation distribution (OD). The method is exemplified
by OD analysis of a magnetically aligned, strongly textured powder sample of YBa2Cu3O7.
A Method for the Generation ofVarious Ghost CorrectionAlgorithms—the Example of thePositivity Method and the ExponentialMethod
Authors: Van Houtte P.
Published: April 2008

A theoretical strategy is presented that can derive the algorithms of several existing ghost correction
methods. The examples of the positivity method and the “GHOST” method are elaborated. A new
method is derived as well: the “exponential” method. It can successfully replace the quadratic method
as a method that yields an exactly non‐negative complete C.O.D.F. from pole figure data. The
theoretical scheme that can generate all these algorithms makes use of the fact, that several parameter
sets can be defined in order to describe a C.O.D.F. The parameters of one set are then functions of
those of the other. The algorithms are derived from Taylor series expansions of these functions.
Texture Evolution in a Hot RolledAustenitic Stainless Steel
Authors: Singh C. D. , Ramaswamy V. , Suryanarayana C.
Published: April 2008

The ODF analysis of the surface texture of the hot band of austenitic stainless steel reveals the
presence of orientations of shear texture. These orientation elements are mainly distributed along two
limited tubes of preferred orientations. The fibre of the first tube has its axis 〈110〉 ‖ RD and runs
from {001} 〈110〉 to an orientation near {112}〈110〉 whereas the fibre of the second tube is inclined
30° from ND towards RD (i.e. 〈110〉 30° ND fibre) and stretches from {111}〈112〉 + 5° to the
orientation near {112}〈110〉. The shear texture components are formed at the surface by shearing
during hot rolling. Once they are formed, they get partly recrystallized by dynamic in situ
recrystallization. On the other hand a duplex texture (i.e. retained copper type and recrystallization
type) is present at the centre level of the hot band. The orientation elements of copper type (i.e.
〈110〉 60° ND fibre) are {011}〈112〉, ≈ {123}〈634〉 and {112}〈111〉 whereas the recrystallization
texture components are dominated by cube {001}〈100〉 orientation and other RD rotated cubes
through oriented nucleation during dynamic recrystallization.
The Compound Influence of Textureand Microstructure on theMechanical Properties of Low‐C SteelWires
Authors: Gangli P. , Szpunar J. A. , Sugondo
Published: April 2008

A series of experiments were made determining textural, microstructural, and mechanical properties
in cold drawn, and spheroidization heat treated low‐C steel wires (AISI‐1018 and 1033 grades). It was
found that texture exerted a significant influence on the mechanical properties, while microstructure had a comparable influence.

Mechanical properties are represented by yield strength (YS), ultimate compressive strength (UCS)
and by homogeneous strain energy (EHOM), defined by the integral of stress up to uniform
elongation. Textural properties are represented by the Taylor‐factor, M, the R‐value, and by the
maximum of the orientation distribution function (ODFMAX). Micro‐structural properties are
treated with the help of the aspect ratio parameter (1/√AR), where AR is the grain aspect ratio
(length to ellipsoidal width), the grain size parameter (1/√D), and the mean free path between second phase spheroidized cementites √N.

For cold drawn steel wires, homogeneous strain energy (EHOM) is well correlated to (1/√AR) and
(ODFMAX). Yield strength, on the other hand, appears to be chiefly influenced by the aspect ratio
parameter, thus here ODFMAX exerts less influence. The yield strength (YS) of annealed,
spheroidization treated low‐C wires are equally influenced by the grain size parameter (1/√D), the
mean distance between spherulites (√N) and by ODFMAX.

The textures of the cold drawn wires could be well described by the 〈110〉 fibre parallel to wire axis, and by the 〈111〉 fibre normal to wire axis. The annealed wires, while also featuring these two fibres, displayed a distinct {111}〈110〉single orientation.
A Theoretical Analysis of EquibiaxialDeformation Texture UnderNon‐prescribed Strain Path
Authors: Lee W. B. , Chan K. C.
Published: April 2008

A model is presented to calculate the rotation path of crystals under equibiaxial tension when the
strain ratio is fixed (prescribed strain path) or when the strain ratio is allowed to adjust itself according
to the external constraint and the current state of the plastic anisotropy of the material (nonprescribed
strain path). It is found that the stability of grain orientation is related to the curvature of
the strain path. There is a difference in the predicted equibiaxial deformation texture for the two types
of strain paths. Grain orientations which are unstable under a linear strain path may become stable
under a non‐linear or varying strain path.
Parameterizations and ProbabilityDistributions of Orientations
Authors: Schaeben H.
Published: April 2008

General normal distributions of orientations (proper rotations) with respect to different parameterizations
are mathematically rigorously and notationally concisely represented. This includes their explicit
formulations as well as their characterizations in terms of maximum entropy and their explict one–one
correspondence.
Texture Investigations at LowTemperatures by NeutronDiffraction Shown on theExample of TbAg
Authors: Elf F. , Schäfer W. , Höfler S. , Will G.
Published: April 2008

The first low temperature texture investigation by neutron diffraction is presented. Pole figures are
collected on a special full circle Eulerian cradle mounted completely inside a helium cryostat. Nuclear
and magnetic pole figures of antiferromagnetic TbAg are measured at 300 and at 77 K respectively.
The bulk specimen revealed only a weak texture. Magnetic satellite reflections presumed for special
sample orientations were not observed.
Model Calculations of ContinuousGrain Growth in Textured Materials
Authors: Bunge H. J. , Dahlem-Klein E.
Published: April 2008

Continuous grain growth of a polycrystalline structure proceeds by the simultaneous movement of all
grain boundaries driven by the grain boundary energy and controlled by the boundary mobility. In the
present model calculations, energy and mobility are allowed to depend on the orientation difference
between neighbouring crystals. The growth process then depends on the misorientation distribution
function. In a first approximation the orientation correlations are assumed to be random. Then the
MODF can be expressed by the texture. A simple growth model leads to a continuity equation
depending on crystal orientation g and grain radius r which can be integrated for the steady state case
in which the texture and the shape of the grain size distribution curve remain constant. The same
solution also serves as an approximation for pseudo‐steady state cases with slowly varying texture.
More general solutions are obtained by adding several pseudo‐steady state solutions. The specific case
of two pseudo‐steady state components is considered in detail. Thereby the growth kinetics, texture
changes and the form of the grain size distribution curves is obtained.
Earing Control and Deformation Processing of Aluminium Alloys
Authors: Lequeu Ph.
Published: April 2008

The production of ear free aluminium flat rolled products highly depends on the ability to balance the deformation and recrystallization textures at the final gauge. A
model based on the concept of earing diagram is proposed, which enables the process‐texture‐earing relationships to be assessed in a fairly simple way. It is shown that such a predictive tool can be used for the definition of optimized fabrication schedules leading to ear free material. Such earing control is achieved by a control of both the microstructural evolution as well as the position of the recrystallization steps along the complete fabrication sequence.
Model Calculation of Cross Rolling Textures
Authors: Klein H. , Esling C. , Bunge H. J.
Published: April 2008

Model calculations of texture formation during cross‐rolling are carried out based on the full–constrained Taylor theory. Three variants of cross–rolling were considered i.e. two–stage, four–stage and multi–stage
rolling. Three types of glide systems {110}〈111〉, {112}〈111〉, {123}〈111〉 and all possible combinations of them were compared.
The calculations were based on calculated orientation changes for grid points throughout the orientation space, taking the spread range according to the non–unique solution of the Taylor theory into account.
The calculation were carried out in terms of the texture coefficients
. The best agreement between experimental and
calculated orientation densities was obtained with {123}〈111〉
glide
systems.
Texture and Plastic Anisotropy in Model Aluminium ‐ Lithium Alloys
Authors: Engler Olaf , Mizera Jaroslaw , Driver Julian H. , Lücke Kurt
Published: April 2008

The specific roles of Li, Zr and Cu alloying elements
in Al‐Li alloys have been investigated in terms of their
influence on texture evolution during rolling and
subsequent plastic anisotropy. Three model alloys; Al‐2.3%
Li, Al‐2.3% Li‐0.1% Zr and Al‐2.3% Li‐1.2% Cu‐0.1% Zr were
hot and cold rolled to reductions up to 92% and their
texture evolution systematically characterised by X‐ray
pole figures and complete ODFs. Hot rolling of the Zr
containing alloys, which do not recrystallize, led to a
strong Bs texture component. Cold rolling of all alloys
gave the usual Taylor‐type β fibre components, with certain
variations according to the precipitation state which can
favour or inhibit shear banding.

Pronounced plastic anisotropies, R(α), were measured
on the rolled sheets with Rmin at α = 0° and Rmax at α ≈ 60°. Actual values depend upon rolling temperature and strain
but typically Rmin ≈ 0.3 and Rmax ≈ 1.5 to 2. The
quantitative texture data was used together with the CMTP
and Taylor models to predict the anisotropy; in general the
CMTP model gave a reasonable correlation with the
experimental values.
Texture and Anisotropy of Plastic Properties in Deep Drawing Steels
Authors: Daniel D. , Jonas J. J.
Published: April 2008

The textures of different types of deep drawing steels were measured
and analyzed using the series expansion method. The angular variation of r‐value
in the rolling plane was calculated from the ODF coefficients by
means of different models. Comparison with experimental data shows that,
in the case of sharp textures, an intermediate relaxed constraint model
(pancake version) is a better predictor of the plastic strain ratio than the
extreme Taylor or Sachs‐Kochendorfer type calculation. This is justified as
being more favorable energetically for the texture components present in
deep drawing steels. The best quantitative agreement is obtained when the
CRSS ratio for glide on the {112}<111> and {110}<111> slip systems is
0.95 (except for the AKDQ and IF2 grades, for which values of 0.90 and 1.0,
respectively, are preferred).
Anisotropic Plastic Behavior Associated With Rolling Textures
Authors: Darrieulat M. , Montheillet F.
Published: April 2008

The overall plastic response of a sheet can be simply
calculated from the knowledge of its various texture
components, the behavior of them being described by the
equations of continuum plasticity. It is shown, however,
that the classical assumptions used for combining the
elementary components can lead to significantly different
predictions of the sheet behavior.
Recrystallization Experiments in Tensile Deformed <100>‐Oriented Single Crystals of Copper‐Phosphorusand Copper‐Manganese Alloys
Authors: Freye D. , Funke C. , Klement U. , Wilbrandt P.-J.
Published: April 2008

The recrysallization process in specimens of dilute
CuP and CuMn alloys was investigated to determine those orientation
relationships between recrystallized grains and deformation
microstructure, which favour rapid grain growth.
The specimens were prepared from tensile deformed <100>‐oriented
single crystals. In the CuP alloy the largest recrystallized
grains have near 20° <94,30,7> or 53° <73,63,25>
orientation relationships to the deformation microstructure.
In the CuMn alloy only the two orientation relationships
30° <73,56,39> and 48° <71,61,35> were found.
Reference ODF Calculations for the Torsion of FCC Rate Sensitive Polycrystals
Authors: Gilormini P. , Tóth L. S. , Jonas J. J.
Published: April 2008

analytic calculations are presented for the deformation induced ODF in a sheared FCC
polycrystal. The uniform strain (Taylor) hypothesis and the theory of rate dependent slip are
used. The fibre considered contains three interesting ideal orientations, and periodic ODF
variations are observed. The present predictions, which can be readily and rapidly obtained, are
useful for testing computer codes for the simulation of large deformation textures.
Effect of Local Texture on the Development of M‐K Groove in Biaxial Deformation
Authors: Lee W. B. , Can K. C.
Published: April 2008

The postulation of a groove defect is the cornerstone of
the Marciniak‐Kuczynski (M‐K) theory in the prediction of the
biaxial limit strains of sheet metals. Without the assumption of
an initial thickness inhomogeneity, such a groove is shown herein
to arise from texture colonies and its size predicted based on a
knowledge of the texture variation in commercial sheets.