TY - CONF A1 - Gornushkin, Igor B. T1 - Modeling Equilibrium Chemistry in Laser Induced Plasmas and Plasma Chemical Reactors N2 - A brief introduction will be given on modeling chemical reactions in laser induced plasmas using stoichiometric and non-stoichiometric approaches. Several applications will be considered, which can benefit from such modeling. Those include plasma enhanced chemical vapor deposition (PECVD), surface modification and surface coating, and molecular analysis by LIBS. Each application will be illustrated by simulations of relevant chemical systems. For PECVD, chemical systems are BCl3/H2/Ar, BF3/H2/Ar, BCl3/BF3, Mo/BF3/H2; for surface modification/coating it is Ti/air; for molecular LIBS they are CaCO3/Ar, Ca(OH)2/Ar, and CaCl2/Ar. Advantages and shortcomings of equilibrium chemical hydrodynamic models of laser induced plasmas will be discussed. T2 - 1st NIP Conference National Institute of Physics (IKF), the Albanian Academy of Sciences CY - Online meeting DA - 10.02.2022 KW - Laser ablation KW - Laser induced plasma deposition KW - Surface coating KW - Titanium dioxide KW - Emission spectroscopy KW - Hydrodynamic model KW - Plasma chemistry PY - 2022 AN - OPUS4-54328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Plasma Fundamentals and Diagnostics N2 - This course will provide an introduction to plasma diagnostic techniques. The major focus of the course will be on the discussions of the practical procedures as well as the underlying physical principles for the measurements of plasma fundamental characteristics (e.g., temperatures and electron number density). Particular emphasis will be placed on laser induced plasma–atomic emission spectrometry, but other analytical plasmas will also be used as examples when appropriate. Selected examples on how one can manipulate the operating conditions of the plasma source, based on the results of plasma diagnostic measurements, to improve its performance used for spectrochemical analysis will also be covered. Topics to be covered include thermal equilibrium, line profiles, temperatures, electron densities, excitation processes, temporal and spatial resolution. T2 - 2022 Winter Conference on Plasma Spectrochemistry CY - Tucson, Arizona, USA DA - 17.01.2022 KW - Thermal equilibrium KW - Excitation processes KW - Electron number density KW - Temperatures KW - Spatial information KW - Emission line profiles PY - 2022 AN - OPUS4-54288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Held, Mathias T1 - Inverse determination of elastic material parameters from the propagation behavior of ultrasonic waves using convolutional neuronal networks N2 - Um aus messtechnisch ermittelten Dispersionsabbildungen geführter Ultraschallwellen Rückschlüsse auf die Materialparameter zu ziehen, werden in der aktuellen Forschung verschiedene inverse Methoden diskutiert. Maschinelles Lernen und insbesondere Convolutional-Neural-Networks (CNNs) stellen eine Möglichkeit der automatisierten inversen Modellierung und Evaluierung von Bilddaten dar. In diesem Vortrag wird anhand synthetischer Daten gezeigt, wie das Ausbreitungsverhalten von geführten Ultraschallwellen unter Verwendung von CNNs genutzt werden kann, um die isotropen elastischen Konstanten einer plattenförmigen Struktur zu bestimmen. T2 - Doktorandentreffen 2021 CY - Petershagen/Eggersdorf, Germany DA - 25.10.2021 KW - Convolutional Neuronal Networks KW - Inverse Probleme KW - Materialcharakterisierung KW - Maschine learning KW - Guided waves KW - Lamb Wellen PY - 2021 AN - OPUS4-54264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hassenstein, Christian T1 - Adaptive TFM approach for turbine blade testing in an NDE 4.0 environment N2 - Turbine blades for gas turbines are exposed to extreme working conditions in a demanding environment. In-service inspection, maintenance and refurbishment of the heavily stressed parts is necessary to ensure both safety and efficiency, e.g. based on immersion ultrasound testing (UT). In the course of NDE 4.0, the European project MRO 2.0 aims to innovate the maintenance, repair and overhaul of turbine blades by linking these with modern digital methods. For this, the goal of this project is to go beyond conventional automated and manual UT testing techniques. The aim is to measure the actual geometry and wall thickness of the complex shaped parts by applying an adaptive TFM that takes into account the refraction of the ultrasonic waves at the transition from the coupling material (water) to the inspected part (steel). In this setup the phased array probe is held by a robotic arm that allows the part to be scanned while remaining mainly perpendicular to the inspected surface. In this way, even complex geometries can be inspected and a 3D model of the actual condition of the part can be created. The laboratory setup is equipped with a Vantage 64 phased array instrument from Verasonics Inc. and an industrial robot from ABB. A 64 element linear array probe operating at 10 MHz is attached to the robot. The focus is on optimizing resolution, reliability and inspection speed, as the reconstructed model will be fed to the digital twin at a later stage of the project and used for targeted repairs. In addition to enhancing the reconstruction algorithms, required probe geometry and the parameters needed to inspect turbine blades with partially thin walls and anisotropic materials will also be investigated. This talk will describe the 3-year project and present the results of the first year. The main focus will be on the development of the reconstruction algorithms used and the experimental setup. T2 - 48th Annual Review of Progress in Quantitative Nondestructive Evaluation (QNDE 2021) CY - Online meeting DA - 28.07.2021 KW - Utrasound testing KW - Turbine blade KW - Maintenance KW - Phased array KW - Automation PY - 2021 AN - OPUS4-54313 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Deposition of Titanium Oxides by Nanosecond Laser Ablation: Simulation and Experiment N2 - Surface modification of titanium by laser ablation is investigated theoretically and experimentally. The modification consists in texturing the surface and redeposition of chemically transformed material from the ablation plasma. The redeposition is driven by the hydrodynamic flow in the plasma. Such surface modification improves the biocompatibility of titanium implants. T2 - 2022 Winter Conference on Plasma Spectrochemistry CY - Tucson, Arizona, USA DA - 17.01.2022 KW - Laser ablation KW - Laser induced plasma deposition KW - Surface coating KW - Titanium dioxide KW - Emission spectroscopy KW - Hydrodynamic model KW - Plasma chemistry PY - 2022 AN - OPUS4-54289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - In situ investigations of mechanochemical processes N2 - Overview of the present BAM activities in the field of in situ analytics of mechanochemical processes. Recent results for the synthesis of metal organic frameworks and cocrystals are presented. T2 - HZB Seminar CY - Online meeting DA - 21.01.2022 KW - Mechanochemistry KW - In situ real-time monitoring PY - 2022 AN - OPUS4-54296 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gornushkin, Igor B. T1 - Optical Detection of Defects during Laser Metal Deposition N2 - Laser metal deposition is a rapidly evolving method for additive manufacturing that combines high performance and simplified production routine. Quality of production depends on an instrumental design and operational parameters, which require constant control during the process. In this work, feasibility of using optical spectroscopy as a control method is studied via modeling and experimentally. A simplified thermal model is developed based on the time-dependent diffusion-conduction heat equation and geometrical light collection into detection optics. Intense light emitted by a laser-heated spot moving across a sample surface is collected and processed to yield the temperature and other temperature-related parameters. In the presence of surface defects, the temperature field is distorted in a specific manner that depends on shape and size of the defect. Optical signals produced by such the distorted temperature fields are simulated and verified experimentally using a 3D metal printer and a sample with artificially carved defects. Three quantities are tested as possible metrics for monitoring the process: temperature, integral intensity, and correlation coefficient. The shapes of the simulated signals qualitatively agree with the experimental signals; this allows for a cautious inference that optical spectroscopy can detect surface defects and, possibly, predict their characters, e.g., inner or protruding. T2 - Colloquium Spectroscopicum Internationale XLII (CSI XLII) CY - Gijon, Spain DA - 30 May 2022 KW - Additive manufacturing KW - Laser metal deposition KW - Optical sensor KW - Optical emission spectroscopy KW - Process control PY - 2022 AN - OPUS4-55063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brauckmann, C. A1 - Pramann, A. A1 - Rienitz, O. A1 - Schulze, A. A1 - Phukphatthanachai, P. A1 - Vogl, Jochen T1 - Combining Isotope Dilution and Standard Addition - Elemental Analysis in Complex Samples N2 - A new method combining isotope dilution mass spectrometry (IDMS) and standard addition has been developed to determine the mass fractions w of different elements in complex matrices: (a) silicon in aqueous tetramethylammonium hydroxide (TMAH), (b) sulfur in biodiesel fuel, and (c) iron bound to transferrin in human serum. All measurements were carried out using inductively coupled plasma mass spectrometry (ICP–MS). The method requires the gravimetric preparation of several blends (bi)—each consisting of roughly the same masses (mx,i) of the sample solution (x) and my,i of a spike solution (y) plus different masses (mz,i) of a reference solution (z). Only these masses and the isotope ratios (Rb,i) in the blends and reference and spike solutions have to be measured. The derivation of the underlying equations based on linear regression is presented and compared to a related concept reported by Pagliano and Meija. The uncertainties achievable, e.g., in the case of the Si blank in extremely pure TMAH of urel (w(Si)) = 90% (linear regression method, this work) and urel (w(Si)) = 150% (the method reported by Pagliano and Meija) seem to suggest better applicability of the new method in practical use due to the higher robustness of regression analysis. T2 - CITAC Best Paper Award Ceremony CY - Online meeting DA - 21.06.2022 KW - Isotope dilution mass spectrometry KW - Standard addition KW - ICP-MS KW - Blank characterization KW - Silicon KW - Sulfur KW - Transferrin KW - Tetramethylammonium hydroxide KW - Biodiesel fuel KW - Human serum PY - 2022 AN - OPUS4-55032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pech May, Nelson Wilbur T1 - Automatic inspection of surface breaking cracks using laser scanning thermography N2 - In this work, we report on a method for automatic inspection of components using laser scanning thermography, in which the relative motion is performed by a robot to fully inspect complex test objects such as turbine blades. We demonstrate our evaluation algorithms with the aim of automatically detecting surface defects on calibrated specimens. We show the influence of the excitation laser, which can be varied in terms of spot geometry, wavelength, and scan scheme. Additionally, we show some advantages, versatility, and current challenges of using a programmed robot for non-destructive evaluation in thermography. T2 - International Conference in Photoacoustics and Photothermal Phenomena (ICPPP21) CY - Bled, Slovenia DA - 19.06.2022 KW - Flying line thermography KW - Surface breaking defects KW - Canny approach PY - 2022 AN - OPUS4-55386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kröll, Mirco T1 - Effects of harmonised procedures in tribology testing N2 - i-TRIBOMAT will provide the world's first Open Innovation Test Bed dedicated to analysing and simulating materials in tribological systems. In order to make necessary results of tribological tests comparable, harmonised ways to produce data are mandatory. Many sources influence the outcome of a Tribological test. Different approaches of institutes were evaluated in best practices via quality management tools minimising the impact on results. T2 - 7th World Tribology Congress - WTC 2022 CY - Lyon, France DA - 11.07.2022 KW - Tribology KW - i-TRIBOMAT KW - Characterisation KW - Digitalisation KW - Harmonisation KW - Round robin tests KW - Interlaboratory tests PY - 2022 AN - OPUS4-55317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -