Abstract
High-Frequency Eddy Current Techniques (HFEC) refer to special Eddy Current Techniques which work in the frequency range of around 100 kHz to 100 MHz. The techniques are based on the normal Eddy Current technique. Using a coil, an electromagnetic field is induced in the surface of the component, which has to be evaluated. The electromagnetic field induces circling currents, the so called eddy currents. Depending on the electrical properties of the material in the area of this exciting field, a second electromagnetic field is induced, which is directed perpendicular to the exciting field. By analyzing the complex impedance of the measurement coil, variations of the electric properties of the medium can be analyzed. In the higher frequency range of HFEC, special sensors and hardware filters must be used. HFEC is better suited for applications in materials with very low electrical conductivity, such as titanium alloys, nickel-based superalloys and similar materials, Carbon composites, ceramic composites, and polymers and lossy dielectrics may be evaluated as well. With HFEC, it is possible to reach an improvement in the measurement effect as well as better lateral resolution with matching penetration depths for these applications in comparison to lower eddy current frequencies. Additionally, the measurement effect is not only influenced by inductive processes in the area affected by the eddy currents but also by capacitive effects and an increase in displacement currents, which increases the gathered information as well. Regarding the applications, measurement process, sensors and hardware, different specifics must to be considered.
References
Abu-Nabah B, Nagy PB (2007) Lift-off effect in high-frequency eddy current conductivity spectroscopy. NDT&E Int 40:555–565
Abu-Nabah BA, Yu F, Hassan WT, Blodgett MP, Nagy PB (2009) Eddy current residual stress profiling in surface-treated engine alloys. Nondestruct Test Eval 24:209
Blodgett MP, Nagy PB (2004) Eddy current assessment of near-surface residual stress in shot-peened nickel-base superalloys. J Nondestruct Eval 23:107–123
Gäbler S et al (2015a) Quantitatively analyzing dielectrical properties of resins and mapping permittivity variations in CFRP with high-frequency Eddy current device technology. In: 41st annual review of progress in quantitative nondestructive evaluation, AIP conference proceeding, vol 1650, pp 336–344. AIP Publishing LLC. https://doi.org/10.1063/1.4914628. 978-0-7354-1292-7
Gäbler S et al (2015b) Measuring and imaging permittivity of insulators using high-frequency Eddy-current devices. IEEE transducers on instrumentation and measurement, 0018-945, IEEE
Heuer H, Hillmann S, Röllig M, Schulze M, Wolter K-J (2009) Thin film characterization using high frequency eddy current spectroscopy. In: 9th IEEE conference on nanotechnology, NANO 2009, pp 165–168. Conference on nanotechnology (NANO)’9, Genoa
Heuer H, Schulze M, Pooch M, Gäbler S (2015) Process monitoring for resins, carbon fiber fabrics, preforms and consolidation by HF radio wave techniques. In: 14th international symposium on nondestructive characterization of materials (NDCM 2015) June 2226, Marina Del Rey
Hillmann S, Heuer H, Baron H-U, Bamberg J, Meyendorf N (2008) Near-surface residual stress-profiling with high frequency eddy current conductivity measurement. In: 35th annual review of progress in quantitative NDE, QNDE. Chicago 20–25 July
Hillmann S, Dayoub R, Röllig M, Meyendorf N, Heuer H (2010) High-frequency Eddy current conductivity measurement for near-surface layer characterization. In: Knopp J et al (eds) Electromagnetic nondestructive evaluation (XIII). IOS Press BV, Netherlands, pp 79–86
Jia Y, Heuer H, Hillmann S, Meyendorf N (2009) Stray capacitances of an air-cored Eddy current sensor. Sensor Transducers J 111(12):25–37
Kyrychenko M et al (2016) NDT investigations on C/SiC samples from different manufacturing steps. In: Proceedings of the 8th international symposium on NDT in aerospace, 3–5 Nov
Lange R, Mook G (1994) Structural analysis of CFRP using eddy current methods. NDT&E Int 27(5):241–248
Langhof N, Krenkel W (2017) Ceramic matrix composites for high performance friction applications. In: Proceedings of the IV advanced ceramics and applications conference, Jan 2017, pp 13–28. https://doi.org/10.2991/978-94-6239-213-7_2
Schulze M-H, Heuer H, Küttner M, Meyendorf N (2010) High-resolution eddy current sensor system for quality assessment of carbon fiber materials. Microsyst Technol 16(5):791–797
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Hillmann, S., Schulze, M.H., Heuer, H. (2018). High-Frequency Eddy Current Techniques. In: Ida, N., Meyendorf, N. (eds) Handbook of Advanced Non-Destructive Evaluation. Springer, Cham. https://doi.org/10.1007/978-3-319-30050-4_49-1
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DOI: https://doi.org/10.1007/978-3-319-30050-4_49-1
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