bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Pre-Ageing and Addition of Copper on the Precipitation Behaviour in Al-Mg-Si Alloys
Authors: Morley A.I. , Zandbergen M.W. , Cerezo Alfred , Smith George D.W.
Published: March 2009

Hardness measurements and 3-dimensional atom probe analysis have been used to characterise the precipitation behaviour in two 6xxx series aluminium alloys, one Cu-free alloy (Al-0.78at%Mg- 0.68at%Si) and one Cu-containing alloy (Al-0.78at%Mg-0.68at%Si-0.30at%Cu). The heat treatments consisted of either natural ageing or pre-ageing at 353K followed by a paint-bake treatment at 453K. Natural ageing was seen to increase the hardness, and hence reduce formability compared to pre-ageing. In addition, the strengthening effect of artificial ageing was less after natural ageing than after pre-ageing. In the Cu-free alloy, needle-like β″ was observed to form only after a pre-ageing treatment during the first 60 minutes of a paint-bake treatment. In the Cucontaining alloy, needle-like β″ formed during paint bake in both the naturally-aged and pre-aged material, although it is formed more rapidly after pre-ageing. This was accompanied by an increase in strength over the Cu-free alloy and indicates that Cu reduces the deleterious effect of natural ageing.
Damage Tolerance Capability of an Al-Cu-Mg-Ag Alloy (2139)
Authors: Cho Alex , Bès Bernard
Published: March 2009

The effects of dispersoid forming elements on the mechanical properties of Al-Cu- Mg-Ag alloys are examined. It is found that a small amount of Zr addition is detrimental to the damage tolerance of Al-Cu-Mg-Ag alloys in artificially aged temper, while Mn addition is beneficial. The superior damage tolerance capability of Alloy 2139 is demonstrated by comparing it to other high performance alloys used for DT critical applications
Consequences of Hot Rolling of Recycled AA5050 on Filiform Corrosion
Authors: Premendra P. , Loven W. , Terryn H. , de Wit J.H.W. , Katgerman Laurens
Published: March 2009

The presence of a heavily deformed and corrosion susceptible surface/near-surface region
on rolled aluminium alloy has been amongst the most important problems which the aluminium
manufacturers are dealing with. While primarily the composition of the alloying elements and the
thermo-mechanical treatment play an important role in determining surface activation, the
importance of several other secondary parameters cannot be ignored. This paper tries to identify the
impact of several factors, associated with sheet metal production, on the corrosion behaviour e.g. (a)
type of the cast bar fed into the hot rolling mill, whether scalped or not scalped, (b) importance of
homogenisation and in-line heat treatment, in relation to pre-existing understanding of surface
activation on AA3005, (c) effect of hot and cold rolling (d) effect of surface finish, etc. The alloy
under investigation was recycled AA5050, containing high Fe and Si as impurities, and used
commercially for architectural purpose, eg. window facades.
Roughening of Coated Aluminium Sheets during Plastic Straining
Authors: Roters Franz , Raabe Dierk , Weiland Hasso
Published: March 2009

In this work we present deformation experiments of polymer-coated polycrystalline
aluminium sheets. We observe that the straining is accompanied by the development of
microstructural defects at the sample surface as well as in the interface between the metal and the
different polymers. These defects are due to a variety of dynamical mechanisms which are
essentially induced by bulk plasticity of the metal substrate. They micromechanically interact with
the polymer coating and transfer some of the metallic roughness to the coating and to the surface.
Investigation on Microstructure and Corrosion Behaviour of 6XXX Series Aluminium Alloys
Authors: Braun Reinhold
Published: March 2009

Microstructure and corrosion behaviour of 6061 and 6013 sheet material were investigated in the naturally aged and peak-aged heat treatment conditions. Transmission electron microscopy did not reveal strengthening phases in the naturally aged sheet. In the peak-aged temper, β’’ precipitates were observed in alloy 6061, whereas both β’’ and Q’ phases were present in 6013- T6 sheet. Marked grain boundary precipitation was not found. Corrosion potentials of the alloys 6061 and 6013 shifted to more active values with increasing aging. For the copper containing 6013 sheet, the potential difference between the tempers T4 and T6 was more pronounced. When immersed in an aqueous chloride-peroxide solution, alloy 6061 suffered predominantly intergranular corrosion and pitting in the tempers T4 and T6, respectively. On the contrary, 6013 sheet was sensitive to pitting in the naturally aged condition, and intergranular corrosion was the prevailing attack in the peak-aged material. Both alloys 6061 and 6013 were resistant to stress corrosion cracking in the tempers T4 and T6.
Precipitation and Mechanical Properties of Supersaturated Al-Zn-Mg Alloys Processed by Severe Plastic Deformation
Authors: Schiller I. , Gubicza Jenő , Kovács Zsolt , Chinh Nguyen Q. , Illy Judit
Published: March 2009

Supersaturated Al-4.8Zn-1.2Mg-0.14Zr and Al-5.7Zn-1.9Mg-0.35Cu (wt.%) alloys were
processed by Equal-Channel Angular Pressing (ECAP) at 200°C. The crystallite size distribution
and the characteristic parameters of the dislocation structure of both Al matrix and precipitates were
determined by X-ray diffraction line profile analysis, which has been complemented by
transmission electron microscopy (TEM) observations. The results show that severe plastic
deformation promotes the precipitation process and consequently has a strong influence on the
strength of these alloys.
Influence of Temperature and Strain Rate on the Plastic Deformation of Two Commercial High Strength Al Alloys
Authors: Johansson Magnus , Hörnqvist Magnus , Karlsson Birger
Published: March 2009

In the present study the influence of strain rate and temperature on the behaviour of two
commercial aluminium alloys, 6063-T6 and 7030-T6, was investigated. Both alloys are high
strength precipitation hardened alloys that are expected to have low strain rate and temperature
sensitivity. Tensile tests were performed at room temperature at strain rates ranging from 10-4 to 102
s-1, and at -40°C and +60°C at strain rates of 10-4 and 10-1 s-1, due to equipment limitations. Both
alloys showed low but positive strain rate sensitivity at all temperatures. Also the temperature
sensitivity was low, showing negative values in all cases. The dependence of the flow stress on
temperature was more pronounced than the strain rate dependence. The area reduction at fracture
was higher in 6063 than 7030, although the uniform elongation was larger in 7030. 6063 showed
almost no strain rate dependence of the ductility and a limited reduction with increased temperature.
7030 showed markedly increasing area reduction with increasing temperature and decreasing values
with increasing strain rate. The energy absorption was higher in 7030 by a factor of approximately
three.
Influence of Iron Content on the Mechanical Properties of AA6016 Alloy Sheet
Authors: Minoda Tadashi , Asano M. , Yoshida Hideo
Published: March 2009

The influence of the iron content from 0.1 to 1.0 mass% on the mechanical properties of AA6016-T4 sheets was investigated. The amount of the Al-Fe-Si second phase particles increased with the iron content, thus the solute silicon atoms decreased. Increasing of the Al-Fe-Si particles lowers the bendability, while decreasing of the solute silicon atoms lowers the paint bake response (PBR) and improves the bendability. The bendability of the samples then became the worst at the 0.5 mass% iron content, while it at 0.8 and 1.0 mass% became better or the same as that at 0.5 mass%. The increasing of the silicon content in the 1.0 mass% iron content alloy improved the PBR and lowered the bendability.
Investigation on Mechanism of Ductile Fracture of AA5754 Sheet
Authors: Kang Ji Dong , Wilkinson David S. , Embury J. David , Hussain Khalid
Published: March 2009

A number of mechanical tests and metallographic techniques have been used to investigate the mechanism of ductile fracture of AA5754 sheet. The sequence of events in the development of shear localization is clarified using in situ strain mapping on both the sample surface and through thickness direction during tensile tests. It is observed that the failure mode changes from cup-cone type to shearing with increasing Fe content in both continuous cast (CC) and direct-chill cast (DC) AA5754 sheets. However, this transition happens in CC with much lower Fe content than DC. As very little damage is found near the fracture surface, this suggests that damage may be a consequence of the shear process rather than a trigger that determines material ductility. For both CC and DC with same Fe content of 0.21%, fracture strain of CC is much lower than DC. It is postulated that this is due to the differences of particle distribution in these two materials, especially the increased fraction of stringer type structures which exist in CC material.
The Role of Alloy Composition on the Steam Oxidation Resistance of 9-12%Cr Steels
Authors: Osgerby Stephen , Fry A. Tony
Published: March 2009

Three commercial martensitic steels have been oxidised in steam at 600 and 650 °C for times up to 10000 h. The partition of minor elements within the oxide scales has been determined. Silicon forms an additional oxide layer beneath the spinel. Chromium, molybdenum and tungsten concentrate in the spinel and manganese is present in both the spinel and magnetite. Several proposed mechanisms for steam oxidation have been examined to explain the observed effects of alloy composition. Modification of the oxide defect structure and oxidant gas penetration through microcracks were identified as the mechanisms most able to explain the influence of alloy composition.
Fundamental Coating Development Study to Improve the Isothermal Oxidation Resistance and Thermal Cycle Durability of Thermal Barrier Coatings
Authors: Torigoe Taiji , Oguma Hidetaka , Okada Ikuo , Xu Guo Chun , Fujita Kazuhisa , Nakayama Akira , Maruyama Toshiro , Nishio Kazumasa
Published: March 2009

Thermal barrier coatings(TBCs) are used in high temperature gas turbines to reduce the surface
temperature of cooled metal parts such as turbine blades[1]. TBC consist of a bondcoat (e.g.
MCrAlY where M is Co, Ni, CoNi, etc.) and a partially stabilized zirconia ceramic topcoat.
Usually, the MCrAlY bondcoat is applied by LPPS (low pressure plasma spray) or HVOF(high
velocity oxi-fuel spray). The topcoat is applied by APS (atmospheric plasma splay) or EB-PVD
(electron beam-physical vapor deposition). High temperature oxidation properties, thermal barrier
properties and durability of TBC are very important to increase the reliability in high temperature
service. In this study, new TBC has been investigated. The new TBC consists of a two-layered
bondcoat (LPPS-MCrAlY plus dense PVD overlay MCrAlY) and the EB-PVD type YSZ columnar
structure topcoat. As a result of evaluation tests, it was confirmed that the new TBC had better
oxidation properties and durability than a conventional TBC system.
Interdiffusion Behavior of Electroplated Platinum-Iridium Alloys on Nickel-Base Single Crystal Superalloy TMS-82+
Authors: Wu Ying Na , Suzuki Aya S. , Murakami Hideyuki , Kuroda Seiji
Published: March 2009

In the present study, platinum-iridium alloys (Ir = 15.8, 27.3, 36.1, 100at.%) were electroplated on a nickel-base single crystal superalloy TMS-82+ followed by a diffusion treatment at 1373K for 1 h. Interdiffusion behavior between the Pt-Ir films and substrates was investigated in terms of chemical composition, phase constitution and morphology. X-ray analysis revealed that annealed specimens consisted of several fcc solid solutioned phases with various lattice parameters, together with ordered intermetallic compounds (L12-(Pt,Ni)3Al and B2-(Ir,Ni)Al), due to the inward diffusion of Pt and Ir from the electrodeposited films to the superalloy substrates, and the outward diffusion of solute elements (Ni, Al, Cr, Co) in the superalloy substrates into the films during annealing. The depth concentration analysis indicated that the Pt-36.1Ir film effectively retarded the outward diffusion of solute elements, especially nickel, from the substrate.
Oxidation Behavior and Scale Properties on the Si Containing Steels
Authors: Takeda Mikako , Onishi Takashi
Published: March 2009

The adhesion and micro-structure of the primary scale formed in LNG combustion gas on steels containing Si, up to 3.0mass%, have been studied using a hot-compression test at 1273K, Raman spectroscopy, and X-Ray absorption fine structure analysis (XAFS). The Fe2SiO4 at the scale/steel interface is increased as the Si content increases, suppressing the diffusion of Fe ions from the steel and forming dense and highly-adhesive subscale, when oxidized below the temperature at which the Fe2SiO4 melts. The behavior of the secondary scale growth in air up to 1173K on these has been studied using in-situ XRD. It is apparent that the formation behavior of Fe2SiO4 ,FeO and Fe2O3 is influenced by the Si content.
Hot Corrosion Monitoring of Waste Incineration Corrosion Processes Using Electrochemical Techniques
Authors: Pérez F.J. , Nieto J. , Trilleros J.A. , Hierro M.P.
Published: March 2009

In order to evaluate the damage of molten salt mixtures in waste incineration environments,
the alloy 625 was exposed to a molten KCl-ZnCl2 mixture at 650 °C for 200 hours. The corrosion
process was monitored by electrochemical impedance spectroscopy (EIS). After exposure the
corrosion products were analyzed by X-ray diffraction and SEM. Two different electrochemical
impedance models were found to describe the electrochemical processes. In the early stages of
corrosion the alloy developed a protective Cr2O3 scale which turned into a porous spinel oxide
scale after 100 hours.
Oxidation Rate of Magnesia-Carbon Refractory with Aluminum Additive
Authors: Sunayama Hiroyuki , Kawahara Masayasu
Published: March 2009

An effect of addition of 2 mass % aluminum powder on the oxidation rate of
magnesia-carbon refractory, MgO-C, containing 5 mass % carbon has been investigated by
measuring weight change with a thermobalance for the cubic specimens in the temperature range
from 1073 to 1823 K in air. The oxidation rate of carbon was measured by analyzing the residual
carbon in the specimens at some oxidation time. The variations of the weight with oxidation time at
temperatures from 1273 to 1673 K showed the similar tendency. The oxidation rate of carbon in the
MgO-C refractory with 2 mass % of aluminum additive was a little smaller than that of the MgO-C
refractory with no additives. When the oxidation temperature increased to 1823 K, the weight
change became very small. It was suggested that the gaps between MgO grains in the thin oxidation
layer were bridged by MgO·Al2O3, which was identified by a X-ray diffraction method.
White Beam Microdiffraction Experiments for the Determination of the Local Plastic Behaviour of Polycrystals
Authors: Castelnau Olivier , Goudeau Philippe , Geandier G. , Tamura Nobumichi , Béchade Jean Luc , Bornert M. , Caldemaison D.
Published: March 2009

The overall plastic behavior of polycrystalline materials strongly depends on the
microstructure and on the local rheology of individual grains. The characterization of the strain and
stress heterogeneities within the specimen, which result from the intergranular mechanical
interactions, is of particular interest since they largely control the microstructure evolutions such as
texture development, work-hardening, damage, recrystallization, etc. The influence of
microstructure on the effective behavior can be addressed by physical-based predictive models
(homogenization schemes) based either on full-field or on mean-field approaches. But these models
require the knowledge of the grain behavior, which in turn must be determined on the real specimen
under investigation. The microextensometry technique allows the determination of the surface total
(i.e. plastic + elastic) strain field with a micrometric spatial resolution. On the other hand, the white
beam X-ray microdiffraction technique developed recently at the Advanced Light Source enables
the determination of the elastic strain with the same spatial resolution. For polycrystalline materials
with grain size of about 10 micrometers, a complete intragranular mechanical characterization can
thus be performed by coupling these two techniques. The very first results obtained on plastically
deformed copper and zirconium specimens are presented.
An X-Ray Diffraction Method to Determine Stress at Constant Penetration/Information Depth
Authors: Kumar A. , Welzel U. , Wohlschlögel M. , Baumann W. , Mittemeijer Eric Jan
Published: March 2009

A rigorous strategy for (X-ray) diffraction stress measurements at fixed
penetration/information depths is described. Thereby errors caused by lack of penetration-depth
control in traditional (X-ray) diffraction (sin2ψ) measurements are annulled. The ranges of
accessible penetration/information depths and experimental aspects are briefly discussed. The power
of the method is illustrated by the analysis of an only small stress gradient in a sputter-deposited
nickel layer.
Dynamic Analysis of Residual Stress Introduced by Laser Peening
Authors: Akita Koichi , Kuroda Masatoshi , Withers Philip J.
Published: March 2009

Residual stress induced by laser single pulse irradiation was analyzed using a dynamic
finite element code, ABAQUS/Explicit. The effects of the magnitude and length of a surface pressure
pulse having a circular top-hat shape on the final residual stress in Ti-6Al-4V were investigated. A
high peak pressure and/or a long pulse duration was effective in generating large compressive residual
stress deep beneath the surface. However, large tensile residual stress features occurred near the
centre and edge of the laser spot on the surface for high pressure and/or long pulse durations due to a
radial focusing effect. Use of shorter pulse durations avoided this. The peak pressure (3GPa) required
to induce a surface compressive residual stress across the whole area of the spot was slightly higher
than the threshold pressure needed to plastically deform the surface.
X-Ray Diffraction in Failure Analysis of Rolling Bearings
Authors: Nierlich Wolfgang , Gegner Juergen , Brückner Mandy
Published: March 2009

By X-ray diffraction (XRD) measurements, material conditions of rolling bearings are
red that point to a variety of load possibilities especially at raceway surfaces. Due to unambiguously
distinguishable damage symptoms, according to H. Muro, it is differentiated between the surface
and sub-surface failure mode in the literature. Surface distress of different intensity can be generated
by particle-contaminated lubricants that result in raceway indentations. These micro-Hertzian
contacts may lead to changes in residual stress and line broadening and in the microstructure. Another
cause of surface distress is boundary lubrication. Relevant position and nature of the failure
mechanisms are characterized. In case of initial material stabilization, the time alterations of the
XRD parameters correlate with the statistical parameter of the 10 % bearing life. Contrary to the L10
value for sub-surface fatigue, which leads to spalling only a long time after incipient material softening,
in the surface damage mode the L10 life roughly coincides with the beginning of the instability
phase. Surface pitting or gray staining turns up frequently with low XRD indication of material
aging. Here, scanning electron microscopy and electron microprobe analysis point to corrosion
fatigue. The interaction between material and lubricant opens research in the field of tribology.
Relaxation of Residual Stresses in and around Mechanical Fasteners Due to Fatigue Loading
Authors: Fox Matthew E. , Withers Philip J.
Published: March 2009

The residual stresses around clearance-fit mechanical fasteners have been found to be
similar to those around cold expanded holes where compressive hoop stresses close to the fastener
hole are balanced by far-field tensile stresses. This compressive zone has been shown to prolong
fatigue lifetimes around fastener holes. Constant amplitude fatigue loading was applied to single
plate rivet specimens for varying numbers of cycles to investigate the redistribution of these stresses
after fatiguing. Synchrotron diffraction was used to map the evolution of the residual stresses
around the rivets. Little change in the hoop stress local to the rivets occurred until visible fatigue
cracks were observed suggesting that relaxation of these stresses is due to the cracks rather than
their cause.
E7 - New Strain Scanner at HMI - High Q-Resolution for Phase-Sensitive Analysis of Stress Distributions
Authors: Henkel Florian , Hermeking-Goebel Ulrike , Lemke Peter , Wilpert Thomas , Pietsch Christian , Schneider Rainer
Published: March 2009

A large distance between the reactor core and the monochromator together with a take-off
angle of 90° leads to low flux but high angular resolution of the diffractometer around 90° scattering
angle. The sample-table consists of two goniometers for heavy loads. An x-y-z table for heavy loads
can be mounted, as well as different eulerian cradles, a mirror furnace or a tensile rig. The detector
is a 20x20cm2 position sensitive delay-line detector made by EMBL. A sophisticated primary and
secondary slit system together with the recently installed high-resolution camera system allows the
application of the high precision instrument alignment and calibration system recently developed at
HMI. Here some special features of the instrument are presented and the consequences are outlined.
Sub-Surface Residual Stress Gradients: Advances in Laboratory XRD Methods
Authors: Azanza Ricardo Cristy Leonor , D'Incau Mirco , Scardi Paolo
Published: March 2009

A new algorithm is proposed to determine the through-thickness residual stress gradient by X-ray Diffraction measurements on progressively thinned components. The procedure is based on a chemical or electrochemical attack of the component surface, which is then measured at each thinning stage. The simple algorithm provided for by a specific norm has been revised to take into account the X-ray absorption effects and the conditions of mechanical equilibrium of the component. The new procedure is illustrated for a typical case of study concerning a shot-peened metal component.
Determination of Residual Stress Fields with High Local Resolution
Authors: Hasse Bernd , Koçak Mustafa , Reimers Walter
Published: March 2009

The non-destructive and phase selective determination of residual stresses caused by
material processing (such as welding) in polycrystalline samples is usually performed by diffraction
methods. In order to obtain information about stress fields at high spatial resolution with
conventional methods, for example with micro beam techniques, the sample needs to be scanned in
a very time consuming manner. A much faster method is the simultaneous investigation of a larger
area using position sensitive diffractometry. This method was used for the analysis of the residual
stress distribution in laser beam welded thin (2 mm and 3 mm) magnesium sheets.
Finite Element Simulation of the Residual Stress States after Shot Peening
Authors: Klemenz Manuel , Schulze Volker , Vöhringer Otmar , Löhe Detlef
Published: March 2009

In a three-dimensional Finite-Element-Simulation of shot peening, a combined isotropickinematic
viscoplastic material description was introduced in order to describe the cyclic softening
effects during peening. After verifying the model in the simulation of push-pull tests at different
strain amplitudes it could be used for the shot peening simulation. The simulated residual stress
profile is compared with experimental results determined by X-ray diffraction and with simulated
results of a simpler isotropic viscoplastic material model.
Numerical Simulation of Residual Stresses during the Heat Treatment of Dies Made of Hot Work Tool Steel
Authors: Redl Christian , Friesenbichler Christian , Wieser Volker
Published: March 2009

Residual stresses are of great importance during the entire production cycle of high-grade
steels. The use of modern tools based on the finite element method is steadily increasing to optimize
heat treatment processes. As for industrial purposes it is often not possible to measure the entire set
of material data a sensitivity analysis shows the relative influence of material properties related to
phase transformation on the residual stresses during hardening. Subsequently the application of the
numerical heat treatment model is shown on two examples: The magnitudes of residual stresses
during the quenching of a forged bar in different quenching media are compared. The paper
concludes with a numerical simulation of the heat treatment of a die used for extrusion processes.
Phase distribution and residual stresses after gas quenching of the tool are presented.
Effect of Grain Size Distribution on Second Order Stresses in Plastically Deformed Polycrystals
Authors: Berbenni Stephane , Berveiller Marcel
Published: March 2009

The overall behaviour of metals composed of grains with different sizes is simulated as
well as the evolution of their internal structure making use a self-consistent modelling for elasticviscoplastic
materials. The Representative Volume Element is composed of isotropic spherical
grains randomly distributed with a grain size distribution following a log-normal statistical
function. Thus the heterogeneity of the RVE comes only from the grain size dependence of the
local flow stress. The viscoplastic strain rate of the grains is modelled through a classic isotropic
power law involving a reference stress depending on the individual grain size and the local plastic
strain. Numerical results applied to IF steels firstly display that the overall yield stress depends not
only on the mean grain size but also on the dispersion of the grain diameter distribution. The role of
the grain size dispersion becomes significant when the mean grain size is on the order of "m, and, a
decrease of the overall yield stress with an increase of the dispersion is observed. Secondly,
prediction of the evolution of the internal structure indicates an increase of second order internal
stresses with grain size dispersion. When this one is large enough and the mean grain size is on the
order of "m, residual stresses due to heterogeneities arising from the grain size distribution are on
the same order than the ones related to heterogeneities associated with plastic anisotropy found for
polycrystalline IF steels.
Numerical Simulation of Residual Stresses at the Grain and Sub-Grain Length Scale Using Atomistic Modeling
Authors: Rentsch Rüdiger , Brinksmeier Ekkard
Published: March 2009

For modeling the deformation and the heat treatment related change of micro structural
material properties, a crystal structure with several grains is analyzed using the molecular dynamics
simulation. The generated atom arrangement has been equilibrated, sheared and tempered, and the
resulting microstructures and stresses as well as their changes are presented. The shearing of the
multiple grain model into the region of plastic deformation caused a significant change in its
microstructure and introduced additional stress. On applying the heat treatment simulation, it was
possible to show thermally induced relaxation processes in a microstructure using MD.
Application of Hole-Drilling Method in Practice
Authors: Podgornik Bojan , Vižintin Joze , Kopač Franci
Published: March 2009

Residual stresses can arise in engineering components as part of their manufacturing or can also be introduced deliberately as part of surface treatment procedures. A precise knowledge of the level of residual stresses that exist in engineering components is necessary in analysis and quality control as well as for accurate prediction of components lifetime. Therefore, reliable methods of determining the magnitude and distribution of residual stresses are required in order to quantify their effect and to avoid detrimental failures. On the other hand on-site portable and nonor near non-destructive methods are required for practical use. The hole-drilling method shows a great potential in measuring and evaluating residual stresses in practical applications. This paper presents results and problems on residual stress measurements performed by the holedrilling method on real components, including forming applications of rolling, punching and cutting, and machine component applications of gears and shafts. Presented results clearly indicate the importance of residual stress information for proper design and use of engineering components.
Residual Stresses Gradient Determination in Cu Thin Films
Authors: Peng Jun , Ji Vincent , Zhang Jian Min , Seiler Wilfrid
Published: March 2009

The non-destructive analysis by GIXRD allows us to determine the residual stress
distribution as a function of XRD penetration depth and film thickness. A new development
on the determination of residual stresses distribution is presented here. The procedure, based
on the GIXRD geometry (referred to here as the ‘sin2ψ*’), enables non-destructive
measurement of stresses gradient with only one diffraction family plan at a chosen depth
taking into account the correction of measured direction. The chosen penetration depth is well
defined for different combination of ψ and Φ and needs not to be changed during
experimentation. This method was applied for measurement of residual stress gradient in Cu
thin films. The obtained residual stress levels and their distribution were quite comparable
with those determined by another multi-reflection method.
Residual Stresses Induced by Cross-Rolling
Authors: Wierzbanowski Krzysztof , Wroński Sebastian , Baczmanski Andrzej , Wróbel Mirosław , Braham Chedly , Fitzpatrick Michael E. , Lodini Alain
Published: March 2009

Deformation by rolling induces in general a strong crystallographic texture, hence an
important material anisotropy. This is a reason why the cross-rolling is sometimes applied in order
to symmetrize the crystallographic texture. Such an operation modifies also residual stresses. The
goal of this study was to characterize residual stress and texture changes during simple and crossrolling
in polycrystalline copper and ferritic steel. The obtained results show that important
modification of the first order residual stresses occurs during cross-rolling, while the level of the
second order ones is approximately constant. Experimental results were analysed using an elastoplastic
deformation model.
Strain Scan and Texture of an Anhydrite-Dolomite Rock from the Piora-Syncline (Switzerland)
Authors: Scheffzük Christian , Walther Kurt , Frischbutter Alexander , Naumann Rudolf
Published: March 2009

An anhydrite-dolomite rock was investigated in order to find correlations between
intracrystalline strain and texture. The sample represents a composite rock, called Zuckerdolomit,
occurring for instance in the central Alps. Zuckerdolomit may occasionally respond to mechanical
impulses with a complete break down of its structure. Residual strain was scanned at the
strain/stress diffractometer EPSILON-MDS and the crystallographic texture was obtained by
neutron time-of-flight diffraction at the texture diffractometer SKAT at the pulsed neutron source
IBR-2 in Dubna, Russia. Texture was additionally determined by the U-stage microscopy.
The texture of the rock could be derived from the main constituents: anhydrite and dolomite. The
anhydrite texture appears to be characterised by an orthorhombic symmetry. One plane of the
symmetry trends parallel to the rock’s foliation plane, with basal planes subparallel to and a small
circle distribution within the foliation plane. There is a subordinated small circle orientation pattern
relating in 45° to the rock’s foliation plane. On the other hand, the subordinated regulation pattern
of anhydrite is fixed to the orientation of the foliation plane. The determined residual strain data for
anhydrite and dolomite reflect a generally opposed directed state, regarding both, compression and
dilatation. Moreover, taking into account the elastic constants for both minerals, which differ
approximately by the factor two, the special geomechanical behaviour of the studied Zuckerdolomit
appears to be considerably determined by interactions between its residual strain and textural
properties. This may be of particular importance for underground activities (mining, tunnelling etc.).
The dangerous geomechanical behaviour of the rock seems to be determined by its residual straintexture
relations more than so far believed (anhydrite hydration).
Residual Stress Measurements in Single and Multi-Pass Groove Weld Specimens Using Neutron Diffraction and the Contour Method
Authors: Kartal M. , Turski Mark , Johnson Greg , Fitzpatrick Michael E. , Gungor S. , Withers Philip J. , Edwards Lyndon
Published: March 2009

This paper describes the measurement of longitudinal residual stresses within specially designed
200x180x25mm groove weld specimens. The purpose of these measurements was to compare the
residual stress field arising from single and multi-pass weld beads laid down within the constraint of
a groove in order to validate finite element simulations of the welding process. Measurements were
made over the cross section at the mid-bead length, utilising the relatively new Contour method and
neutron diffraction. Results from these measurements indicate a larger peak tensile longitudinal
residual stresses within the weld region of the multi-pass weld sample. Good agreement is found
between both techniques.
Grinding-Induced Residual Shear Stresses
Authors: Okolo Brando , Wanner Alexander
Published: March 2009

Pearlitic steel and pure tungsten specimens were ground using a table-type grinding
machine. The thin surface layers affected by the grinding process were characterized using focussed
ion beam milling and microscopy. The strongly graded zone altered due to severe plastic
deformation and recrystallisation was found to be less than 3m thick. The microstructure in that
zone depends on the grinding parameters. Using synchrotron X-ray diffraction, the residual stresses
were measured for penetration depths ranging from 0.25 m to 9 m. Based on the approach by
Dölle and Hauk, the residual shear stresses were separated from the residual normal stresses. In
pearlitic steel, residual shear stresses of opposite sign were observed in the two phases (ferrite and
cementite) and found to be compensating each other, while shear stresses were proved to be absent
in single-phase tungsten. These results underline that residual shear stresses caused by severe plastic
shear deformation exist only as micro-stresses.
Residual Stress Evaluation of Ni Based Weld Metal Using Neutron Diffraction Method
Authors: Okido Shinobu , Suzuki Hiroshi , Saito K.
Published: March 2009

Residual stress generated in Type-316 austenitic stainless steel butt-weld jointed by
Inconel-182 was measured using a neutron diffraction method and compared with values calculated
using FEM analysis. The measured values of Type-316 austenitic stainless steel as base material
agreed well with the calculated ones. The diffraction had high intensity and a sharp profile in the
base metal. However, it was difficult to measure the residual stress at the weld metal due to very
weak diffraction intensities. This phenomenon was caused by the texture in the weld material
generated during the weld procedure. As a result, this texture induced an inaccurate evaluation of
the residual stress. Procedures for residual stress evaluation to solve this textured material problem
are discussed in this paper. As a method for stress evaluation, the measured strains obtained from a
different diffraction plane with strong intensity were modified with the ratio of the individual elastic
constant. The values of residual stress obtained using this method were almost the same as those of
the standard method using Hooke’s law. Also, these residual stress values agreed roughly with those
from the FEM analysis. This evaluation method is effective for measured samples with a strong
texture like Ni-based weld metal.
Residual Stresses and Accuracy of Pipe Preparations by Manufacture Zirconium Tubes for the Nuclear Industry
Authors: Kolmogorov G. , Kuznetsova E. , Filippov V.
Published: March 2009

The production technologies development of thermonuclear reactors is a actual problem
of today. The work researches zirconium goods used in the atomic industry – thin-walled tubes for
the fuel elements shells, thin-walled tubes for the channels of watery and boiling reactors, rods for
lock – plugs of fuel elements; mechanical properties of zirconium and zirconium alloys,
production methods and technologies as well. The power approach is used in the work. The
potential energy of the elastic deformation is regarded as a part of the plastic deformation energy
and a portion of the energy used for residual stresses formation. Using these methods the
distributions of residual stresses are determined by the volume of a product depending on the main
technological parameters of a process and mechanical properties of the material. The results have
shown that hoop stresses take maximum values. The activity of residual stresses can lead to the
elastic deformations and to the departure from the rated dimensions of a product, subsequently,
that is inadmissible for the precision parts. These methods are used to determine the influence of
residual stresses on mechanical properties, precision and operating strength of tube products made
of different zirconium alloys.
Stress Factors and Absolute Residual Stresses in Thin Films Determined by the Combination of Curvature and sin²ψ Methods
Authors: Martinschitz Klaus J. , Eiper Ernst , Keckes Jozef
Published: March 2009

A new method is presented which allows the determination of experimental stress factors
in anisotropic thin films on the basis of static diffraction measurement. The method is based on the
simultaneous characterization of macroscopic stress and elastic strain in thin film using substrate
curvature and sin2ψ methods, respectively. The curvature of monocrystalline substrate with known
mechanical properties is determined using rocking curve measurements on substrate symmetrical
reflections. The experimental stress and strain values are used to calculate stress factors for the
specific film as a function sample tilt angle and reflection measured. The approach represents a
relatively simple recipe to determine residual stress magnitude in thin films on the absolute scale.
The procedure is demonstrated on polycrystalline Cu thin film deposited on Si(100).
Second Order Stresses Distribution in Textured Copper
Authors: Hfaiedh Neila , François Manuel , Saanouni Khemais
Published: March 2009

Internal stresses are an important factor in understanding the work hardening
behaviour of polycrystalline materials. The goal of the present paper is to study the
development of second order stresses in textured copper sheets at large plastic strains, up to
fracture by X-ray diffraction. Second order stresses manifest themselves as peak displacements
and width changes as azimuth and tilt angles are varied. As the acquisition is performed with a
position sensitive detector, a specific correction of intensities is required in order to take into
account texture influence on peak shape and consequently on peak position and width.
Measurement of Residual Stresses in Electrochemically Metallized Coatings on Thin Cross-Cut Ring Substrate
Authors: Lille Harri , Kõo Jakub , Ryabchikov Alexander , Pihl Toomas
Published: March 2009

An experimental method was developed for determination of residual stresses in
electrochemically metallized (brush-plated) coatings by measuring the slit increment of the unclosed
ring strip substrate after deposition process. The substrate is fixed to a mandrel, which makes free
slipping of the edges as well as momentless deformation of the coated substrate possible. The
calculation formula is extended Stoney’s formula which takes into consideration the real shape of
the substrate, and the difference of the elasticity moduli of the coating and the substrate materials.
The difference between the coefficients of thermal expansion of the coating and substrate materials
is also taken into account. Residual stresses are determined for four materials (nickel, zinc, copper,
silver) from six electrolytes.
Intergranular Strain and Phase Transformation in a Cobalt-Based Superalloy
Authors: Benson Michael L. , Stoica A.D. , Liaw Peter K. , Choo Hahn , Saleh T.A. , Wang X.L. , Brown Donald W. , Klarstrom Dwaine L.
Published: March 2009

ULTIMET® alloy, a cobalt-based superalloy with good corrosion and wear resistant
properties, exhibits a deformation-induced phase transformation from the face-centered-cubic
(FCC) phase to the hexagonal-close-packed (HCP) phase. The HCP phase formation during
monotonic tensile loading was investigated using in-situ neutron diffraction. The HCP phase is first
observed at a stress level of 810 MPa, which is well beyond macroscopic yielding. Strain analysis
is performed on the FCC phase diffraction data in order to relate the lattice-strain development with
the evolution of the new HCP phase. A method of calculating the effective macroscopic stress
associated with the measured lattice strains is presented here. The effective stress can then be
compared to the applied macroscopic stress in order to draw conclusions about the load-partitioning
behavior of the material as a new phase develops.
In Situ X-Ray Stress Analysis for the Highly Textured Mg-Base Wrought Alloy AZ31
Authors: Gibmeier Jens , Götting Martin , Zinn Wolfgang , Scholtes Berthold
Published: March 2009

The deformation behaviour of the highly textured Mg-base wrought alloy AZ31 subjected to tensile and compressive elasto-plastic loading was characterized by means of synchrotron radiation. In former publications it was shown that there exists an asymmetry in the deformation behaviour of the investigated alloy, which can be related to the deformation mechanism of the hexagonal structure due to the crystallographic texture relative to the loading direction. A local X-ray stress analysis was carried out on highly textured metal sheets for different {hkil}- planes of the hexagonal crystal structure. The load transfer was investigated within in-situ loading experiments in order to account for suitable XEC´s, thus ensuring accurate stress evaluations. An X-ray imaging method was applied in order to provide bending stress distributions with a high local resolution using synchrotron radiation (beamline G3, Hasylab (DESY)). Stress analyses were carried out on the side face of a bending bar being subjected to elasto-plastic bending up to total strains in the outer layers of approximately 2%. It is distinguished between loading stress distributions measured in in-situ loading experiments as well as residual stress distributions monitored after unloading of elasto-plastically bended bars. Furthermore the loading direction was alternated, in order to investigate the effect of the twin formation as well as the reversibility of the twinning on the results of X-ray stress analysis.
Neutron Strain Scanning of Archaeological Bronzes
Authors: Santisteban Javier R. , Siano S. , Daymond Mark R.
Published: March 2009

We report neutron strain scanning experiments on archaeological bronzes, with the aim
of identifying the original manufacturing techniques used. The specimens studied were a Picenan
necklace from VI BC, and an Etruscan bucket handle from IV BC, exhibited at the Marches
Museum of Archaeology, Ancona, Italy. Time-of-flight neutron diffraction and transmission
experiments were performed at the ENGIN-X instrument, ISIS, UK. For the necklace, characteristic
bending strain profiles and a small degree of preferred orientation indicate that the specimen had
been cold worked. For the handle, broad diffraction peaks and highly distorted Bragg edges -typical
of a columnar grain microstructure- suggested that this specimen was cast and did not undergo
significant thermal or mechanical treatment. The relation between the experimental diffracted and
transmitted time-of-flight spectra, and the microstructure of specimens are discussed.
Design of the Particle Size Composition of an Alumina Powder Matrix for Maximum Flowability and Minimum Water Content
Authors: Silva Abílio P. , Segadães Ana M. , Devezas Tessaleno C.
Published: March 2009

In this work, commercial alumina fine powders were used as raw materials, namely
two tabular alumina fractions (–500 mesh and –230 mesh) and a reactive alumina. Statistical
modelling and the Response Surface Methodology (Statistica, Mixtures Designs and
Triangular Surfaces module) were applied to three-component mixtures and used to calculate
the various property-composition surfaces. To that aim, the various mixtures were prepared,
cast, dried, fired and characterised. The particle size distribution modulus, q, was determined
for all mixtures using the software LISA. The various response surfaces were then combined,
so that the water content in the mixture could be minimised and the matrix flowability
maximised. The properties of the resulting test-bricks (linear shrinkage, mechanical strength,
apparent density and porosity) were also modelled and response surfaces were obtained.
Combined results enabled the definition of an optimised particle size composition range,
which guarantees the presence of a low water flow-bed that enables the aggregate self-flow.
Effect of the Particle Size of the Grog on the Properties and Microstructure of Bricks
Authors: Vieira Carlos Maurício Fontes , Monteiro Sérgio Neves
Published: March 2009

Crushed fired brick waste, known as grog, screened at two different particle size,
840 (20 mesh) and 420 μm (80 mesh), was used in mixtures with clayey body to make typical
red ceramics for bricks. The effect of the grog addition up to 20 wt.% on the properties and
microstructure of bricks fired at 700oC was evaluated. The results indicated that both the
particle size and the amount of grog addition changed the fired properties of the clayey body.
Additions above 5 wt.% of grog, with a coarser particle size, decreased the mechanical
strength of both the dry body and the fired ceramic pieces. By contrast, grog with a finer
particle size may be used up to 10% wt. without deteriorate the properties and corresponding
microstructure of the clayey body.
Brazilian Raw Materials Doped TiO2 Based Electroceramics
Authors: Fontanesi A.P.P. , Cavenaghi J.M. , Sousa Vania Caldas de
Published: March 2009

Dopants such as Ta2O5 play a major role in the formation of barriers at the grain
boundary in TiO2 varistors, increasing their nonlinear coefficient and decreasing their
breakdown electric field. This paper discusses the microstructural and physical properties of
Ta- and Cr-doped TiO2 systems in which imported tantalum oxide was replaced with an
equivalent Brazilian raw material. Preliminary results confirm that this national oxide can be
utilized to obtain electroceramics such as varistors.
Influence of the Type of Dispersant on the Properties of Casting Slips of Porcelains with Soda-Lime Glass
Authors: Bragança S.R. , Camaratta R. , Taborda A.C. , Bergmann C.P.
Published: March 2009

The use of glass residues for the reduction of firing temperature of ceramic materials products
has become an attractive alternative. For pressed or extruded products, such as tiles and
bricks, the use of glass is sufficiently simple, since only milling and mixing to the industrial
mass batch in partial substitution of conventional fluxes are necessary. However, in slip
casting products, such as china and porcelains, the glass presence destabilizes the casting slip.
This is the motivation of this work. Different types of dispersants and their influence on the
properties of slips containing glass waste were evaluated. The experimental results showed
that the use of conventional dispersant (sodium silicate) is not adequate. The stabilization of
slips was possible only with organic dispersants. Therefore, the factors that determine the
success or failure of dispersants were also analyzed.