bluuebunny/crossref_metadata_2025 huggingface dataset:
A study on the wave propagation on weld joints by the use of feature-guided wave mixing
Authors:   Changwon National University, Lee Jaesun ,   Changwon National University, Mohammed Aslam
Published: July 2023

The concentration of the wave energy around certain features such as bends, stiffeners, and welds in plate-like structures has been identified as feature-guided waves (FGW). In practice, these features can be useful for assessing defects in or near them. The propagation characteristics of FGW propagating along a feature such as a welded joint have been extensively studied. However, most of them are based on the linear acoustic response of materials that generally results in the amplitude and phase variations of the input signal. Compared to linear methods, nonlinear ultrasonic techniques have shown to be effective in characterizing the microstructural changes in engineering materials. In this paper, a wave mixing method is employed to investigate the nonlinear acoustic response of FGWs propagating in a welded joint. The dispersion characteristics of weldguided modes are first revealed via the eigenfrequency analysis of an unbounded welded plate by using the finite element method. The nonlinear response of FWGs is studied through 3D finite element (FE) simulations. A pair of a weld-guided modes of different frequencies are identified and allowed to mix within the welded joint to generate second-order harmonic waves. The current study reveals that the mixing of FGWs could be effectively used for the evaluation of material nonlinearity in welded joints.
Visualization of wave modes generated by electromagnetic acoustic transducers with the photoelastic imager
Authors:   Salzgitter Mannesmann Forschung GmbH, Kaack Michael ,   Salzgitter Mannesmann Forschung GmbH, Hillen Leonie ,   Salzgitter Mannesmann Forschung GmbH, Schmitte Till ,   Salzgitter Mannesmann Forschung GmbH, Orth Thomas
Published: July 2023

Typical electromagnetic acoustic transducers (EMATs) applied in steel industry are designed for the generation of transversal waves. The probe type investigated here is designed for perpendicular incidence but exhibits several unwanted signals in a typical A-scan that are difficult to identify and to assign to possible wave modes. In this study a photoelastic imager setup is used to allow ultrasonic waves to be generated and observed in a glass sample. Image enhancement techniques were applied to improve the signal-to-noise ratio so that even weak wave modes become visible. By generating waves in conductive but non-magnetic, non-conductive but magnetic and conductive and magnetic materials the contributions of Lorenz-, magnetic and magnetostrictive forces could be separated. It is found that transversal waves have their origin in Lorenz- and magnetostrictive forces, while the largest contribution to longitudinal waves comes from magnetic forces leading to an unfavourable propagation direction. Several unexpected wave modes were detected that most probably origin from deviations of the realization from ideal configurations. Understanding these effects will help to improve the EMAT probe design for future applications.
X-ray Computed Tomography Inspection of Novel Ceramic Matrix Composites
Authors:   diondo GmbH, Brierley Nick ,   diondo GmbH, Chrzan Karin ,   diondo GmbH, Günnewig Olaf ,   Deutsches Zentrum für Luft- und Raumfahrt (DLR), Kessel Fiona ,   PFW Aerospace GmbH, Backe Daniel
Published: July 2023

Novel Ceramic Matrix Composites (CMCs) offer the promise of more highly performing structures, especially in aerospace applications, due to their excellent mechanical properties at elevated temperatures with respect to their density and their corrosion resistance. However, the development of such materials requires careful characterisation, and any deployment on an aircraft necessitates an appropriate nondestructive testing capability. This work sought to deploy and refine the method of Xray Computed Tomography (CT) in aid of the development of a novel CMC and subsequent deployment in a flying component. The target application was part of the exhaust system of a civil aircraft’s auxiliary power unit. The work included material characterisation at coupon-level, as well as technique development with a view towards the target application. For the former, high-resolution scans were performed in a range of configurations, including during tensile testing, to provide an understanding of microstructure and failure behaviour. For the latter, novel system configurations were explored to try to deal with the challenge of a large, thin-walled structure. Additionally, alternative or complimentary non-X-ray testing methods were trialled, notably including terahertz (THz) imaging. The material characterisation demonstrated the potential for the novel material to meet the requirements of the application. The terahertz imaging in a through transmission configuration was the most capable of the non-radiographic methods tested, providing an image that correlated very well with the reference CT scan, whilst the system development efforts yielded a configuration optimised for this class of 3D X-ray imaging applications.
Merged Mode TFM with Mode Conversion Artifact Suppression
Authors:   Evident Industrial (formerly Olympus Scientific Solutions), Kwan Chi-Hang ,   Evident Industrial (formerly Olympus Scientific Solutions), Lepage Benoit ,   Evident Industrial (formerly Olympus Scientific Solutions), Sun Cong Zhu
Published: July 2023

The objective of the paper is to compare the merits of the multiplication and max value schemes for producing a total focusing method (TFM) representation that combines multiple acoustic modes. We have chosen to compound phase coherence imaging (PCI) images because it eliminates the difficulties associated with handling vastly different acoustic sensitivities across different propagation modes. We also introduce an apodization-based algorithm that can filter out unwanted mode-conversion artifacts that are caused by similarities in time of flights. Experimental data were gathered on an electric resistance welding (ERW) hook crack and a natural bottom-surface-connected vertical crack. Experimental results indicate the multiplication scheme suppresses defect echoes that can only be imaged by a subset of acoustic modes. This can potentially lead to false negatives or underestimation of the extent of the defect. In contrast, the max value scheme retains all indications that appear in a subset of acoustic modes. For the vertical crack configuration imaged by shear wave acoustic modes, the max value scheme retains all mode-conversion artifacts and therefore complicates the defect analysis. The apodization-based filtering method significantly suppressed mode-conversion artifacts without affecting the imaging of the vertical crack. The combination of PCI with max value merging and apodization-based mode-conversion filtering is a promising methodology for merged mode TFM in shear wave weld inspections.
Monitoring of water distribution in meat upon freezing with X-ray computed tomography
Authors:   University of Applied Sciences of Eastern Switzerland, Wolfer Claudio ,   Lucerne University of Applied Sciences and Arts (HSLU), Gwerder Damian ,   Lucerne University of Applied Sciences and Arts (HSLU), Martinez-Garcia Jorge ,   Bergische Universität Wuppertal, Janoske Uwe ,   Lucerne University of Applied Sciences and Arts (HSLU), Schütz Philipp ,   University of Applied Sciences of Eastern Switzerland, Schreiner Michael
Published: July 2023

The freezing speed influences the growth and spatial distribution of ice inf frozen meat. The formation of ice crystals dehydrates the fibres and can damage the cell structure. This influences the drip loss after thawing and reduces tenderness, which is an important eating characteristic of red meat. A better understanding of ice formation and an efficient method for analysing ice distribution can lead to improved freezing processes in food production. This work demonstrates X-ray computed tomography as a novel method suitable for determining and visualising the ice volume fraction in frozen meat, which is important because ice formation has consequences for meat quality (drip loss on thawing, loss of juiciness and tenderness after cooking). The results obtained are in agreement with the phenomenological predictions of the literature and extend the known microscopy methods with a non-destructive and time efficient analysis technique that provides information about the amount of ice formed and its spatial distribution in frozen meat.
Automatic Methods for Ultrasonic Scanning Paths Generation
Authors:   TD NDE, Brassard Michel ,   Centre Technologique en Aérospatiale (CTA), Séguin-Charbonneau Loic ,   Centre Technologique en Aérospatiale (CTA), Walter Julien ,   TD NDE, Cormier Gabriel
Published: July 2023

This paper presents the last evolutions of a program developed in 2020 for the automated generation of optimal scanning paths for 0°LW ultrasonic inspections of complex parts. After summarizing the overall concepts of the path generation method, the paper presents two new algorithms (side following path and side/radius interpolating path) recently developed for specific geometries such as long and thin parts, or parts including nonparallel radii. Trajectories automatically generated by the software are then presented for a collection of various aerospace and industrial CFRP components. The results show that the software was able to generate optimal paths for all the tested geometries, using the part’s 3D surface CAD and the probe’s characteristics as only inputs. In particular, the addition of the new algorithms allows for the generation of satisfactory trajectories even for the parts that were previously problematic.
Influence of Biaxial Stress on Magnetic Behavior of Hot-Rolled Steels
Authors:   Ecole Normale Supérieure de Cachan, Hubert Olivier ,   Ecole Normale Supérieure de Cachan, Taurines Julien ,   Ecole Normale Supérieure de Cachan, Maazaz Zakariae ,   Ecole Normale Supérieure de Cachan, Crepinge Raphaël ,   Centro Nacional de Investigaciones Metalurgicas Madrid  (CENIM), Celada-Casero Carola ,   Tata Steel, Van Den Berg Frenk
Published: July 2023

On-line non-destructive magnetic monitoring (NDM) techniques are relevant to

evaluate the quality of steels and their fluctuations during forming process. The on-line

monitoring faces different issues. Due to magneto-mechanical coupling, stress that may

be applied during NDM may have a strong effect on the magnetic behavior that may lead

to erroneous estimations of the microstructure quality of the material. The multiaxial

character of the stress state is another strong issue. In this communication, some new

results showing the effect of a uniaxial and biaxial stress on the magnetic behavior of 3

grades of hot-rolled steels are presented (from low carbon steel to AHSS).
Deep learning algorithms for design of periodic structures and dispersion curves calculation
Authors:   Changwon National University, Barashok Kseniia ,   Changwon National University, I Boris ,   Changwon National University, Lee Jaesun
Published: July 2023

Periodic structure is useful and powerful tool for the wave manipulation. The

development of design and analysis of periodic structures using traditional methods

(analysis of eigenfrequencies by the finite element method) takes quite a lot of time.

Machine learning and deep learning algorithms can speed up the development and

subsequent analysis of periodic structures. In this work, we consider a particular case of

the propagation of torsional waves in cylindrical objects, the calculation of their

dispersion curves, and methods for generating the design of a unit cell of periodic

structure by a given bandgap configuration. To achieve this goal, autoencoders and

diffusion models were used. A dataset of unit cell shapes and their dispersion curves

were used as training data. First, the dispersion curves were analysed to form a bandgap

configuration, which was then fed to the input of the neural network. The neural

network generates unit cell shape as the output data. Information about dispersion

curves is also very important for the analysis of periodic structures. To calculate the

dispersion curves, the possibility of using deep learning methods is considered - the

problem is the opposite of the previous one. According to the given form, the neural

network should calculate dispersion curves. The paper presents the results of applying

this method for calculating dispersion curves.
NDT & METROLOGY – Improving Efficiency in Aerospace Manufacturing utilizing the Multi-Modality Approach
Authors:   Fill Gesellschaft m.b.H., Gramberger Thomas ,   Fill Gesellschaft m.b.H., Haase Wolfgang
Published: July 2023

Historically, the approach in the aerospace industry has been that the CMM (also known as Metrology) and NDT departments are often independent organizational units, resulting in potential synergies often being recognized late or not at all. Combining NDT with Metrology is the main use case described in this paper, additionally also combinations of complementary NDT modalities like for instance Thermography - Dry and Wet Ultrasonic inspection and much more are possible. This paper is describing the use case of a Multi-Modality Project realized at a TIER 1 Supplier in Germany, but also giving an overview about other possible implementations. Dry inspection alternatives to the classic wet ultrasonic inspection area also mentioned in this paper.
Grinding burn classification with surface Barkhausen noise measurements
Authors:   Tampere University of Technology, Santa-aho Suvi ,   University of Oulu, Sorsa Aki ,   University of Oulu, Ruusunen Mika ,   Tampere University of Technology, Vippola Minnamari
Published: July 2023

Industrial Barkhausen noise (BN) measurements are commonly utilized for final quality control after machining operations such as grinding to point out grinding burns. Grinding burns might compromise the final use and fatigue lifetime of the ground component. The industrial BN method itself is based on a pre-determined threshold value of the BN rootmean-square value (RMS). Elevated RMS values indicate detrimental changes in the component. Usually, the evaluation of grinding burn severity is not carried out. In this study, real ground cylindrical samples were collected that were rejected based on an industrial quality control with a BN unit. A more detailed BN analysis was carried out for 41 individual grinding burn locations followed by X-ray diffraction based residual stress (RS) surface measurements and residual stress and diffraction peak full-width-at-halfmaximum (FWHM) depth profiles. K-means clustering was applied to profiles to label the data points related to grinding burns of different severity. Three classes of grinding burns were identified and verified by micrographs and hardness. A linear discriminant classification model was then identified between the surface BN measurement features and labeled data points. The classification results were reasonable with about 80 % classification accuracy at worst. They showed that the classes identified can be detected with the surface BN measurements. Thus, the approach presented in this paper shows great potential in the practical use of BN measurement where grinding burns can be detected and evaluated with a surface BN measurement.
Inspection benchmarking of Fiber Reinforced Polymers produced by Additive Manufacturing
Authors:   NOVA University of Lisbon, Machado Miguel A. ,   NOVA University of Lisbon, Silva Henrique ,   NOVA University of Lisbon, Pazadinhas João ,   NOVA University of Lisbon, Carvalho Marta S ,   NOVA University of Lisbon, Santos Telmo G.
Published: July 2023

The production of Polymer Matrix Composites (PMCs) through Additive Manufacturing (AM) presents new defects, and the detection of these is crucial for proper functioning. Non-destructive testing (NDT) techniques such as terahertz (THz), air-coupled ultrasounds, and active thermography are fast, automatable, non-invasive, and noncontact inspection methods. The aim of this study is to investigate the use of NDT techniques for detecting defects in PMCs produced by AM. Six samples were produced using polylactic acid (PLA) as the base material and reinforced with continuous fibers of Kevlar, glass, and carbon. Two types of samples were created: one with a full-thickness reinforcement defect in a specific area and the other with a partial reinforcement defect, with a layer of fibers missing in the same area. The samples were then tested using three NDT techniques: THz, non-contact ultrasonic, and active thermography. The results showed that THz was only able to detect the defect in the carbon fiber sample with full-thickness reinforcement, ultrasonic testing was able to detect the defects in Kevlar and carbon fiber samples with missing three layers of fibers, and active thermography was the most reliable technique, detecting all samples with missing three layers of fibers as well as partial reinforcement defects.
Characterization of Microchannels Produced by Friction Stir Channeling: An Experimental Study
Authors:   NOVA University of Lisbon, Machado Miguel A. ,   NOVA University of Lisbon, Sabor Wagner ,   NOVA University of Lisbon, Tasnicenco Ruben ,   NOVA University of Lisbon, Damásio Daniel ,   NOVA University of Lisbon, Santos Telmo G. ,   NOVA University of Lisbon, Vidal Catarina
Published: July 2023

Friction Stir Channeling (FSC) is a recent and innovative solid state manufacturing technology that allows, in a single pass, the opening of continuous internal channels in monolithic components and can be used in the mold and heat exchanger industries. However, the development of reliable Non-Destructive Testing (NDT) for the characterization of the channels is a major challenge. The focus of this work is the non-destructive characterization of micro channels, and the main goal was to experimentally validate which NDT techniques can be used to identify the presence of microchannels, their regularity along the section, and also their location, size, and path. Five NDT techniques were studied: digital radiology; eddy currents; ultrasounds; thermography; and dye penetrants. These techniques were applied to specimens with linear and curvilinear channels. The specimens were produced using tool pins with 0.5 mm diameter which obtained channels with 0.4 mm width and depths of 0.53 mm. Digital radiology and ultrasounds were effective in detecting channels regardless of its dimensions. Eddy currents did not allow to confirm the exclusive presence of the channels due to microstructural changes caused by the FSC process. Thermography using cold fluid injection was not successful in the channel’s characterization due to the extremely low flow. The dye penetrants confirmed the presence of the channels of all dimensions due to the liquid having traveled along the entire path of the curvilinear channel without reaching the surface.
Ultrasonic Spot Weld inspection system based on Industrial Robotic, Artificial Intelligence and Artificial Vision
Authors:   Tecnitest Ingenieros, Pascual Montserrat Acebes ,   Tecnitest Ingenieros, León Iñaki Gauna ,   Tecnitest Ingenieros, Jiménez Héctor de Matías ,   Tecnitest Ingenieros, de Molina Rafael Delgado ,   Tecnitest Ingenieros, de Pablos Alberto Álvarez
Published: July 2023

Nowadays, spot welding is still one of the most frequently used techniques for bonding metal plates, for example, in an automotive chassis between 3000 and 4000 spot welds can be found. Using this technique is possible to obtain at a low cost, easily automated and versatile welds with high quality and speed of operation but, the inspection and quality control process needs to be improved so that it is possible to reach automatic systems that allow maximizing the speed of inspection and guarantee, in turn, the repeatability and accuracy of the results, eliminating possible deviations introduced by the operator. In this paper an inspection system, based on the ultrasonic propagation, is described. The main challenges faced are presented, such as the location of the spot weld, using artificial vision, the definition and positioning of the probes until a reliable signal, and the final analysis through a development based on artificial intelligence. The results achieved in real parts, have shown that this robotic system, has a better defect detection capacity than the systems currently on the market, and is applicable to the inspection on assembly lines, optimizing not only the inspection times but also improving the results and therefore the quality of the process.
Simulation of Eddy Current Rail Testing Data for Neural Networks
Authors:   BAM Federal Institute for Materials Research and Testing, Friedrich Alexander
Published: July 2023

The present work is part of the AIFRI project (Artificial Intelligence For Rail Inspection), where we and our project partners train a neural network for defect detection and classification. Our goal at BAM is to generate artificial ultrasound and eddy current training data for the A.I. This paper has an exploratory nature, where we focus on the simulation of eddy current signals for head check cracks, one of the most important rail surface defects. The goal of this paper is twofold. On the one hand, we present our general simulation setup. This includes geometric models for head check cracks with features like branching and direction change, a model for the HC10 rail testing probe, and the configuration of the Faraday simulation software. On the other hand, we use the Faraday software to simulate eddy current testing signals with a strong focus on the influence of the damage depth on the signal, while differentiating between different crack geometries. Here, we observe an early saturation effect of the test signal at a damage depth of 2 mm (at a crack angle of 25◦ to the surface). That is about 2 mm earlier than we would expect from measurements at a crack angle of 90◦ . This behavior will be investigated further in a future paper. Finally, we interpolate the simulated signals in a two-step curve fitting process. With these interpolations we may generate eddy current test signals for any damage depth within the simulated range.
Automatized Scaling Monitoring in Pipelines with Resonance Testing
Authors:   Technical University of Munich (TUM), Stüwe Isabelle ,   Technical University of Munich (TUM), Pasch Paul O. ,   Technical University of Munich (TUM), Grosse Christian U.
Published: July 2023

Scaling is a significant cause of efficiency loss, downtime and maintenance costs in almost all industries in which pipelines play an integral role. In this work, a non-invasive, cost-effective and automatized monitoring approach to detect the onset and evolution of scaling growth was developed. The designated field of interest was geothermal plants, which particularly struggle with calcitic scaling in Bavaria. An additional criterion that had to be met was therefore applicability at high temperatures. A resonance testing setup, consisting of automatized excitation using a solenoid-based impactor, piezoelectric acceleration sensors coupled to the pipe, an oscilloscope, a signal conditioner and mounting gear, serves to collect a number of amplitude-time signals. These are Fourier transformed, averaged and evaluated in the frequency domain. By coupling the sensors (standard operating temperature limit ~ 120 °C) to the pipe with a high-temperature couplant and samarium-cobalt magnets, the setup is robust in an environment with elevated temperatures. Such an environment is presented by the injection borehole at a geothermal power plant where in-situ measurements are currently being carried out (60 – 80 °C). It can be observed that the frequency peak positions shift with scaling thickness. In order to analyze this shift in frequency, an experiment was conducted in which a heavily scaled piece of pipeline from the production well of a geothermal power plant in Bavaria was inserted in a specially designed descaling test rig. An acidic solution was pumped through the pipe, gradually etching away the calcitic scaling. By carrying out resonance tests at regular time intervals over the course of the descaling process, a continuous reduction in peak frequencies could be determined with decreasing scaling thickness. With an adequately chosen time interval and appropriate measurement parameters (sampling rate, signal length, gain), the onset- and growth of scaling are measurable in the submillimeter regime.
Low Frequency GFRP Imaging with Variable Aperture TFM
Authors:   Sonatest, Nogueira Renato ,   Sonatest, Rioux Philippe ,   Sonatest, Goyette Simon
Published: July 2023

Graphite or glass fiber reinforced polymer (GFRP) inspections are usually made with a zero-degree linear scan (L-scan) (1). Total focusing may not be applicable for some anisotropic materials, but in some cases, TFM may increase the ultrasound imaging quality. The imaging potential of 1D linear probes has been broadened by TFM by many aspects so there is an opportunity to apply the total focusing concepts to exotic composite assessment. The ultrasonic limitations associated with testing thicker sections of GFRP restrict inspections to lower frequency phased array probes. When a low frequency probe uses the L-Scan technique, the performance and sensitivity is negatively affected once compared to a typical phased array probe of a higher frequency due to the element size and pitch restrictions associated with low frequency probes. Therefore, new testing techniques should be found. The alternative imaging acquisition method presented here involves variable aperture receivers that improve the usual LScan characteristics. This study explicitly covers the differences over the L-scan type, the TFM image and its variable aperture TFM feature. In addition of the theory concepts, ultrasound metrics have been recorded on a real GFRP sample and using as reference reflector side drilled holes (SDH).
Low-cost inspection tool for identifying illegal tapping
Authors:   Federal University of Rio de Janeiro (UFRJ), Campos Lucas Braga ,   Federal University of Rio de Janeiro (UFRJ), Camerini Cesar Giron ,   Federal University of Rio de Janeiro (UFRJ), Fernandes Daniel Mendes ,   Federal University of Rio de Janeiro (UFRJ), Silva Vitor Manoel ,   Petrobras Research Center, dos Santos Rafael Wagner Florencio ,   Petrobras Research Center, Morikawa Sergio Ricardo Kokay ,   Federal University of Rio de Janeiro (UFRJ), Pereira Gabriela Ribeiro
Published: July 2023

Pipelines for fuel transportation range in length from hundreds to thousands of kilometers, with part of their length underground. Due to the high cost of the fluids and products transported an increasing number of criminal activities are taking place all over the world. In addition to causing great economic and environmental losses the illegal activity brings risks to the surrounding population. For example, the accident in Tlahuelilpan, Mexico, due to illegal tapping, resulted in the tragedy of hundreds of deaths. In order to combat such activities, many efforts have been employed to early detect and locate illegal tapping in pipelines. The great challenge of such inspections is the unpredictable activity of the clandestine taps, requiring frequent inspections. Usual pipeline inspection tools, such as ultrasound or MFL (Magnetic Flux Leakage) PIG’s, are sensitive for detecting and positioning the anomalies, however, the high operating costs make the recurring application of such tools unfeasible. Focusing on these challenges, a low-cost inspection tool embedded with a minimalist eddy current instrumentation was developed. The results achieved show the capability to detect and differentiate the components existing in the pipeline and illegal taps of different diameters as well as, in a complementary way, the detection of corrosion on the internal surface of the pipelines.
Development of AI based analysis tools for online monitoring of steel-making process
Authors:   Commissariat Energie Atomique (CEA), Miorelli Roberto ,   Commissariat à l’Energie Atomique (CEA), Skarlatos Anastassios ,   Commissariat Energie Atomique (CEA), Reboud Christophe ,   Scuola Superiore Sant'Anna, Vanucci Marco ,   Scuola Superiore Sant'Anna, Mocci Claudio ,   Scuola Superiore Sant'Anna, Colla Valentina ,   Tata Steel, Yang Haibing ,   Tata Steel, Fintelman D. ,   Tata Steel, Ennis Bernard ,   Tata Steel, Van Den Berg Frenk
Published: July 2023

Mechanical properties of steel are closely monitored during the manufacturing process through various non-destructive techniques. The IMPOC device implements one of them and is used by steel manufacturers at several locations of the production line. It provides a fast electromagnetic measurement that is strongly correlated with the microstructural state of the steel, hence its use to check online the uniformity of the semi-final or final product. Tata Steel, CEA LIST and SSSA have worked together to analyse IMPOC datasets corresponding to various situations in terms of steel coils and process conditions. A data driven model has been built from field measurements using a specific neural network architecture. This model proves useful to investigate the complex relations between numerous process parameters and the IMPOC value. This communication presents the approach followed to build the data driven model using neural networks and to check its relevance. The relationship between the measurement on one side and the process parameters and material composition on the other side are then investigated by means of several sensitivity analysis and feature importance techniques.
Tomosynthesis for large additive manufacturing parts
Authors:   Laboratoire National de Métrologie et d'Essais (LNE), Obaton Anne-Françoise ,   X-Ray Imaging Solutions (X-RIS), Koch Damien ,   X-Ray Imaging Solutions (X-RIS), Coline Joachim ,   Institut de Soudure, Flotté Didier
Published: July 2023

X-ray computed tomography (XCT) is up to now the golden method for non-destructive

quality inspection of additively manufacturing (AM) parts. Indeed, the method gets rid of

the complexity of shape and high surface roughness typical of AM parts. However, when

one side of the part is too thick, which happens frequently with parts manufactured with

a direct energy deposition (DED) process implementing a metallic wire and an arc (DEDArc), XCT reaches its limits. Moreover, XCT is a high cost and time-consuming method,

thus alternative quality assurance methods are required. Tomosynthesis appears to be an

interesting alternative solution while the method does not require the X-rays to cross the

thicker section of the part to be inspected. In tomosynthesis, the projections are not

acquired over 360°, but over less than 180°, so it is possible to ensure that the X-ray

source remains on the thinner side of the part to acquire the projections. Then, instead of

proceeding to the reconstruction of a three-dimensional (3D) image, the projections are

assembled and registered by a deblurring algorithm to provide a stack of 2D images on

which a software enables to adjust the focus on each 2D image to analyse the part 2D

image by 2D image in depth.

In this paper, a comparison of X-ray radiography (RT), XCT and tomosynthesis images

reveals the potential of tomosynthesis on a steel DED-Arc flat wall-shaped specimen. The

comparison validates the tomosynthesis images on a part whose thickness still enables

XCT to be performed, to demonstrate the potential of tomosynthesis when XCT reaches

its limits.
Robot-based spot weld inspection - almost couplant-free, imaging phased array based inspection with PHAsis, integrated and automated by ABB Robotics
Authors:   VOGT Ultrasonics GmbH, Köhler Carsten ,   VOGT Ultrasonics GmbH, Vogt Göran ,   ABB AG, Berg Sabine
Published: July 2023

Constant innovations and rethinking of existing systems and processes are essential for the fulfilment of business goals of automotive groups - also for the field of quality assurance. In the context of quality assurance of spot welded joints, the basic tasks of inspection processes are to support the definition of welding parameters, the monitoring of welding results, the optimization of the inspection process and, as a consequence, the reduction of costs and production time. Rigid and manual processes, as they are still used in many areas of quality assurance, are based on laboratory conditions. They are built on general assumptions and are a generic procedure without the possibility of learning processes. If these processes developed in the laboratory encounter production realities, they reach their limits and waste valuable efficiency potential. For example, conventional inspection processes are performed randomly and compare the actual with the target state and, in the event of a deviation, only provide the information of an existing process error. However, this pure information is no longer sustainable for intelligent production and requires a function extension in the sense of Industry 4.0. The goal in the sense of Industry 4.0 in this context is to recognize the root causes of these detected deviations, to provide information in real time and the subsequent intelligent reaction of the system. Artificial intelligence provides a learning system which, based on continuous analysis of production parameters, can not only detect predictive deviations of flexible environmental conditions, but also in a further step autonomously takes action. An example is the detection of weld spatter or sharp-edged areas of spot welds and the subsequent initiated grinding before inspection. This presentation focuses on the development of a robot-controlled module for the almost coupling agent-free inspection of spot welds with innovatively applied phased array technology in production (inline and offline) according to the demands of Industry 4.0.
Modelling Crystallographic Texture Evaluation and Non-Destructive Measurement of Magnetic Anisotropy using an Electromagnetic Sensor in Interstitial Free (If) Steels
Authors:   University of Warwick, Jolfaei Mohsen ,   Cardiff University, Liu Jun ,   University of Warwick, Zhou Lei ,   Tata Steel, Van Den Berg Frenk ,   University of Warwick, Davis Claire
Published: July 2023

Interstitial free (IF) steels are popular in the automotive industry for applications requiring good ductility (formability), strength and a superior surface quality. Magnetic anisotropy measurement can be used to gain information about the crystallographic texture, which is an important property controlling strength and especially the formability, for example rvalues. The crystallographic texture is generated during rolling and subsequent recrystallisation during the annealing heat treatment. A set of IF steel specimens, at different states of recrystallisation (cold rolled, partially recrystallised and fully recrystallised) and accordingly different texture components have been used to investigate measurement and prediction of magnetic anisotropy. A finite element microstructure model that considers crystallographic texture based on magnetic domain theory has been used for the evaluation of magnetic anisotropy in polycrystalline steels. In addition, a laboratory based electromagnetic (EM) U shaped sensor has been proposed to determine the magnetic anisotropy in IF samples by measuring at angles varying from 0° to 90°, in steps of 15°, with respect to the rolling direction. Kernel Average Misorientation (KAM) values from Electron Back Scattered Diffraction (EBSD) characterisation of the samples has been used to evaluate the recrystallisation fraction and correlate that to the texture.
How the EU project “Online Microstructure Analytics” advances inline sensing of microstructure during steel manufacturing
Authors:   Tata Steel, Van Den Berg Frenk ,   Tata Steel, Van Den Berg Frenk ,   Tata Steel, Aarnts Maxim ,   Tata Steel, Yang Haibing ,   Tata Steel, Fintelman F ,   Tata Steel, Ennis Bernard ,   SSAB Europe, Gillgren L ,   CEIT - Centre of Studies & Technical Research of Gipuzkoa, Jorge-Badiola Denis ,   CEIT - Centre of Studies & Technical Research of Gipuzkoa, Martinez-de-Guerenu Ane ,   University of Warwick, Davis Claire ,   University of Warwick, West Graeme ,   University of Warwick, Zhou Lei ,   University of Warwick, Jolfaei Mohsen ,   University of Manchester, Peyton Anthony J ,   University of Manchester, Wilson John W. ,   TNO Science & Industry, Volker Arno ,   TNO Science & Industry, Marina Q ,   TNO Science & Industry, Duijster Arno ,   Swerim AB, Malmström Mikael ,   Swerim AB, Jansson Anton ,   Swerim AB, Hutchinson Bevis ,   Scuola Superiore Sant'Anna, Mocci Claudio ,   Scuola Superiore Sant'Anna, Vannucci M. ,   Scuola Superiore Sant'Anna, Colla Valentina ,   Commissariat Energie Atomique (CEA), Reboud Christophe ,   Commissariat à l’Energie Atomique (CEA), Skarlatos Anastassios ,   Commissariat Energie Atomique (CEA), Miorelli Roberto ,   Altair France, Lombard Patrick ,   Ecole Normale Supérieure de Cachan, Hubert Olivier ,   Ecole Normale Supérieure de Cachan, Taurines Julien ,   University of Grenoble (UJF)-Alpes, Lobanova I ,   University of Grenoble (UJF)-Alpes, Despréaux S ,   Sorbonne Universités, Labbé Stéphane ,   Centro Nacional de Investigaciones Metalurgicas Madrid  (CENIM), Celada-Casero Carola
Published: July 2023

Weight savings in mobility and transport are mandatory in order to reduce CO 2 emissions and energy consumption. The steel industry offers weight saving solutions by a growing portfolio of Advanced High Strength Steel (AHSS) products. AHSS owe their strength to their largely refined and complex microstructures, containing multiple metallurgical phases. Optimal control of the thermo-mechanical processing of AHSS requires inline sensors for real-time monitoring of evolution and consistency of microstructure and material properties. To coordinate and accelerate European development activities in this domain, the project ”Online Microstructure Analytics (OMA)” was established in 2019, constituting of a consortium of 14 specialised research organisations. The EU-funded OMA project, with a total budget exceeding 6 MEU, focuses on inline sensing techniques to monitor the consistency and homogeneity of microstructure, texture and mechanical properties for automotive steels and in particular for AHSS.
Conformable Digital Detector Arrays for Nondestructive Evaluation
Authors:   Carestream Health, Inc., White Brian S.
Published: July 2023

Radiography codes and standards require that the detector be in direct contact with the weld. Until today, only film and computed radiography (CR) could satisfy that requirement for the inspection of oil and gas pipe weld discontinuities. Exposure techniques include but are not limited to double wall single view, single wall single view, or panoramic. An amorphous silicon conformable digital detector array (DDA) that is flexible allows for the detector to be in direct contact with the component. A conformable detector can be bent repeatedly around pipe welds of varying sizes resulting in image quality and workflow time savings productivity benefits for the static capture of welds with curved surfaces. For field radiography applications the detector design must be portable, thin, flexible, easily attached, and able to withstand harsh environments. Size, weight, scintillator type, pixel pitch, bit depth, radiation shielding, load limits, temperature, moisture, atmospheric pressure, vibration mitigation, drop resistance, and ingress protection are all additional considerations. High-quality digital images can be obtained for weld applications utilizing either tethered or wireless image acquisition modes. The improved productivity obtained from bendable detectors relative to film and CR benefit the industry. Discussion of the technology to some real-world radiography applications is presented as part of this paper.
Online Grain Size Measurement by Laser Ultrasonics in a Hot Rolling Mill
Authors:   Arcelor Research, Cousin Guillaume ,   Arcelor Research, Meilland Philip ,   Arcelor Research, Damoiselet Fabienne ,   Arcelor Research, Legrand Nicolas ,   Arcelor Research, Naumann Nils ,   Imagine Optic, Ayeb Adam
Published: July 2023

Laser ultrasonics (LUS) has shown through numerous studies and in-situ laboratory

experiments, its suitability to track microstructural features evolution as well as

metallurgical transformation in steels during thermal cycles with temperatures reaching

1250°C. This prior work has motivated the use of this technology to be in applied in an

industrial hot strip mill (HSM) in Eisenhüttenstadt, Germany. For this purpose, a

transportable trolley which embedded LUS components (Generation and Detection

Lasers, Two-Wave Mixing Interferometer, Dedicated Fibered Optical Head) was

designed. The industrial investigation was carried on moving strips during normal

production at several locations of the HSM, resulting in signals for high-strength lowalloy (HSLA) and advanced high-strength steel (AHSS) grades. The development of a

specific data processing tool allowed calculating the grain size from the analysis of the

online recorded signals. Such results were then compared to predictions from

metallurgical models, finding reasonably close values. LUS appears as a suitable solution

to monitor microstructural features and metallurgical transformations occurring in steel

in a Hot Strip Mill (HSM) line. This approach could enable in the future the development

of more reliable models and control loop of the process. This action was supported by the

European commission and led by a consortium composed by ArcelorMittal, Imagine

Optic and IMI-NRC.
In-situ microstructure monitoring during tempering of quenched AISI4340 steels using a high temperature electromagnetic sensor
Authors:   University of Warwick, Wu Fanfu ,   University of Warwick, Zhou Lei ,   University of Warwick, Davis Claire
Published: July 2023

AISI 4340 steels are used in applications where high strength and toughness are required, for example, in power transmission gears and shafts, aircraft landing gear and other structural components. The required mechanical properties are achieved by hot rolling and quenching and tempering (Q&T) heat treatment. For optimum process efficiency and quality control, it is desirable to monitor the microstructural development during tempering in situ, as the microstructure is directly linked to the mechanical properties. Electromagnetic (EM) sensors have been shown to be sensitive to steel microstructural changes due to the associated changes in magnetic and electrical properties. This study reports on using a high-temperature laboratory EM sensor that operates inside a furnace to assess microstructural changes that occur during tempering at 250°C for AISI4340 steel samples. The sensor operates at low magnetic field and low frequency where the signal is affected by changes in magnetic permeability due to microstructural changes. The microstructure and hardness have been characterised to correlate to the measured EM sensor signal. The results have shown that the EM sensor signal is affected by temperature and microstructural changes on the slow heating to the tempering temperature and then is sensitive to the continuing microstructure changes that occur during the isothermal hold. The results show the potential for in-situ EM sensor monitoring during heat treatment.
Development of HOIS guidance for ultrasonic NDT for non-intrusive inspection at elevated temperatures
Authors:   ESR Technology, Peramatzis Helen ,   ESR Technology, Burch Steve
Published: July 2023

The non-intrusive inspection (NII) of pressure vessels using external in-service ultrasonic NDT has multiple advantages compared to internal visual inspection, including the significant reduction of down-time related costs and safety benefits from avoiding manentry into vessels. The HOIS joint industry project, with support from the Net Zero Technology Centre (NZTC), has recently been focussing on NII of components with operating temperatures of up to 250°C (typical of upstream applications). These inspections are challenging because they require probes to be in contact with the hot surface much longer than for spot thickness measurements. The aim of the work has been to develop recommendations for in-service inspection of components at relatively high operating temperatures, thereby extending the benefits of the NII process, including avoiding or deferring internal visual inspection, to a wider range of vessels. Experimental trials have been performed on test components at up to ~250°C, with an emphasis on scanning ultrasonic systems used for corrosion mapping and weld inspection using TOFD and angled-beam phased-array (PA). The most successful trials gave corrosion mapping and TOFD weld examination results that had similar differences from benchmark values to those achieved in earlier ambient temperature trials. For angled-beam PA, it was found that some trials appeared to have issues with accurate correction of the data for the effects of the elevated component temperature on both the refracted beam angle and signal arrival times. Other trials were more successful in this respect. The lessons learned from trials on both ex-service and manufactured samples are leading to the development of specific guidance for NII at elevated temperatures. The paper highlights the technical challenges associated with ultrasonic scanning systems at elevated temperatures, share the lessons learned from the experimental trials and summarise the guidance developed.
Noncontact measurement of bolt axial force during tightening processes using scattered laser ultrasonic waves
Authors:   Hitachi Ltd, Kitazawa So ,   Hitachi Ltd, Lee Yong ,   University of Nottingham, Patel Rikesh
Published: July 2023

This paper presents a new methodology for noncontact measurement of the axial force

of bolts in their tightening processes using laser-generated ultrasound waves. This

method employs ultrasound waves scattered in a bolt shaft to detect axial force changes,

while most conventional ultrasonic methods use ultrasound waves propagating linearly

along the bolt axis. The ultrasound waves in this study are generated by laser irradiation

on the top surface of a bolt. Subsequently, they propagate deeply into the shaft and

return towards the top of the bolt through complicated paths due to the multiple

scattering in the bolt shaft. Finally, they are detected at the top surface using another

laser and a speckle knife edge detector. With an examination based on the finite element

analysis and verification experiments, it has been shown that the waveform of the

scattered ultrasound shifts in time linearly with increasing the axial force. The time

shifts were estimated using the cross-correlation analysis between the measured

waveforms and the reference waveform with no axial force. This result demonstrates the

feasibility of estimating the change in axial force during tightening processes once the

relationship between the time shifts and axial force is obtained for the specific type of

bolt to be used in products. Furthermore, the proposed technique does not require

machining to flatten a bolt's head and the end, while conventional ultrasonic methods

need the flattening procedures, enabling fast, cost-effective axial force measurement in

mass production manufacturing processes.