X-ray diffraction grazing-incidence methods applied for gradient-free residual stress profile measurements in electrodeposited Ni coatings

2015 ◽  
Vol 48 (1) ◽  
pp. 71-78 ◽  
Author(s):  
Bogusz Kania ◽  
Paulina Indyka ◽  
Leszek Tarkowski ◽  
Ewa Beltowska-Lehman

The present work investigates the possibility of bias introduced in grazing-incidence-angle X-ray diffraction techniques applied to residual stress measurements. In these studies, monotextured nanocrystalline nickel coatings obtained by electrodeposition were examined as the model reference samples. Selected Ni coatings exhibited well developed and simple gradient-free residual stress states that were visible using conventional sin2ψ measurements with varying X-ray penetration depths. These results were verified against the stress state picture obtained by two variants of grazing-incidence X-ray methods: multi-reflection (differenthkl) and constant angle of incidence (singlehkl). The outcome of both grazing techniques consistently excluded stress gradients in the samples, which agreed with conventional sin2ψ measurement results. However, only the results of the constant angle of incidence technique agreed with those obtained by the sin2ψ method in terms of calculated residual stress level, suggesting this approach could be applied in further studies of graded material coatings. All analysed coatings yielded uniformly distributed tensile residual stress related to gradual structure development in electrodeposited Ni coatings studied by electron microscopy techniques.

2010 ◽  
Vol 638-642 ◽  
pp. 2464-2469 ◽  
Author(s):  
Cristy Leonor Azanza Ricardo ◽  
G. Degan ◽  
M. Bandini ◽  
Paolo Scardi

The residual stress profile in a shot-peened Al alloy component was studied by a recently proposed method based on the known procedure of progressive thinning and X-ray Diffraction measurements. The effect the cyclic stress on the fatigue life was studied in detail, showing the correlation between nominal load and residual stress relaxation. Besides showing the expected decrease of compressive stress with the load and number of cycles, the present work highlights the importance of changes in the through-the-thickness residual stress distribution.


2008 ◽  
Vol 571-572 ◽  
pp. 277-282 ◽  
Author(s):  
Xu Song ◽  
Solène Chardonnet ◽  
Giancarlo Savini ◽  
Shu Yan Zhang ◽  
Willem J.J. Vorster ◽  
...  

The aim of the study presented here was to evaluate the residual stresses present in a bar of aluminium alloy 2124-T1 matrix composite (MMC) reinforced with 25vol% particulate silicon carbide (SiCp) using X-ray diffraction and 3D profilometry (curvature measurement using Mitutoyo/Renishaw coordinate measurement machine) and comparing these results with numerical models of residual strain and stress profiles obtained by a simple inelastic bending model and Finite Element Analysis (FEA). The residual strain distribution was introduced into the test piece by plastic deformation in the 4-point bending configuration. At the first stage of this study the elasticplastic behaviour of the MMC was characterized under static and cyclic loading to obtain the material parameters, hardening proprieties and cyclic hysteresis loops. Subsequently, synchrotron Xray diffraction and CMM curvature measurements were performed to deduce the residual stress profile in the central section of the bar. The experimental data obtained from these measurements were used in the inelastic bending and FEA simulations. The specimens were then subjected to incremental slitting using EDM (electric discharge machining) with continuous back and front face strain gauge monitoring. The X-ray diffraction and incremental slitting results were then analysed using direct and inverse eigenstrain methods. Residual stresses plots obtained by different methods show good agreement with each other.


2014 ◽  
Vol 996 ◽  
pp. 769-774
Author(s):  
Diego Cecchin ◽  
Evgeny Kobza ◽  
Marco Cazzolli ◽  
Cristy Leonor Azanza Ricardo ◽  
Mirco D'Incau ◽  
...  

Tool steel (X155CrVMo121KU in the following UK15) samples were analyzed to determine the in-depth residual stress profile and to study modifications in the microstructure, induced by a shot-peening treatment. The influence of different tempering temperatures was studied. Residual stress and dislocation density profiles were measured using standard laboratory X-ray diffraction (XRD) residual stress analysis with progressive chemical layer removal. Dislocation density profiles where obtained using a Whole Powder Pattern Modeling (WPPM) procedure.


2016 ◽  
Vol 49 (3) ◽  
pp. 961-967 ◽  
Author(s):  
D. Grigoriev ◽  
S. Lazarev ◽  
P. Schroth ◽  
A.A. Minkevich ◽  
M. Köhl ◽  
...  

A procedure for obtaining three-dimensionally resolved reciprocal-space maps in a skew X-ray diffraction geometry is described. The geometry allows tuning of the information depth in the range from tens of micrometres for symmetric skew diffraction down to tens of nanometres for strongly asymmetric skew geometries, where the angle of incidence is below the critical angle of total external reflection. The diffraction data are processed using a rotation matrix formalism. The whole three-dimensional reciprocal-space map can be measured by performing a single azimuthal rotation of the sample and using a two-dimensional detector, while keeping the angle of incidence and the X-ray information depth fixed (FIXD method). Having a high surface sensitivity under grazing-incidence conditions, the FIXD method can be applied to a large variety of Bragg reflections, particularly polar ones, which provide information on strain and chemical composition separately. In contrast with conventional grazing-incidence diffraction, the FIXD approach reveals, in addition to the lateral (in-plane) components, the vertical (out-of-plane) component of the strain field, and therefore allows the separation of the scattering contributions of strained epitaxial nanostructures by their vertical misfit. The potential of FIXD is demonstrated by resolving the diffraction signal from a single layer of InGaN quantum dots grown on a GaN buffer layer. The FIXD approach is suited to the study of free-standing and covered near-surface nano-objects, as well as vertically extended multilayer structures.


2020 ◽  
Vol 60 (4) ◽  
pp. 475-480
Author(s):  
V. A. N. Righetti ◽  
T. M. B. Campos ◽  
L. B. Robatto ◽  
R. R. Rego ◽  
G. P. Thim

2006 ◽  
Vol 514-516 ◽  
pp. 1618-1622 ◽  
Author(s):  
Maria José Marques ◽  
J.C.P. Pina ◽  
A. Morão Dias

The conventional Bragg diffraction geometry, normally used to characterize the residual surface stress state, it is not suitable to evaluate surface treated materials and thin films. The X-ray path lengths through a surface layer or thin film are too short to produce adequate diffraction intensities in relation to the bulk or the substrate. Another limitation of the conventional technique appears when a residual stress gradient is present in the irradiated surface. The technique only enables the evaluation of the mean value of this gradient. In these cases, a recently proposed Pseudo-Grazing Incident X-ray Diffraction method would be better applicable. In this study, the Pseudo-Grazing Incidence X-ray Diffraction is applied to characterize the residual stress depth profiles of several AISI 4140 samples, which were prepared, by mechanical polishing and grinding, in order to present different surface roughness parameters, Ra. The experimental results lead to the conclusion that the surface roughness limits the application of the Pseudo-Grazing Incidence methodology to a minimum X-ray incident angle. This angle is the one that enables a mean X-ray penetration depth with the same order of magnitude of the sample surface roughness parameter, Ra.


1998 ◽  
Vol 5 (3) ◽  
pp. 488-490 ◽  
Author(s):  
Yasuo Takagi ◽  
Masao Kimura

A new and more `generalized' grazing-incidence-angle X-ray diffraction (G-GIXD) method which enables simultaneous measurements both of in- and out-of-plane diffraction images from surface and interface structures has been developed. While the method uses grazing-incidence-angle X-rays like synchrotron radiation as an incident beam in the same manner as in `traditional' GIXD, two-dimensional (area) detectors like image plates and a spherical-type goniometer are used as the data-collection system. In this way, diffraction images both in the Seemann–Bohlin (out-of-plane) and GIXD geometry (in-plane) can be measured simultaneously without scanning the detectors. The method can be applied not only to the analysis of the in-plane crystal structure of epitaxically grown thin films, but also to more general research topics like the structural analysis of polycrystalline mixed phases of thin surface and interface layers.


2013 ◽  
Vol 768-769 ◽  
pp. 264-271 ◽  
Author(s):  
Ursula Selvadurai ◽  
W. Tillmann ◽  
Gottfried Fischer ◽  
Tobias Sprute

In this research work, Ti/TiAlN multilayers of various designs were deposited on substrates pretreated by nitriding and etching procedures. The influence of the multilayer design on residual stress depth profiles was systematically analyzed for multilayers with different Titanium interlayer thicknesses. The depth dependency of stress was measured by a modified sin2ψ method, using various defined gracing incident angles and measuring angles that ensure constant penetration depths. The residual stresses were investigated by synchrotron X-ray diffraction (SXRD) at the HASYLAB at DESY in Hamburg, Germany. SXRD allows a phase specific stress evaluation of the ceramic and metallic layers of the multilayer systems and the adjacent substrate region. This investigation reveals an influence of the Ti layer thickness on the values and the slope of the residual stress profile in ceramic TiAlN layers.


Author(s):  
Cameron Lonsdale ◽  
John Oliver

Recent work using x-ray diffraction techniques has shown that the axial residual stress pattern within the railroad wheel rim is significantly different for as-manufactured AAR Class C wheels vs. AAR Class C wheels that have failed due to a vertical split rim (VSR), and non-failed AAR Class C wheels that have been operating in service. VSRs almost always begin at areas of tread damage, resulting from shelling or spalling, and cracking propagates into the rim section under load. At the locations tested, the as-manufactured wheels have a relatively “flat” axial residual stress profile, compressive but near neutral, caused by the rim quenching operation, while wheels that have been in service have a layer of high axial compressive stress at the tread surface, and a balancing zone of axial tensile stress underneath. The magnitude and direction of this tensile stress is consistent with the crack propagation of a VSR failure. When cracks from the tread surface propagate into this sub-surface axial tensile zone, a VSR can occur under sufficient additional service loading, such as loads caused by in-service wheel/rail impacts from tread damage. Further, softer Class U wheels, removed from service and tested, were found to have a balancing axial tensile stress layer that is deeper below the tread surface than that found in used Class C wheels. This paper describes further efforts to characterize the axial residual stress present in failed VSR and used Class C wheels. Axial residual stress results are obtained near the initiation point of several VSR wheels using x-ray diffraction. Sub-surface axial residual stress patterns are also determined at points of high out-of-roundness for a group of wheels that were tested for TIR (total indicated runout) on the tread surface. Residual stress data and a photo are presented for a wheel rim slice containing a second VSR crack. Additionally, wheel rim ultrasonic testing data, collected by the wheel manufacturer when the wheels were new, are discussed for wheels that have failed due to VSRs and these data are compared to ultrasonic data for non-VSR wheels. Chemistry data are also compared. These data show that the driving force for VSRs is axial residual tensile stress, not a material cleanliness issue.


Sign in / Sign up

Export Citation Format

Share Document