Non-destructive X-ray Diffraction Research Articles

Influence of cement and water content on the multifaceted capabilities of a self-sensing cement-based geocomposite: a comprehensive analysis

This study investigates the synergistic effects of cement, water, and hybrid carbon nanotubes/graphene nanoplatelets (CNT/GNP) concentrations on the mechanical, microstructural, durability, and piezoresistive properties of self-sensing cementitious geocomposites. Varied concentrations of cement (8% to 18%), water (8% to 16%), and CNT/GNP (0.1% to 0.34%, 1:1) were incorporated into cementitious stabilized sand (CSS). Mechanical characterization involved compression and flexural tests, while microstructural analysis utilized dry density, apparent porosity, water absorption, and non-destructive ultrasonic testing, alongside TGA, SEM, EDS, and x-ray diffraction analyses. The durability of the composite was also assessed against 180 Freeze-thaw cycles. Moreover, the piezoresistive behavior of the nano-reinforced CSS was analyzed during cyclic flexural and compressive loading using the four-probe method. The optimal carbon nanomaterials (CNM) content was found to depend on the water and cement ratios. Generally, elevating the water content led to a rise in the CNM optimal concentration, primarily attributed to improved dispersion and adequate water for the cement hydration process. The maximum increments in flexural and compressive strengths, compared to plain CSS, were significant, reaching up to approximately 30% for flexural strength and 41% for compressive strength, for the specimen containing 18% cement, 12% water, and 0.17% CNM. This improvement was attributed to the nanoparticles’ pore-filling function, acceleration of hydration, regulation of free water, and facilitation of crack-bridging mechanisms in the geocomposite. Further decreases in cement and water content adversely impacted the piezoresistive performance of the composite. Notably, specimens containing 8% cement (across all water content variations) and 10% cement (with 8% and 12% water content) showed a lack of piezoresistive responses. In contrast, specimens containing 14% and 18% cement displayed substantial sensitivity, evidenced by elevated gauge factors, under loading conditions.

Residual Stress Mapping in Heat-Assisted Additive Manufacturing of IN 718: An X-Ray Diffraction Study

Laser powder bed fusion (LPBF) is a type of additive manufacturing (AM) technique characterized by multiple localized thermal processes that result in rapid heating and cooling. The thermal variations observed in the LPBF process can generate residual stress (RS) inside the fabricated part, impacting the surface integrity and geometric tolerances of the manufactured components. To reduce thermal variation during manufacturing, heat-assisted AM was employed, thereby minimizing RS and any thermal distortion that could occur during the fabrication of materials. The present research utilizes non-destructive x-ray diffraction to analyze the influence of an in-situ heated building plate and processing parameters on the RS distribution in Inconel 718 (IN718) fabricated by LPBF. This study examines the impact of two scanning procedures and three laser power levels and offers critical insights into both measurement techniques and RS characterization. By understanding the effect of the processing parameters on RS, we aim to enhance the quality of manufactured parts through process optimization. Post-processing heat treatment consistently reduced RS in all samples, regardless of laser power levels or scanning strategies. Combining a chess scanning strategy with 270 W laser power resulted in the most significant RS reduction in IN718.

The influence of hatch distance on the surface roughness, microhardness, residual stress, and density of inconel 625 specimens in the laser powder bed fusion process

ABSTRACT The main goal of the laser powder bed fusion process is to produce high-quality parts with the required mechanical properties. Achieving this requires the proper selection of the key process parameters including laser power, scanning speed, layer thickness and hatch distance. In the present article, the effect of hatch distance parameter on the surface integrity issues i.e. surface roughness, residual stress, microhardness, and also density of Inconel 625 specimens has been studied using experimental approach. By using the non-destructive X-ray diffraction technique, residual stresses were measured in the different portion of the samples whose cross section changes. According to the results, as the hatch distance increases the microhardness decreases. The hatch distance has inverse effect on the residual stresses which its effect is less at the lower sections. It can be stated generally that the hatch distance increment reduces the microhardness, residual stress, and surface roughness but increases the specimen’s density.

Non-destructive X-ray diffraction surface integrity inspection of an aeroengine component

Industry standard assessment of machined surface integrity typically requires a form of destructive testing to capture microstructural features such as white layers or distorted layers. The X-ray diffraction surface integrity inspection method (XRD-SIIM) offers a non-destructive alternative for the detection and sizing of fatigue-limiting microstructural features, without the sacrifice or alteration of a component which is required for cross-sectional microscopy. In this study XRD-SIIM was used to measure the surface integrity across a nickel-based superalloy gas turbine disc segment. XRD-SIIM microstructural feature detection and sizing models were trained and validated from a set of surfaces generated in a turning trial with a newly developed calibration procedure allowing these models to be adjusted for different instrument setups to facilitate measurement of the turbine disc segment. The non-destructive test was then able to show comparable inspection results to industry standard microscopy of microstructural features when inspecting the representative component, with over 90% of the outside surface of the component accessible by the diffractometer, and the internal surfaces accessible with appropriate hardware. Surface curvature only became a limiting factor for inspection of geometrical features with a small radius of curvature such as seal fins and the corner radii on fir tree sections.

A Review of Non-Destructive Evaluation (NDE) Techniques for Residual Stress Profiling of Metallic Components in Aircraft Engines

Residual stresses are one of the main factors determining the failure of aircraft engine materials. It is not possible to reliably and accurately predict the remaining service life of aircraft engine components without properly accounting for the presence of residual stresses. The absolute level and spatial distribution of the residual stress is uncertain in aircraft engines because the residual stress profile is highly susceptible to variations in the manufacturing process. In addition, residual stresses keep evolving under complex thermal-mechanical loadings. Non-destructive techniques are desired by the aerospace industries for the regular monitoring of subsurface residual stress profile in aircraft engine components. The insufficient penetrating capability of the only currently available non-destructive residual stress assessment technique X-ray diffraction has prompted an active search for alternative non-destructive techniques. This paper provides an overview of the principle, practical applications, advantages, and limitations of four categories of nondestructive (diffraction, ultrasonic, and electromagnetic) techniques for residual stress profiling of metallic components in aircraft engines.

Phase transformation, morphology, DC electrical resistivity and dielectric properties investigations of properties of manganese doped barium titanate nanoparticles

In this work, manganese (Mn) doped barium titanate BaTi1-xMnxO3 nanoparticles with varying composition of Mn (x = 0.0, 0.10 and 0.20) were prepared by using sol–gel self-ignition wet chemical route. The influence of Mn doping on crystal structure, infra-red, morphology, DC electrical resistivity and frequency dependent dielectric studies was systematically investigated. To know the crystalline nature and purity of the prepared samples, a non-destructive X-ray diffraction (XRD) tool was used. The analysis of XRD results revealed that pure BaTiO3 and BaTi1-xMnxO3 with x = 0.1, samples show tetragonal structure and for higher Mn content (x = 0.20) shows the hexagonal structure. The values of interplanar spacing, Miller indices, etc. were used to determine the unit cell parameters, X-ray density and unit cell volume. The highest intensity peak (110) observed in XRD pattern was considered to determine the crystalline size and which is found to be in the range of 3 to 8 nm. Scanning electron microscopy (SEM) technique was employed to study the surface morphology. SEM analysis confirm the dense nature of the grains with hexagonal shape for x = 0.2. EDX results confirm the presence of Ba, Ti, Mn and O elements as per the stoichiometric proportion. The functional groups and chemical bonds of Mn doped BaTiO3 were obtained by Fourier transform infrared spectroscopy (FTIR). The temperature dependant DC electrical resistivity studies were performed by standard two probe technique. The conductivity plot exhibits negative temperature coefficient (NTC). The activation energy and resistivity both decreased with Mn doping. The dielectric properties such as dielectric constant (ε′), dielectric loss (ε″) and dielectric loss tangent (tan δ) were studied by means of LCR-Q meter. The variation of these parameters as a function of frequency shows the exponential decrease. The dielectric constant and dielectric loss reduces, whereas dielectric loss tangent increase on Mn doping. The ac conductivity increases with frequency.

In-line Raman spectroscopy for gate-all-around nanosheet device manufacturing

In-line Raman spectroscopy for compositional and strain metrology throughout front-end-of-line (FEOL) manufacturing of next-generation gate-all-around nanosheet field-effect transistors is presented. Thin and alternating layers of fully strained pseudomorphic Si(1 − x)Gex and Si were grown epitaxially on a Si substrate and subsequently patterned. Intentional strain variations were introduced by changing the Ge content (x = 0.25, 0.35, 0.50). Polarization-dependent in-line Raman spectroscopy was employed to characterize and quantify the strain evolution of Si and Si(1 − x)Gex nanosheets throughout FEOL processing by focusing on the analysis of Si-Si and Si-Ge optical phonon modes. To evaluate the accuracy of the Raman metrology results, strain reference data were acquired by non-destructive high-resolution x-ray diffraction and from destructive lattice deformation maps using precession electron diffraction. It was found that the germanium-alloy composition as well as Si and Si(1 − x)Gex strain obtained by Raman spectroscopy are in very good agreement with reference metrology and follow trends of previously published simulations.

Spatial correlation of embedded nanowires probed by X-ray off-Bragg scattering of the host matrix

It is shown that information on the spatial correlation of nano-objects embedded in a crystalline matrix can be retrieved by analysing the X-ray scattering around the Bragg reflections of the host matrix. Data are reported for vertically aligned Ni and CoNi alloy nanowires (NWs) in an SrTiO3 matrix. When the Bragg condition is fulfilled for the matrix and not for the NWs, the latter can be approximated by voids, and the scattering around the matrix reflections contains information on the self-correlation of the NWs (i.e. on their diameter d) and on the correlation between NWs (interdistance D). Nondestructive synchrotron X-ray diffraction data provide information on these values averaged over large areas, complementing local transmission electron microscopy observations. The measurements show that off-Bragg scattering around the matrix reflections can be exploited to study the spatial correlation and morphology of embedded nano-objects, independently of their crystallinity or strain or the presence of defects.

Shine on you crazy diamond: Symbolism and social use of fluorite ornaments in Iberia’s late prehistory

Fluorite ornaments have been recorded in different sites of Europe since Upper Paleolithic. Due to its visual appearance and physical properties, some translucent or transparent mineralogies like fluorite were searched for or casually acquired by late prehistory’s human communities. After intensive research on archaeological contexts from the Iberian Peninsula with personal ornaments from 4th to 2nd millennia BCE, we have recently identified and characterized for the first time an important number of fluorite ornaments, confronting a previous background where little attention was paid. Our work has been carried out in different archaeological collections and museums from the whole Iberian Peninsula by non-destructive techniques (Raman spectroscopy, portable X-ray fluorescence (p-XRF) and X-ray Diffraction (XRD), that revealed the nature of fluorite ornaments and points to its consideration as scarce and highly symbolic items during late prehistory. A total of 36 fluorite beads from 23 sites are here recorded and studied, many of them inedits or wrong catalogued as other mineralogies. These adornments could have important roles in trade and use among the communities of Iberia from the 4th millennium BCE onwards, because of their scarcity and its recurrent association with important funerary complex and exotic materials. Fluorite ornaments could have been significant and special symbols in the development of new and exclusive raw materials in the context of increasing social complexity and inequality.

Experimental validation of residual stress thermomechanical simulation in as-quenched superalloy discs by using diffraction and incremental hole-drilling methods

Mechanical properties of commercial Ni-based superalloys at elevated temperature rely strongly on the cooling rate during solution heat treatment. Quenching-induced residual stress can be crucial to machining accuracy and fatigue strength of industrial superalloy components.In this study, an existing finite-element-based methodology is improved by inverse heat transfer calculation and phase transformation latent heat input, with a maximum temperature deviation of ∼44℃. The simulated thermal stress and strain rate evolution demonstrate the origin of the quenching stress field. Robust non-destructive methods, i.e., neutron diffraction and X-ray diffraction, are employed to validate the simulated surface and internal residual stresses in both air-cooled and water-quenched discs. The simulated in-depth normal residual stress profiles are proven to be consistent with the results of non-destructive measurement, with a maximum average deviation of ∼34 MPa. After a rapid quenching process, the near-surface stress gradient measured by incremental hole-drilling method at a depth of 0.45 mm is ∼150 % lower than simulation result.

Annealing of focused ion beam damage in gold microcrystals: an in situ Bragg coherent X-ray diffraction imaging study.

Focused ion beam (FIB) techniques are commonly used to machine, analyse and image materials at the micro- and nanoscale. However, FIB modifies the integrity of the sample by creating defects that cause lattice distortions. Methods have been developed to reduce FIB-induced strain; however, these protocols need to be evaluated for their effectiveness. Here, non-destructive Bragg coherent X-ray diffraction imaging is used to study the in situ annealing of FIB-milled gold microcrystals. Two non-collinear reflections are simultaneously measured for two different crystals during a single annealing cycle, demonstrating the ability to reliably track the location of multiple Bragg peaks during thermal annealing. The thermal lattice expansion of each crystal is usedtocalculate the local temperature. This is compared with thermocouple readings, which are shown to be substantially affected by thermal resistance. To evaluate the annealing process, each reflection is analysed by considering facet area evolution, cross-correlation maps of the displacement field and binarized morphology, and average strain plots. The crystal's strain and morphology evolve with increasing temperature, which is likely to be caused by the diffusion of gallium in gold below ∼280°C and the self-diffusion of gold above ∼280°C. The majority of FIB-induced strains are removed by 380-410°C, depending onwhich reflection is being considered. These observations highlight the importance of measuring multiple reflections to unambiguously interpret material behaviour.

Effect of zinc substitution on U-type barium hexaferrite-epoxy composites as designed for microwave absorbing applications

In the current study, U-type barium hexaferrite (BHF) poly-crystalline powder with chemical formula Ba4Co2−xZnxFe36O60 (0.5 ≤ x ≤ 1.5 in step of 0.5) were successfully synthesized by solid state reaction route at the sintering temperature of 1400 °C in air medium. The effect of Zn+2 substitutions on the crystalline structural and magnetic properties of BHF powders were examined through nondestructive X-ray diffraction (XRD) technique and vibrating sample magnetometer (VSM) respectively. Upon increasing Zn+2 content the lattice parameters a and c decreases which is leading to the X-ray density up to a small degree, due to a smaller ionic size of Zn+2 as compared to Co+2 ions and saturation magnetization (Ms) from 56.08 emu/g for the zinc substituted sample down to 54.79 emu/g was observed. The transmission electron microscope (TEM) depicted that the particle size reached a minimum at x = 0.5 and then grown with x = 1.5 zinc content, getting a value of 103.06 nm with hexagonal phase and finer grains having the size range of ~0.51–1.0 µm thick and 5 µm long which is confirmed by field emission scanning electron microscopy (FESEM). A series of BHF-epoxy composites has been further transformed into toroidal shaped composites with fix volume percentage (54.3 vol%) of BHF powder in epoxy matrix. Electromagnetic properties; complex permittivity (εr = ε′ − jε″) and complex permeability (μr = μ′ − jμ″) of the prepared composites were computed through coaxial measurement techniques by using an Agilent E8364B vector network analyzer. Minimum return loss (RLmin) was observed as −32.98 dB (maximum absorption " 99.92) for matching frequency 10.3 GHz of the absorber with thickness of 3.1 mm and the bandwidth achieved was 7.38 GHz. Absorption values for prepared composites have potential use as excellent microwave absorbers over the frequency band C-band, X-band and Ku-band.

Metamaterials Based on Polyvinyl Alcohol with Metal or Metal Oxide Particles: Synthesis and Study by Nondestructive Physical Methods

Methods for the synthesis of polymer hydrogel–metal metamaterials based on polyvinyl alcohol and reduced Cu, Ag, Co, and Fe (or magnetite Fe3O4) particles, including the stage of chemical or thermal reduction or chemical precipitation were proposed. The effect of the synthesis conditions on the size of metal or oxide particles and the regularity of particle distribution in the polymer was studied. The samples of composite materials synthesized under different conditions were characterized by nondestructive X-ray fluorescence and X-ray diffraction methods. An XRD study revealed that after the thermal reduction of Cu, Co, and Fe, the composite contained a significant amount of metal oxides. The optimum conditions for the synthesis of polyvinyl alcohol–magnetite metamaterials were found.

Residual stress in struck and cast coins

It has been shown that the metal on struck coin surfaces demonstrates residual elastic compression while the metal on cast coin surfaces demonstrates no stress at all or, sometimes, elastic tension. Non-destructive X-ray diffraction (XRD) (the so-called 'sin 2 Ψ method') is applied in this work for residual elastic stress analysis. It is quite an effective tool in the authentication of coins by establishing the production method of such objects (struck or cast).

Nondestructive evaluation of 3D microstructure evolution in strontium titanate

Nondestructive X-ray diffraction contrast tomography imaging was used to characterize the microstructure evolution in a polycrystalline bulk strontium titanate specimen. Simultaneous acquisition of diffraction and absorption information allows for the reconstruction of shape and orientation of more than 800 grains in the specimen as well as porosity. Three-dimensional microstructure reconstructions of two coarsening states of the same specimen are presented alongside a detailed exploration of the crystallographic, topological and morphological characteristics of the evolving microstructure. The overall analysis of the 3D structure shows a clear signature of the grain boundary anisotropy, which can be correlated to surface energy anisotropy: the grain boundary plane distribution function shows an excess of 〈100〉-oriented interfaces with respect to a random structure. The results are discussed in the context of interface property anisotropy effects.

Numerical calculation and experimental measurement of temperatures and welding residual stresses in a thick-walled T-joint structure

In this investigation, a T-joint numerical welding simulation of thick steel plates is performed to estimate transient temperature distributions, residual stress field and model deflections. A sequential simulation method is applied in the numerical simulation, where the thermal analysis is done by using the EBD technique to simulate the weld wire melting and metal filler addition while the mechanical analysis is performed in one step without EBD to shorten the calculation time. Thermocouples, non-destructive X-ray diffraction and semi-destructive hole-drilling methods are used to measure the temperature and residual stress distributions. In the thermal analysis, a simplified heat flux is used which causes a relatively large temperature discrepancy in the weld pool area between the numerical and experimental results. The calculated temperature histories outside the weld pool and its vicinity correlate very well with the experimental measurements with an acceptable discrepancy of approximately 4%. The residual stresses are firstly measured on the model surface without electropolishing and then two times after that, at depths of 0.005 and 0.015 mm. The results of residual stress obtained by numerical modelling and measurement with X-ray agree better when the electropolishing removing layer is set to 0.015 mm, due to a significantly smaller effect of surface conditions that originate from steel plate production.

Possibility about Application and Interpretation of Surface Nondestructive X-ray Diffraction Method for Cultural Heritage Samples by Material

Possibility about Application and Interpretation of Surface Nondestructive X-ray Diffraction Method for Cultural Heritage Samples by Material

Synergic effect of Zinc (Zn) precursors on the microstructural, optical and electrical properties of Zinc oxide thin films for solar cell applications

Zinc oxide (ZnO) nanoparticles, with their inimitable characteristics such as easy synthesis, high selectivity and enhanced cytotoxicity are becoming progressively important candidate in modern applications. In this study, we have systematically investigated the effect of fabrication conditions on the morphological, structural, optical and electrical properties of zinc oxide (ZnO) thin films. It was observed that the change in Zn-precursor leads to the growth of grains structure at the surface of ZnO thin films. Broadly mentioned, two different regions of growth were observed with the change in the Zn precursor medium. The presence of ZnO hexagonal structure wurtzite was confirmed with the help of non-destructive X-ray Diffraction (XRD) analysis. Scanning Electron Microscopy (SEM) showed that the islands of nano-grains started to nucleate into highly stressed, uniform and roughly compact morphology of the ZnO grains structures of the crack-free thin films. The as-fabricated ZnO thin films comprised of micro and nanoparticles grains structures. The electrical properties measurement revealed the decrease in the average resistivity with the change in Zn-precursor solution of the as-fabricated ZnO thin films. The UV–Vis. Spectroscopy showed the optical absorption spectra of the ZnO thin films have maximum transmittance in the visible region i.e. 80 %. Such kind of films characteristics are very important for solar spectra. It was observed that the change in Zn precursor solution has impact on the transmittance properties of the ZnO thin films. This study highlights an environment friendly, low cost and facile roots for the fabrication of ZnO thin films for probable use in solar cells applications.

Investigations of surface micro topologies and crystalline behaviour of hybrid wood composites

The aim of present work is to evaluate the surface micro topologies and crystalline behaviour of hybrid wood composites which is prepared by hand lay-up method using pinus and shorea robusta wood particulates as reinforcement materials and epoxy resin as a matrix material. The surface micro topologies and crystalline behaviour of the prepared hybrid wood composites are examined by optical non-destructive test and x-ray diffraction respectively. The surface micro-topological parameters such as average roughness (), maximum peak-to-valley height () and mean peak-to-valley height () are recorded by the optical profilometer. The crystallinity of hybrid composite is measured in diffractograms recorded by the x-ray Diffractometer. The surface roughness of shorea robusta wood particulates composite decreases by 31.7% with the addition of equal amount of pinus wood particulates; shows a positive effect of hybridization of these two wood particulates. Moreover, a positive effect of hybridization is also observed in crystalline behaviour as hybrid wood composites exhibited the better crystallinity as compared to single wood composites.

Effect of Residual Stresses of GTA Welding for Dissimilar Materials

The purpose of the present work is to understand the evolution of residual stresses in weldments. The study made to weld the multipass dissimilar of Nickel-based superalloy Inconel 625 and stainless steel 316L using Continuous Current Gas Tungsten Arc Welding (CCGTAW) and Pulsed Current Gas Tungsten Arc Welding (PCGTAW) process employing ERNiCrMo-3 and ERNiCr-3 fillers. The L4 orthogonal array was used in the present experimentation process. Analysis of Variance (ANOVA) is applied for the optimization and to identify the critical parameters. In welding process, the size of the lattice size will be stressed due to welding parameters; the lattice dimension is measured by non-destructive technique X-Ray diffraction to investigate residual stress in the weldment in the lateral surface of the plate. X-Ray Radiography test has evaluated the quality of welds. The results show that root gap is a critical parameter and filler wire and weld processes are not critical.