Barkhausen Noise Analysis Research Articles

Development of soft magnetic composites for low-loss applications

Soft magnetic composite materials have been pressed into cylinders using both monotonic and cyclic loading over the pressure range 200–800 MPa. Some samples have subsequently been heat treated over the temperature range 200–600°C. Magnetic Barkhausen noise (MBN) analysis has been used to look at the effects of these various processing stages. Increasing pressing pressure shows an increase in the MBN peak signal. Cyclic pressed samples exhibited larger values of peak MBN signal than the equivalent monotonic load. Subsequent heat treatments decreased the MBN signal. The changes in MBN signal are attributed to the strain-induced changes in domain alignment in the adjacent grains during the pressing process.

Barkhausen noise analysis for stress field evaluation on bearing raceway used in aeronautic engine

SNFA has decided to develop the Barkhausen noise technique in order to determine the state of stresses and the microstructural changes in the contact zones of the bearing raceways and rolling elements. Based on its know-how, its practical experience

Application of the wavelet transform in mechanical spectroscopy and in Barkhausen noise analysis

In this work, the wavelet transform and the Fast Fourier Transform FFT are introduced to analyze the quality of the strain response signal in order to improve the accuracy of computation of both the logarithmic decrement and the mechanical loss angle. The wavelet transform of the strain response signal yields a three-dimensional representation (the time-scale joint representation), i.e. space (time), frequency (scale) and amplitude. To emphasize that not only time but also frequency content of the strain response signal collected from a mechanical spectrometer is identified, the author suggests that the time-scale joint representation of the strain response signal should be called ‘Identified Strain Response Signal — ISRS’. The wavelet transform was shown to be an excellent tool to test the quality of the strain and/or of the stress signal in a mechanical spectrometer working in a resonant or subresonant mode. A new approach to the non-stationary Barkhausen noise (BN) signal based on the wavelet transform is also presented. The BN level is usually expressed with the magnetoelastic parameter MP which is a relative number proportional to the root mean square level of the BN. It was found that the MP value is not a reliable parameter for the identification of stress concentrations in ferromagnetic materials. Indeed, a stress concentration resulting from internal stresses can be successfully revealed by the time-scale joint representation of the BN signal. The author suggests that the wavelet transform of the non-stationary RN signal should be called the ‘Identified Barkhausen Noise — IBN’. This approach produces a physically reliable relationship between the IBN and either the level of internal stresses or fine variations in the microstructure.

Microstructural characterization of quenched and tempered 0.2% carbon steel using magnetic Barkhausen noise analysis

Magnetic Barkhausen noise (MBN) has been used to characterize the microstructures in quenched and tempered 0.2% carbon steel. It has been observed that tempering at 873 K shows a single peak MBN behaviour after 0.5 h and a slope change indicating the development of two peak behaviour after 1 h. After 5 h of tempering, MBN shows a clear two peak behaviour. A two stage process of irreversible domain wall movement during magnetization is proposed considering the grain boundaries and second phase precipitates as the two major obstacles to domain wall movement. The domain walls overcome these two major obstacles over a range of critical field strengths with some mean values characteristic of the obstacles. If these two mean values are close to each other, then a single peak, sometimes associated with a slope change in MBN behaviour, appears. On the other hand, if the mean values of the critical fields of these two barriers are widely separated, then a two peak behaviour appears. The effect of microstructural changes on MBN is explained based on these two stage processes. The influence of dissolution of martensite and the precipitation of cementite (Fe 3C) on MBN are explained.

Non-destructive estimation of fatigue damage for steel by Barkhausen noise analysis : 60308 Tomita, Y.; Hashimoto, K.; Osaw, N.; Inai, H. proceedings of the Special Offshore Symposium China (SOSC-'94/PACOMS- 94), Beijing, China 17–18 Apr. 1994. pp. 195–203. Edited by Y.C. Li and J.S. Chung. The international society of offshore and polar engineers (1994). ISBN 1-880653-15-X

Non-destructive estimation of fatigue damage for steel by Barkhausen noise analysis : 60308 Tomita, Y.; Hashimoto, K.; Osaw, N.; Inai, H. proceedings of the Special Offshore Symposium China (SOSC-'94/PACOMS- 94), Beijing, China 17–18 Apr. 1994. pp. 195–203. Edited by Y.C. Li and J.S. Chung. The international society of offshore and polar engineers (1994). ISBN 1-880653-15-X

Non-destructive evaluation of cooling rate and toughness in hot-work tool steel quenched from various austenitization temperatures by Barkhausen noise analysis (In Japanese: English Abstract) : 46950 Nakai, N.; Obata, M. Tetsu to Hagane, Vol. 77, No. 1, pp. 147–154 (1991)

Non-destructive evaluation of cooling rate and toughness in hot-work tool steel quenched from various austenitization temperatures by Barkhausen noise analysis (In Japanese: English Abstract) : 46950 Nakai, N.; Obata, M. Tetsu to Hagane, Vol. 77, No. 1, pp. 147–154 (1991)

Nondestructive estimation of fatigue damage for steel by Barkhausen noise analysis

Magnetic Barkhausen noise (BHN) signals are detected when magnetized domain walls move discontinuously in a ferromagnetic material. This non-uniform motion is sensitive to the microstructures of material which vary continuously with the increase of applied stress and loading cycles. In this paper, the possibility of evaluation of residual fatigue life under cyclic loading conditions is discussed based on BHN analysis. The material used in the test is mild steel. Both static loading tests and load-controlled axial pulsating fatigue tests are performed on plain plate specimens. The BHN signals are measured for each increment of tensile load during static tests and for each interval of cyclic loading during fatigue tests. The main results obtained are as follows: (1) When the applied stress range is below the fatigue limit, the BHN signal keeps nearly constant. (2) When the applied stress range is above the fatigue limit, the ratio of the BHN peak voltage of the stress level S to 0 MPa at the Nth cycle, V ns V n 0 , varied clearly with loading cycles. (3) The procedure of residual life prediction is proposed.

Non-destructive cooling rate evaluation of 0.4 C-5 CrMoV hot-work tool steel by Barkhausen noise analysis (In Japanese: English abstract) : 42290 Nakai, N.; Obata, M. Tetsu to Hagane (Journal of the Iron and Steel Institute of Japan), Vol. 75, No. 5, pp. 833–840 (May 1989)

Non-destructive cooling rate evaluation of 0.4 C-5 CrMoV hot-work tool steel by Barkhausen noise analysis (In Japanese: English abstract) : 42290 Nakai, N.; Obata, M. Tetsu to Hagane (Journal of the Iron and Steel Institute of Japan), Vol. 75, No. 5, pp. 833–840 (May 1989)

Magnetic Barkhausen Noise analysis for the assessment of microstructures in heat treated 2.25CR-1Mo and 17-4-PH steels : 51003 Bhattacharya, D.K.; Vaidyanathan, S.; Moorthy, V.; Jayakumar, T.; Raj, B. Non-Destructive Testing 92. Proeedings of the 13th World Conference on Non-Destructive Testing, Sao Paulo (Brazil), 18–23 Oct. 1992, Vol. 1, pp. 424–428. Edited by C. Hallai and P. Kulcsar. Elsevier (1992)

Magnetic Barkhausen Noise analysis for the assessment of microstructures in heat treated 2.25CR-1Mo and 17-4-PH steels : 51003 Bhattacharya, D.K.; Vaidyanathan, S.; Moorthy, V.; Jayakumar, T.; Raj, B. Non-Destructive Testing 92. Proeedings of the 13th World Conference on Non-Destructive Testing, Sao Paulo (Brazil), 18–23 Oct. 1992, Vol. 1, pp. 424–428. Edited by C. Hallai and P. Kulcsar. Elsevier (1992)

Characterization of microstructures in 17-4-PH stainless steel by magnetic Barkhausen noise analysis : 54558 Bhattacharya, D.K.; Jayakumar, T.; Moorthy, V.; Vaidyanathan, S.; Raj, B. NDT&E International, Vol. 26, No. 3, pp. 141–148 (Jun. 1993)

Characterization of microstructures in 17-4-PH stainless steel by magnetic Barkhausen noise analysis : 54558 Bhattacharya, D.K.; Jayakumar, T.; Moorthy, V.; Vaidyanathan, S.; Raj, B. NDT&E International, Vol. 26, No. 3, pp. 141–148 (Jun. 1993)

Analoge und digitale Analyse des Barkhausen-Rauschens ım Vergleich

A new technique determining the pulse rate in Barkhausen noise analysis performs superior to the conventional state of the art of evaluating the rectified noise levels. The improvements refer to higher precision and smaller influence of experimental ambiguities.

Nondestructive Evaluation of Navy Structural Components Using Barkhausen Noise Analysis

This paper presents the use of Barkhausen noise analysis (BNA) to nondestructively evaluate residual stresses in (1) shot-peened Almen strips made of 1070 steel, (2) a 4340 landing gear piston, and (3) a D6AC steel bulkhead. BNA output and X-ray stress values were compared and correlated for each of the components mentioned above. Almen strips were compared in the range of Almen intensity 2A-17A. BNA was consistent with X-ray diffraction measurements in the Almen strips and the landing gear piston. Quantitative analysis of stress characteristics between the two techniques was also discussed for the D6AC bulkhead.

Effects of creep damage, shot peening, and case hardening on magnetic Barkhausen noise analysis

The micromagnetic emissions, commonly known as Barkhausen noise, are very sensitive to variations in the microstructure and sub-surface stress states of magnetic materials. Steel pipelines at power plants often have creep damage due to microstructural changes in their service life. Early detection of this damage will prevent costly failures. There is also an increasing demand to characterize the sub-surface stress states in structural materials such as high strength materials used in landing gear components in the aerospace industry. Shot peening is used to improve the fatigue strength of these components by the introduction of residual compressive stresses to the surface. Because the magnitude of Barkhausen noise varies with the magnitude of compressive stress, these noise measurements can be used for in-situ evaluation of the effectiveness of the shot peening process. Furthermore, surface modification such as case hardened magnetic samples can be easily observed using micromagnetic Barkhausen noise (MBE) to determine further modification needs. >

Influence of DC bias field, excitation and detection frequencies on magnetic Barkhausen noise analysis

The micromagnetic Barkhausen emissions, widely known as Barkhausen noise, are quite dependent on excitation and detection frequencies. The input variables to generate these emissions are amplitude, wave form and frequency of magnetic excitation field. When DC bias field is coupled with an AC magnetic field, this complex excitation give rises to distortion of the magnetic hysteresis loop. Recent work showed the frequency dependence of hysteresis curves in ferromagnetic materials. Since there is strong correlation between the location on the B/spl Pi/ loop and Barkhausen noise, comprehending the magnetization mechanisms at each location is essential. The current investigation indicated significant changes in voltage waveforms, pulse height spectra, frequency spectra and RMS voltages of magnetic Barkhausen noise in magnetic materials with different DC bias fields, detection and excitation frequencies. >

Development of a data management system and Barkhausen noise analysis residual stress measurement criteria for freight car wheels: Burkhardt, G.L. Southwest Research Inst., San Antonio, Texas (United States), PB92- 143023/GAR, 86 pp. (Nov. 1991)

Development of a data management system and Barkhausen noise analysis residual stress measurement criteria for freight car wheels: Burkhardt, G.L. Southwest Research Inst., San Antonio, Texas (United States), PB92- 143023/GAR, 86 pp. (Nov. 1991)

Characterization of microstructures in 17-4-PH stainless steel by magnetic Barkhausen noise analysis

Magnetic Barkhausen noise (MBN) signals have been used to characterize the microstructures in quench-aged precipitation hardening 17-4-PH stainless steel. The MBN data have been compared with hardness and coercivity. Microstructures were evaluated by optical, scanning electron and transmission electron microscopy. It was found that MBN signals correlate well with the microstructures manifested by the presence of intra-lath spherical and inter-lath copper-rich non-magnetic precipitates. The presence of coherency strains at the peak hardness regions of the aged specimens could be inferred from the MBN data. MBN signals were found to provide a better criterion for the detection of the maximum in coherency strains than the usual hardness data.

Magnetic Barkhausen noise analysis for studying fatigue damage: Bhattacharya, D.K., Vaidyanathan, S., Rao, K.B., Kalyanasundram, P. and Raj, B. Conf. Fatigue and Fracture in Steel and Concrete Structures, ISFF '91, Madras, India, Dec 1991 Vol 2 (Oxford & IBH Publishing Co. Pvt. Ltd, New Delhi, India, 1991) 1137–1151

Magnetic Barkhausen noise analysis for studying fatigue damage: Bhattacharya, D.K., Vaidyanathan, S., Rao, K.B., Kalyanasundram, P. and Raj, B. Conf. Fatigue and Fracture in Steel and Concrete Structures, ISFF '91, Madras, India, Dec 1991 Vol 2 (Oxford & IBH Publishing Co. Pvt. Ltd, New Delhi, India, 1991) 1137–1151

Material Evaluation of Thick Walled Spheroidal Graphite Cast Iron by Barkhausen Noise Analysis

Material Evaluation of Thick Walled Spheroidal Graphite Cast Iron by Barkhausen Noise Analysis

Non-destructive cooling rate evaluation of 0.4 C-5 CrMoV hot-work tool steel by Barkhausen noise analysis (In Japanese: English abstract) : Tetsu to Hagane (Journal of the Iron and Steel Institute of Japan). Vol. 75, No. 5, pp. 833–840 (May 1989)

Non-destructive cooling rate evaluation of 0.4 C-5 CrMoV hot-work tool steel by Barkhausen noise analysis (In Japanese: English abstract) : Tetsu to Hagane (Journal of the Iron and Steel Institute of Japan). Vol. 75, No. 5, pp. 833–840 (May 1989)

Measurement possibilities of mechanical stress distribution according to depth with Barkhausen-noise analyser : Proceedings of the 9th Congress of Materials Testing, Budapest (Hungary), 29 Sep. – 3 Oct. 1986. Vol. 2. pp. 628–629. Edited by E. Czoboly. Scientific Society of Mechanical Engineers (1986)

Measurement possibilities of mechanical stress distribution according to depth with Barkhausen-noise analyser : Proceedings of the 9th Congress of Materials Testing, Budapest (Hungary), 29 Sep. – 3 Oct. 1986. Vol. 2. pp. 628–629. Edited by E. Czoboly. Scientific Society of Mechanical Engineers (1986)