Search results

1

High Resolution Eddy Current Tomography System for Nondestructive Testing

100%

Salach J., Szewczyk R.

|

vol. 126

|

issue 1

402-403

EN

Idea of the high-resolution eddy current tomography is presented. Proposed system gives possibility of testing cylinder-shaped elements made of both magnetic and non-magnetic materials. To validate the concept, the tomographic measurements are carried out on set of steel cylinders with non-magnetic copper inclusion. Measurements were done during both linear and rotational movement of the element. Achieved results indicate the high sensitivity of system, which creates possibility of its application for non-destructive testing of the elements made of ferromagnetic and non-magnetic materials.

2

Non-Destructive Material Homogeneity Evaluation Using Scanning Millimeter Wave Microscopy

100%

Laurinavičius A., Anbinderis T., Ikonikova J., Prishutov Y.

Acta Physica Polonica A

|

2008

|

vol. 113

|

issue 3

1051-1054

EN

Millimeter wave bridge technique for non-destructive material homogeneity characterization is described. The idea of this technique is the local excitation of the millimeter waves in the testing material and the measurement of the transmitted (reflected) wave amplitude and phase in different places of it, i.e. the material plate is scanned by the beam of the millimeter waves. The results of the homogeneity measurements for dielectric wafers according to dielectric constant anisotropy are presented. The measurement technique sensitivity is discussed.

3

Influence of External Factors on Results of Bushing tanδ and Capacitance Measurements

80%

Buchacz J., Szymanski Z.

Acta Physica Polonica A

|

2012

|

vol. 122

|

issue 5

900-904

EN

The paper presents influence of external factors on results of bushing dissipation factor tanδ and capacity measurements performed on not energized transformer as well as with operation voltage using on-line method. There are discussed methods and real cases of measurements, with emphasized differences in results interpretation. Conclusions and literature are summarized.

4

The Response of a Magnetic Fluid to Radio Frequency Electromagnetic Field

70%

Dolník B., Rajňák M., Cimbala R., Kolcunová I., Kurimský J., Balogh J., Džmura J., Petráš J., Kopčanský P., Timko M., Briančin J., Fabián M.

Acta Physica Polonica A

|

2017

|

vol. 131

|

issue 4

946-948

EN

Electromagnetic pollution generated by the electrical devices has been regarded as a new form of pollution, harmful to the society as air and water pollution. The operation of electronic devices in a polluted electromagnetic environment has caused electromagnetic interference to become important concerns. Devices that are vulnerable to interference must often be shielded to protect them from the effects of electromagnetic interference. In this work we describe an interaction of a magnetic fluid based on transformer oil with alternating magnetic field. The magnetic fluid was composed of a transformer oil and dispersed magnetite nanoparticles coated with oleic acid. Among the wide range of topics covered, we pay attention to an important field related to the absorption of electromagnetic field by magnetic fluid as a suitable candidate for applications where it is necessary to electrically isolate, remove excess of heat, and to shield electromagnetic fields. We present a method for the determination of shielding effectiveness of the magnetic fluid under high-frequency excitation conditions from 750 MHz to 3 GHz by means of magnetic near field measurements and analysis. Herein, we report the effect of magnetic volume fraction in the magnetic fluid and the effect of the sample thickness on the shielding effectiveness. We have found that the magnetic fluid has a frequency dependent "windows", characterized that either absorb the magnetic field, or facilitate penetration of the magnetic field through the barrier.

5

Model Materials for Reactor Pressure Vessel

70%

Degmová J., Debarberis L., Kršjak V.

|

issue 5

1054-1056

EN

In this paper we report preliminary results from a study focused on investigation of the role of elements as Cr, Ni, Mn and Si in the radiation stability of reactor pressure vessel steels. Twelve model ferritic steels and eight model welds with basic composition derived from Russian VVER-1000 and Western PWR reactor pressure vessel materials were studied by magnetic Barkhausen noise and Charpy-V impact measurements. Comparison of these two model materials led to the conclusion that the ductile-brittle transition temperatures and Barkhausen noise RMS values of model steels are shifted to the lower values as those of model welds. The VVER-1000 as reference point is shifted to lower RMS values in comparison with model steels and model welds. The next stage of the assessment will involve the investigation of the radiation effect on the model steels with accumulated neutron fluence of 10^{19} n/cm^2.

6

The Shielding Effectiveness of a Magnetic Fluid in Radio Frequency Range

70%

Dolník B., Rajňák M., Cimbala R., Kolcunová I., Kurimský J., Džmura J., Petráš J., Zbojovský J., Kosterec M., Kopčanský P., Timko M.

Acta Physica Polonica A

|

2018

|

vol. 133

|

issue 3

585-587

EN

This article builds on the previous work and describes the interaction of transformer oil-based magnetic fluid (MF) with the radio frequency (RF) magnetic near-field. Three prepared samples of the MF used as a barrier to magnetic near-field, consist of transformer oil and dispersed magnetite nanoparticles coated with oleic acid. We pay attention to the important area related to the electromagnetic field shielding by the MF. Such sample of the MF may be a good candidate for applications where it is necessary to simultaneously electrically isolate, remove the excess of heat and to shield electromagnetic interference (EMI). We present a method for the determination of shielding effectiveness (SE) of the MF under RF excitation conditions ranging from 500 MHz to 3 GHz. We report the effect of magnetic volume fraction in the MF and the effect of the sample thickness on the SE.

7

NDE and SHM of Critical Parts using Magnetic and Electromagnetic Methods

51%

Witoś M., Zieja M., Fallahi N., Żurek Z., Kwaśniewski J.

Acta Physica Polonica A

|

2018

|

vol. 133

|

issue 3

697-700

EN

The paper has been intended to introduce a complex research problem, that is present in aviation, power engineering, mining and transport, with regard to assurance of operational safety for ageing technology, which is exposed to different form of material degradation. Theoretical reasons of non-destructive evaluation (NDE), structural health monitoring (SHM) and active control of material fatigue have been outlined. The magnetic and electromagnetic methods of NDE and SHM such as metal magnetic memory, low frequency eddy current spectroscopy, Barkhausen noise and 3MA have also been presented. The topic has been illustrated by means of practical examples.

8

NDT of Rating Impact of Laser Padding on the Surface Layer

51%

Napadłek W., Witoś M., Prusik T.

Acta Physica Polonica A

|

2018

|

vol. 133

|

issue 3

707-709

EN

The article presents the problem of quality control the paramagnetic material of weld overlays laser made on ferro- and paramagnetic materials (steels, cast iron). To assess the quality of weld overlays paramagnetic material, and also the impact of overheating, besides laboratory researches on Keyence optical microscope, used measurement of existing magnetization of magnetic field distribution. Examples of test results by magnetic memory of metals are presented. It has been found, that is expedient use magnetic methods to assess the quality the microstructure of laser pad welded surface layer (influence of heat generation, microstructure changes, chemical composition and own stresses).

9

Nanocrystallisation of Soft Magnetic Fe-Co-Zr-Cu-B Alloys

51%

Wlazłowska A., Ferenc J., Latuch J., Kulik T.

Acta Physica Polonica A

|

2002

|

vol. 102

|

issue 2

323-328

EN

In the present study, Fe_{41}Co_{41}B_{10}Zr_7Cu_1 alloy has been investigated in order to evaluate its thermal stability and structure after heat treatment, as well as the impact of heat treatment on magnetic properties. X-ray diffractometry, differential scanning calorimetry, chemical composition microanalysis, transmission electron microscopy, and magnetic hysteresis loop measurement techniques were employed. The crystallisation temperature of the as-quenched alloy is 490ºC (continuous heating at 5ºC/min). The melt-spun ribbon having 27μm in thickness was annealed for 1 hour at temperatures from 400 to 700ºC. The alloy after treatment at about 550ºC underwent primary crystallisation, with the average size of crystals under 20 nm. This specimen shows the coercive field of 38 A/m, as compared to about 160 A/m reported for a similar alloy (Fe_{44}Co_{44}B_4Zr_7Cu_1) with a similar structure, annealed at 600ºC.

Refine search results

High Resolution Eddy Current Tomography System for Nondestructive Testing

Non-Destructive Material Homogeneity Evaluation Using Scanning Millimeter Wave Microscopy

Influence of External Factors on Results of Bushing tanδ and Capacitance Measurements

The Response of a Magnetic Fluid to Radio Frequency Electromagnetic Field

Model Materials for Reactor Pressure Vessel

The Shielding Effectiveness of a Magnetic Fluid in Radio Frequency Range

NDE and SHM of Critical Parts using Magnetic and Electromagnetic Methods

NDT of Rating Impact of Laser Padding on the Surface Layer

Nanocrystallisation of Soft Magnetic Fe-Co-Zr-Cu-B Alloys