scholarly journals Analysis of Magnetic Anisotropy and Non-Homogeneity of S235 Ship Structure Steel after Plastic Straining by the Use of Barkhausen Noise

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4588
Author(s):  
Martin Jurkovič ◽  
Tomáš Kalina ◽  
Katarína Zgútová ◽  
Miroslav Neslušan ◽  
Martin Pitoňák
Keyword(s):  
Magnetic Anisotropy ◽  
Tensile Deformation ◽  
Uniaxial Tensile ◽  
Barkhausen Noise ◽  
Noise Emission ◽  
Ship Structure ◽  
Residual Stress State ◽  
Reliable Monitoring ◽  
The Matrix ◽  
Non Destructive

This study investigates the microstructure, residual stress state, and the corresponding magnetic anisotropy of the ship structure samples made of S235 steel after uniaxial tensile deformation. A non-destructive magnetic technique based on Barkhausen noise is employed for fast and reliable monitoring of samples exposed to the variable degrees of plastic straining. It was found that the progressively developed plastic straining of the matrix results in an alteration of the easy axis of magnetization, stress anisotropy (expressed in residual stresses state) as well as the corresponding Barkhausen noise emission. Moreover, remarkable non-homogeneity can be found within the plastically strained region, especially when the localized plastic straining takes place.

scholarly journals Employment of Barkhausen Noise Technique for Assessment of Prestressing Bars Damage with Respect of Their Over-Stressing

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 770
Author(s):  
František Bahleda ◽  
Ivan Drevený ◽  
Martin Pitoňák ◽  
Miroslav Neslušan ◽  
Peter Koteš
Keyword(s):  
Tensile Stress ◽  
Residual Stresses ◽  
Magnetic Anisotropy ◽  
Perpendicular Direction ◽  
Barkhausen Noise ◽  
Noise Emission ◽  
Steep Increase ◽  
Non Destructive

This paper investigates the potential of a non-destructive magnetic technique based on Barkhausen noise emission for the monitoring of prestressing bars with respect to their undesired over-stressing. Barkhausen noise signals are correlated with tensile stress, residual stresses, and microhardness measurements. It was found that prestressing bars exhibit strong magnetic anisotropy which becomes more pronounced along with the increasing degree of the bar’s over-stressing. Barkhausen noise emission becomes strongly attenuated in the direction of the tensile stress at the expense of the perpendicular direction. However, the Barkhausen noise emission in the direction of the tensile stress exhibits a continuous and remarkable decrease, whereas the Barkhausen noise steep increase for lower degrees of over-stressing is followed by early saturation for higher over-stressing. This study demonstrates that the Barkhausen noise technique is capable of distinguishing between the prestressing bars loaded below yielding, and those which are over-stressed.

Synchrotron x-ray Study of Elastic Phase Strains in the Bulk of an Externally Loaded Cu/Mo Composite

1999 ◽  
Vol 590 ◽  
Author(s):  
A. Wanner ◽  
D.C. Dunand
Keyword(s):  
Plastic Deformation ◽  
Load Transfer ◽  
Tensile Deformation ◽  
Copper Matrix ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Rays ◽  
Synchrotron Source ◽  
Peak Broadening ◽  
The Matrix

ABSTRACTHigh-energy, high-flux x-rays from a third-generation synchrotron source were used to measure average elastic strains in the bulk of 1.5 mm thick composites consisting of a copper matrix reinforced with 7.5 vol.% molybdenum particles. From the evolution of lattice strains in both phases during uniaxial tensile deformation, the internal load transfer between phases and reinforcement damage were characterized during elastic and plastic deformation of the composite. The graininess of the diffraction rings, which is related to the Bragg peak broadening, was quantified as a function of applied stress and related to plastic deformation in the matrix.

scholarly journals Non-Destructive Evaluation of Steel Surfaces after Severe Plastic Deformation via the Barkhausen Noise Technique

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1029 ◽  
Author(s):  
Miroslav Neslušan ◽  
Libor Trško ◽  
Peter Minárik ◽  
Jiří Čapek ◽  
Jozef Bronček ◽  
...  
Keyword(s):  
Shot Peening ◽  
Progressive Increase ◽  
Noise Signal ◽  
Barkhausen Noise ◽  
Noise Emission ◽  
Non Destructive Evaluation ◽  
Almen Intensity ◽  
The Relationship ◽  
Non Destructive ◽  
Severe Shot Peening

This paper reports about the non-destructive evaluation of surfaces after severe shot peening via the Barkhausen noise technique. Residuals stresses and the corresponding Almen intensity, as well as microstructure alterations, are correlated with the Barkhausen noise signal and its extracted features. It was found that residual stresses as well as the Barkhausen noise exhibit a valuable anisotropy. For this reason, the relationship between the Barkhausen noise and stress state is more complicated. On the other hand, the near-the-surface layer exhibits a remarkable deformation induced softening, expressed in terms of the microhardness and the corresponding crystalline size. Such an effect explains the progressive increase of the Barkhausen noise emission along with the shot-peening time. Therefore, the Barkhausen noise can be considered as a promising technique capable of distinguishing between the variable regimes of severe shoot peening.

Recycled HDPE-tetrapack composites. Isothermal crystallization, light scattering and mechanical properties

2012 ◽  
Vol 1485 ◽  
pp. 77-82 ◽  
Author(s):  
A Parada-Soria ◽  
HF Yao ◽  
B Alvarado-Tenorio ◽  
L Sanchez-Cadena ◽  
A Romo-Uribe
Keyword(s):  
Mechanical Properties ◽  
Light Scattering ◽  
Young’S Modulus ◽  
Tensile Deformation ◽  
Young's Modulus ◽  
Ultimate Tensile Stress ◽  
Uniaxial Tensile ◽  
Scanning Calorimetry ◽  
Slow Cooling ◽  
The Matrix

ABSTRACTIn this research the thermal and mechanical properties of composites based on recycled high-density polyethylene (HDPE) and recycled Tetrapak have been investigated. The matrix and filler are recovered from landfills. Multicolor HDPE mixtures, with varying concentration of tetrapack flakes, are hot pressed, as well as single color HDPE flakes. Previous studies determine that the nature of the pigment (organics vs. inorganics) strongly influence the mechanical behavior of multicolor HDPE-tetrapack composites. Thus, this research focuses on single color HDPE hot pressed plaques. The kinetics of crystallization under isothermal conditions is determined by differential scanning calorimetry (DSC). The results show that the crystallization kinetics obeys the Avrami theory, and that the Avrami exponent is 1, irrespective of the pigment in use. Small-angle light scattering is applied to investigate the internal structure of the pigmented HDPE. SALS patterns show that the samples exhibited oriented morphologies. However, after melting and slow cooling under pressure the samples exhibit an isotropic morphology. This is confirmed by polarized optical microscopy. Mechanical properties such as Young’s modulus, yield stress and ultimate tensile stress are obtained under uniaxial tensile deformation at room temperature. For the single color HDPE plaques the Young’s modulus is reduced (after melting), suggesting that the anisotropic molecular chains contribute to the higher value of Young’s modulus.

scholarly journals Asymmetrical Barkhausen Noise of a Hard Milled Surface

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1293 ◽  
Author(s):  
Mária Čilliková ◽  
Anna Mičietová ◽  
Robert Čep ◽  
Branislav Mičieta ◽  
Miroslav Neslušan ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Free Surface ◽  
Sandwich Structure ◽  
Cutting Speed ◽  
Preferential Orientation ◽  
Barkhausen Noise ◽  
Noise Emission ◽  
Hard Milling ◽  
The Matrix ◽  
Milled Surface

This study is focused on the asymmetrical Barkhausen noise emission of a hard milled surface during cyclic magnetisation. The Barkhausen noise is studied as a function of the magnetising voltage and the hard milled surface is compared with a surface after heat treatment. The asymmetry in the Barkhausen noise emission after hard milling occurs due to the typical “sandwich” structure and the different magnetic hardnesses of the different layers beneath the free surface. Furthermore, this asymmetry is also due to the preferential orientation of the matrix in the direction of the cutting speed and magnetostatic fields, which hinder or favour the premagnetising process.

scholarly journals Deep insight on the behaviour of short fibres within a composite under uniaxial tensile

2021 ◽  
Vol 72 (06) ◽  
pp. 659-665
Author(s):  
RIADH ZOUARI ◽  
EMILIA VISILEANU
Keyword(s):  
Textile Industry ◽  
Tensile Deformation ◽  
Mechanical Tests ◽  
Uniaxial Tensile ◽  
Matrix Interface ◽  
Deep Insight ◽  
The Matrix ◽  
Injection Techniques ◽  
Jute Waste ◽  
Mechanical Performances

This work presents an investigation of the mechanical properties of a composite structure manufactured from polypropylene matrix reinforced with jute waste fibres collected from textile industry with extrusion followed by injection techniques. Mechanical tests under uniaxial strain shows that this lightweight vegetal fibre significantly enhanced the mechanical performances of the whole composite with a very slight quantity of compatibilizer which positively influences the final price of the composite. The fracture surfaces showed highly tethered as well as weakly anchored fibres to the matrix. Moreover, in order to have a deep insight on that anchoring behaviour, uniaxial tensile deformation was applied under Scanning Electron Microscopy and evidenced how the fibre/matrix interface plays a high role to strengthen the whole structure. The fibre and matrix interface is not simply resumed to high or weak anchoring but there is a combination of sticking and slipping of reinforcement on the polymeric walls.

scholarly journals Usage of Barkhausen Noise for Assessment of Corrosion Damage on Different Low Alloyed Steels

2021 ◽  
Vol 11 (22) ◽  
pp. 10646
Author(s):  
Filip Pastorek ◽  
Martin Decký ◽  
Miroslav Neslušan ◽  
Martin Pitoňák
Keyword(s):  
Salt Spray ◽  
Corrosion Damage ◽  
Noise Signal ◽  
Peak Position ◽  
Barkhausen Noise ◽  
Variable Degree ◽  
Neutral Salt ◽  
Noise Emission ◽  
Corrosion Attack ◽  
Non Destructive

This study deals with corrosion damage of low alloyed feritic steels of variable strength. Three different steels of nominal yield strength 235, 700 and 1100 MPa were subjected to the variable degree of corrosion attack developed in the corrosion chamber under a neutral salt spray (NSS) atmosphere. The corrosion damage was investigated by the use of conventional metallographic observations when the thickness of corroded layer was quantified. Moreover, non-destructive magnetic technique, based on Barkhausen noise, was also employed. It was found that the rate of corrosion damage decreases along with the increasing number of days in the chamber. The similar evolution can be also found for Barkhausen noise emission and the extracted parameters from the emission. It can be reported that conventional rms value of Barkhausen noise signal as well as FWHM (full width at half maximum of Barkhausen noise envelope) can be linked with the corrosion extent, especially in the early phases of corrosion attack. The PP (peak position of Barkhausen noise envelope) values exhibit poor sensitivity.

Evaluation of Railway Rails with Non-Destructive Techniques

2014 ◽  
Vol 605 ◽  
pp. 641-644
Author(s):  
Anastasia Karahaliou
Keyword(s):  
Stress State ◽  
Barkhausen Noise ◽  
Non Destructive Testing ◽  
Magnetic Barkhausen Noise ◽  
Testing Methods ◽  
Destructive Testing ◽  
Residual Stress State ◽  
Non Destructive ◽  
Non Destructive Techniques ◽  
Scanning Electron

Non-destructive testing methods, such as Magnetic Barkhausen Noise method, are widely used on railways for examining the stress state of running railway rails. Detailed information about the morphology of the microstructure features of the rail surface is derived by Scanning Electron Microscopy. Phase composition, hardness and residual stress state of the rails are determined by MBN signal.

scholarly journals Influence of Components Bending on the Consecutive Plasma Nitridation and Barkhausen Noise Emission

2019 ◽  
Vol 21 (1) ◽  
pp. 22-27
Author(s):  
Miroslav Neslusan ◽  
Jan Moravec
Keyword(s):  
Plasma Nitriding ◽  
Surface States ◽  
Compound Layer ◽  
Barkhausen Noise ◽  
Noise Emission ◽  
Destructive Testing ◽  
Flat Surfaces ◽  
Plasma Nitridation ◽  
Non Destructive Evaluation ◽  
Non Destructive

This paper deals with the non destructive evaluation of components after the plasma nitridation via the Barkhausen noise techniques. Effect of different surface states before the plasma nitriding is studied via the non destructive Barkhausen noise technique, as well as the conventional destructive techniques. Bending of flat samples to different bending angles was performed and magnetic, as well as conventional destructive testing, was carried out on the outer, inner and flat surfaces. The results of experiments show that the Barkhausen noise emission is a function of the heat treatment, whereas intensity of bending and the corresponding deformation are only minor. The different states of the surface before the plasma nitriding result into the similar thickness of the compound layer. Furthermore, the underlying diffusion of near the surface layer state is different.

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