Magneto-acoustic and Barkhausen emission: Their dependence on dislocations in iron

Buttle, D.J.; Scruby, C. B.; Jakubovics, J. P.; Briggs, G. Andrew D.

doi:10.1080/01418618708214379

Cited by 74 publications

(14 citation statements)

References 11 publications

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“…At the same time it is necessary to improve the area detection algorithm, with a search of independent pulses into an oscilloscope frame. It is widely accepted [17] that MAE and BN signals have different sensibility degrees to changes in magnetic domains derived from the application of external magnetic fields or external mechanical stresses. The stronger MAE signals come from jumps due to wall movements between domains with magnetization 90º apart, and the associated magnetostriction is which promotes the elastic waves emission (MAE).…”

Section: ) No Significant Mae Is Produced During Domain Rotation 4)mentioning

confidence: 99%

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Barkhausen Effect and Acoustic Emission in a Metallic Glass—Preliminary Results

Sánchez¹,

Pumarega²,

Armeite³

et al. 2004

AIP Conference Proceedings

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Section: ) No Significant Mae Is Produced During Domain Rotation 4)mentioning

confidence: 99%

“…In general, MAE signals depend on the same internal conditions as the previously described for BN. In the literature, we can find a variety of important papers on the subject, specially treating crystalline materials, such as those performed by K. Ono [14-15-16] and C. B Scruby [17].…”

Section: Introductionmentioning

confidence: 99%

Barkhausen Effect and Acoustic Emission in a Metallic Glass—Preliminary Results

Sánchez¹,

Pumarega²,

Armeite³

et al. 2004

AIP Conference Proceedings

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“…This emission arises during the magnetization reversal of ferromagnets and is associated with the Barkhausen effect; in structural steels, the MAE is caused primarily by jumps of 90° domain walls [7][8][9][10][11][12].The implementation of the MAE method under actual operational conditions of ferromagnetic ele ments of structures provides the magnetization reversal of a certain volume of a diagnosed object. In this case, the locality and depth of the reversely magnetized region are very important.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Distribution of the induction of a quasi-stationary magnetic field created in a ferromagnet by an attachable electromagnet

Skal’skii

Klim

Pochapskii

2012

Russ J Nondestruct Test

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The magnetoelastic acoustic emission (MAE) method is a promising method for obtaining informa tion on the technical state of a ferromagnetic construction material [1][2][3][4][5][6]. This emission arises during the magnetization reversal of ferromagnets and is associated with the Barkhausen effect; in structural steels, the MAE is caused primarily by jumps of 90° domain walls [7][8][9][10][11][12].The implementation of the MAE method under actual operational conditions of ferromagnetic ele ments of structures provides the magnetization reversal of a certain volume of a diagnosed object. In this case, the locality and depth of the reversely magnetized region are very important. Therefore, calculating the spatiotemporal distribution of the induction of a quasi stationary magnetic field, which is created by an attachable electromagnet (AEM) in a ferromagnetic material, is an important problem. STATE OF INVESTIGATIONSSome results of experimental studies of the distribution of the induction of a stationary magnetic field that is created by an AEM in a ferromagnetic specimen are known from references [13][14][15]. Calculations that were based on the concept of an AEM-ferromagnetic specimen magnetic circuit were also carried out for a stationary case [16][17][18]. Theoretical approaches with consideration for Maxwell's equations ensure the calculation of the distribution of a stationary magnetic field, which is created by electromagnets of different configurations in a ferromagnetic system for several simple particular cases [19][20][21][22]. The results of numerical calculations of the induction of a stationary magnetic field that is created by a U shaped or solenoidal AEM in a ferromagnetic specimen are also known [23,24]. However, as was shown by the analysis of literature sources, data that contain the spatial and time distributions of the induction of a quasi stationary magnetic field that is created by an AEM in a ferromagnetic specimen are virtually absent [25].In our investigations, quasi stationary magnetic fields are considered because, in most cases, MAE is excited by using magnetization reversal frequencies ranging from fractions to units of hertz. Fields at such frequencies include the fields of electrotechnical devices that operate at commercial frequencies.In the quasi stationary electromagnetic approximation, the frequency of changes in the magnetiza tion reversing field is such that the delay effect (radiation effect) and displacement currents can be disre garded [25]. The predominant influence is exerted on electromagnetic processes by conduction currents, which also include eddy currents induced by an alternating magnetic field, in addition to currents from foreign forces that are induced by applied external stresses (as is observed in a stationary case). The value MAGNETIC METHODSAbstract-As a result of numerical calculations, the spatial and time distributions of the induction of a quasi stationary magnetic field, which was created in a studied ferromagnet by U shaped and sole noidal attachable elec...

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“…The MBE technique has proved its viability as a potential NDE technique for microstructural characterization of ferromagnetic 0141± 8610/98 $12.00 Ñ 1998 Taylor & Francis Ltd. materials (Tiitto 1977, Buttle et al 1987b,c, Kameda and Ranjan 1987, Clapham et al 1991, Hill et al 1991, Gatelier-rothea et al 1992, Bhattacharya et al 1993. This phenomenon, called MBE, is attributed to the discrete jumps of domain walls overcoming obstacles and is sensitive to microstructural variation and strain in the material.…”

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confidence: 99%

On the influence of tempered microstructures on magnetic Barkhausen emission in ferritic steels

Jayakuma¹

1998

Philosophical Magazine A

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Magnetic Barkhausen emission (MBE) has been used to characterize various microstructures in tempered 0.2 wt% C steel, 2.25Cr± 1Mo steel and 9Cr± 1Mo steel samples (where the composition is in approximate weight per cent). A twostage process of irreversible magnetic domain wall movement during magnetization is proposed considering the lath or grain boundaries and secondphase precipitates as the two major obstacles to domain-wall movement. The domain walls overcome these two major obstacles over a range of critical ® eld 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 slope changes, appears in the MBE behaviour. On the other hand, if the mean values are widely separated, then two-peak MBE behaviour appears to indicate the in¯uence of these two major obstacles separately. Based on this, the in¯uence of the dissolution of martensite and/or bainite and the precipitation and growth of the second phase precipitates with di erent sizes and morphologies on the MBE has been explained. It is observed that the presence of two or more di erent types of carbide in the Cr± Mo steels signi® cantly reduces the MBE compared with the growth of single carbides in the carbon steel. This study establishes the viability of the MBE technique for identifying di erent stages of tempering in ferritic steels. Figure 7. Optical micrographs of 2.25Cr± 1Mo steel samples tempered at 923 K for (a) 2 h, (b) 10 h, (c) 50 h and (d) 500 h.

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Magneto-acoustic and Barkhausen emission: Their dependence on dislocations in iron

Cited by 74 publications

References 11 publications

Barkhausen Effect and Acoustic Emission in a Metallic Glass—Preliminary Results

Barkhausen Effect and Acoustic Emission in a Metallic Glass—Preliminary Results

Distribution of the induction of a quasi-stationary magnetic field created in a ferromagnet by an attachable electromagnet

On the influence of tempered microstructures on magnetic Barkhausen emission in ferritic steels

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