TY - CONF A1 - Kreutzbruck, Marc A1 - Allweins, K. A1 - Strackbein, C. A1 - Bernau, H. T1 - High Resolution Eddy Current Testing of Superconducting Wires using GMR-Sensors T2 - 17th World Conference on Non-Destructive Testing CY - Shanghai, China DA - 2008-10-25 KW - GMR-sensor KW - Eddy Current Testing KW - Reconstruction KW - Superconducting wires PY - 2008 IS - Paper 389 SP - 1 EP - 6 PB - International Committee for Non-Destructive Testing CY - Shanghai AN - OPUS4-18434 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kreutzbruck, Marc A1 - Allweins, K. A1 - Bernau, H. ED - Peter Scharff, T1 - Inverse Algorithm for Electromagnetic Wire Inspection based on GMR-Sensor Arrays T2 - 10th Workshop on optimization and inverse problems in electromagnetism (OIPE 2008) CY - Ilmenau, Germany DA - 2008-09-14 KW - Nondestructive Testing KW - Reconstruction KW - GMR-sensor array KW - Superconducting wires PY - 2008 IS - O6_1 SP - 137 EP - 138 CY - Ilmenau AN - OPUS4-18367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kreutzbruck, Marc A1 - Brekow, Gerhard A1 - Böhm, R. A1 - Montag, Hans-Joachim A1 - Allweins, K. A1 - Strackbein, C. A1 - Bernau, H. T1 - Visualization of material defects - modern approaches in acoustical and electrical NDE-methods N2 - Increasing demands in materials quality and cost effectiveness have led to advanced standards in manufacturing technology. Especially when dealing with high quality standards in conjunction with high throughput quantitative NDE techniques are vital to provide reliable and fast quality control systems. Fast NDE-systems using a high degree of automatisation can be used for both determining the degree of integrity of the components under test and indicating a change of production parameters as well. However, independently of the applied NDE method and the underlying physical principle a reliable visualisation of hidden defects within the component under test is based on a sufficient high signal to noise ratio (SNR) and a high spatial resolution. In this talk we illuminate two standard NDT methods such as Ultrasonic Testing and Eddy Current Testing and show their physical principles also discussing the interaction between sound waves or induced eddy currents with different kinds of material defects. This introduction substantiates the attainable SNR and spatial resolution of both methods with respect to defect sizing and defect classification. As a first future prospect we report on the SAFT-algorithm to improve SNR and spatial resolution paving the way for a flaw sizing approach in ultrasonic inspection. As a second modern NDE approach we represent the use of small magnetoresistance sensor arrays for EC testing of Al-laser welds or for testing superconducting wires. The high sensitivity and small extent of GMR sensors results in a remarkably SNR and spatial resolution offering new visualisation techniques for defect localisation, defect characterization and tomography-like mapping techniques. T2 - ICAMT 2008 - International Conference on Advances in Manufacturing Technology for Young Engineers CY - Madras, Chennai, India DA - 2008-02-06 PY - 2008 IS - CD-ROM (A.4 / I-1) SP - 1 PB - Indian National Academy of Engineering (INAE) CY - Madras, Chennai, India AN - OPUS4-17622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kreutzbruck, Marc A1 - Bernau, H. A1 - Allweins, K. T1 - Hochauflösende Wirbelstromprüfung mittels GMR-Sensorik am Beispiel supraleitender Drähte N2 - Aufgrund eines anhaltenden Trends der Miniaturisierung von Bauteilen sowie eines gesteigerten Qualitätsanspruches in Fertigung und Instandhaltung besteht ein wachsender Bedarf für hochauflösende zerstörungsfreie Prüfverfahren. Ein derzeit vielversprechender Lösungsansatz in der elektromagnetischen Prüfung wird durch die magnetischen Mikrosysteme eröffnet. Insbesondere die jüngst mit dem Physik-Nobelpreis ausgezeichnete GMR-Technologie bietet neben einer hohen Feldempfindlichkeit zugleich hervorragende Ortsauflösungen mit Schichtabmessungen bis in den unteren µm-Bereich. Hierdurch werden magnetische Feldverteilungen bei der Wirbelstromprüfung oder der Streuflussprüfung mit einem gegenüber Spulensystemen erhöhten Signal/Rausch-Verhältnis (SNR) und einer verbesserten Ortsauflösung gemessen. Im vorliegenden Beitrag wird das Potenzial der MR-Technologie anhand der Wirbelstromprüfung von Drähten verdeutlicht. Hierbei wird ein kreuzförmiges GMR-Sensor-Array um den zu untersuchenden Draht positioniert. Jeder einzelne GMR-Sensor misst dabei mit einer Feldempfindlichkeit von etwa 200pT/√Hz und einer Ortsauflösung von 100µm. Der Nachweis von im Durchmesser etwa 200µm großen Defekten in einer Tiefenlage von 200µm unterhalb der Drahtoberfläche gelingt mit einem SNR von über 400. Oberflächendefekte ähnlicher Größenordnung können mit einem SNR von nahezu 104 detektiert werden. Ein derart hohes SNR birgt in Kombination mit der hohen örtlichen Auflösung Potenzial für eine 3D-Fehlerlokalisierung. Unter Verwendung eines analytischen Ansatzes sowie auf FEM beruhende Dateninversionsalgorithmen können Defekte mit einer Abmessung von größer 200µm auf einige 10µm exakt lokalisiert werden. KW - GMR-Effekt KW - Sensor-Array KW - Wirbelstromprüfung KW - Drahtprüfung KW - Finite-Elemente-Methode KW - Rekonstruktion KW - GMR effect KW - Eddy current KW - Superconducting wire KW - Finite elements method KW - Reconstruction PY - 2008 DO - https://doi.org/10.1524/teme.2008.0879 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 75 IS - 9 SP - 477 EP - 484 PB - Oldenbourg CY - München AN - OPUS4-18002 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kreutzbruck, Marc A1 - Bernau, H. A1 - Allweins, K. A1 - Strackbein, C. T1 - Untersuchung zur 3D-Magnetotomographie in der Drahtprüfung mittels hochauflösendem GMR-Wirbelstromprüfsystem T2 - DGZfP-Jahrestagung 2007 CY - Fürth, Deutschland DA - 2007-05-14 KW - Magnetische Mikrosysteme KW - GMR-Sensor-Array PY - 2007 SN - 978-3-931381-98-1 SP - 1 EP - 9 (Poster 62) PB - DGZfP CY - Berlin AN - OPUS4-16449 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kreutzbruck, Marc A1 - Thomas, Hans-Martin A1 - Sickert, Roland A1 - Casperson, Ralf A1 - Boehm, Rainer A1 - Allweins, K. A1 - Lemke, G. T1 - A numerical study of the inclusion problem in electromagnetic testing KW - FEM KW - Eddy Current Testing (ECT) KW - Eddy Current (EC) PY - 2009 SN - 0025-5300 VL - 51 IS - 11-12 SP - 819 EP - 827 PB - Hanser CY - München AN - OPUS4-20507 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kreutzbruck, Marc A1 - Thomas, Hans-Martin A1 - Casperson, Ralf A1 - Reimund, Verena A1 - Blome, Mark A1 - Allweins, K. A1 - Lembke, G. T1 - Magnetic response field of spherical defects on non-destructive evaluation T2 - NDE 2009 CY - Tiruchirappalli, India DA - 2009-12-10 KW - Electromagnetic testing KW - Spherical defects KW - Finite element method PY - 2009 SP - 271 EP - 275 AN - OPUS4-20831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kreutzbruck, Marc A1 - Thomas, Hans-Martin A1 - Casperson, Ralf A1 - Reimund, Verena A1 - Blome, Mark A1 - Allweins, K. A1 - Lembke, G. ED - Mazal, Pavel T1 - Magnetic response field of spherical defects within conductive components T2 - 5th International workshop of NDT experts - NDT in progress 2009 CY - Prague, Czech Republic DA - 2009-10-12 KW - Electromagnetic testing KW - Spherical defects KW - Finite element method PY - 2009 SN - 978-80-214-3968-9 SP - 163 EP - 172 AN - OPUS4-20336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kreutzbruck, Marc A1 - Thomas, Hans-Martin A1 - Casperson, Ralf A1 - Reimund, Verena A1 - Blome, Mark A1 - Allweins, K. A1 - Lembke, G. ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Magnetic response field of spherical defects within conductive components N2 - The determination of magnetic distortion fields caused by inclusions hidden in a conductive matrix using homogeneous current flow needs to be addressed in multiple tasks of electromagnetic non-destructive testing and materials science. This includes a series of testing problems such as the detection of tantalum inclusions hidden in niobium plates, metal inclusion in a nonmetallic base material or porosity in aluminum laser welds. Unfortunately, straightforward tools for an estimation of the defect response fields above the sample using pertinent detection concepts are still missing. In this study the Finite Element Method (FEM) was used for modeling spherically shaped defects and an analytical expression developed for the strength of the response field including the conductivity of the defect and matrix, the sensor-to-inclusion separation and the defect size. Finally, the results also can be useful for Eddy Current Testing problems, by taking the skin effect into consideration. T2 - 36th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Kingston, RI, USA DA - 2009-07-26 KW - Electromagnetic testing KW - Spherical defects KW - Finite element method PY - 2010 SN - 978-0-7354-0748-0 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings SP - 1 EP - 8 CY - Melville, NY AN - OPUS4-21815 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kreutzbruck, Marc A1 - Allweins, K. A1 - Strackbein, C. A1 - Bernau, H. ED - Thompson, D. O. ED - Chimenti, D. E. T1 - High resolution eddy-current wire testing based on a GMR sensor-array N2 - Increasing demands in materials quality and cost effectiveness have led to advanced standards in manufacturing technology. Especially when dealing with high quality standards in conjunction with high throughput quantitative NDE techniques are vital to provide reliable and fast quality control systems. In this work we illuminate a modern electromagnetic NDE approach using a small GMR sensor array for testing superconducting wires. Four GMR sensors are positioned around the wire. Each GMR sensor provides a field sensitivity of 200 pT/√Hz and a spatial resolution of about 100 µm. This enables us to detect under surface defects of 100 µm in size in a depth of 200 µm with a signal-to-noise ratio of better than 400. Surface defects could be detected with a SNR of up to 10,000. Besides this remarkably SNR the small extent of GMR sensors results in a spatial resolution which offers new visualisation techniques for defect localisation, defect characterization and tomography-like mapping techniques. We also report on inverse algorithms based on either a Finite Element Method or an analytical approach. These allow for accurate defect localization on the µm scale and an estimation of the defect size. T2 - 35th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Chicago, IL, USA DA - 2008-07-20 KW - GMR KW - Eddy current testing KW - Reconstruction KW - FEM PY - 2009 SN - 978-0-7354-0629-2 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1096 SP - 1695 EP - 1702 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-19437 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kreutzbruck, Marc A1 - Allweins, K. A1 - Strackbein, C. A1 - Bernau, H. T1 - Inverse algorithm for electromagnetic wire inspection based on GMR-sensor arrays N2 - To meet the increasing fabrication quality standards and the high throughput requirements NDE techniques are reliant on efficient reconstruction tools and visualization tools. In this work we present an inverse algorithm for a modern electromagnetic non-destructive testing approach using a small GMR sensor array to inspect superconducting wires. Four sensitive GMR sensors are positioned around the wire. Small defects of 100 µm in size could be detected in a depth of 200 µm with a signal-to-noise ratio of better than 400. Surface defects could be detected with a SNR of up to 10,000. This remarkably SNR and the small extent of GMR sensors results in a spatial resolution which offers new visualisation techniques for defect localisation, defect characterization and future tomography-like mapping techniques. We developed several inverse algorithms based on either a Finite Element Method or an analytical approach leading to defect localization with an accuracy of a few 10 µm. KW - Nondestructive testing KW - Reconstruction KW - GMR-sensor array KW - Superconducting wires PY - 2009 DO - https://doi.org/10.3233/JAE-2009-1030 SN - 1383-5416 SN - 0925-2096 VL - 30 IS - 3-4 SP - 299 EP - 308 PB - IOS Press CY - Amsterdam, The Netherlands AN - OPUS4-20273 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -