Features of excitation and detection of magnetoacoustic emission in ferromagnetic objects

The interrelationships of magnetic and magneto acoustic-emission characteristics of heat-treated steels of various chemical composition

“…Thus, magnetoacoustic emission makes it possible to register jumps of domain boundaries not only near the surface, but also in the volume of the material [1,2].…”

“…The MAE signal also depends on the reflection of the elastic vibrations from the boundaries of the ferromagnet and, consequently, the MAE parameters depend on the shape and size of the magnetized object. These features should be reflected in the MAE spectrum, which makes it advisable to use broadband piezoelectric transducers for detection of the MAE instead of the previously used narrow-band [2,3].…”

Non-destructive monitoring of tensile of mild steel samples by magnetic Barkhausen and ultrasonic methods

“…MAE is associated with the generation of acoustic signals as a result of continuous changes in magnetization and change of magnetostriction in separate areas of the material. The MAE parameters are obtained from the whole volume of material [8,9,[11][12][13]. The third method is ultrasonic.…”

“…The detected MBN signal is obtained from depths less than 0.2 mm below the surface, i.e. MBN is a surface technique [9,[11][12][13]. MAE is associated with the generation of acoustic signals as a result of continuous changes in magnetization and change of magnetostriction in separate areas of the material.…”

“…Many research papers concerning the stress effect on non-destructive testing parameters reveal results due to different materials and microstructure as well as NDT parameters [1-10, 11, 12, 15, 16, 33, 34]. The most used methods for stress (residual and applied stress) and structure evaluation are magnetic [1,2,15,16,22,24,35], magnetic Barkhausen Noise (MBN) [18][19][20][21][22][23][24][25], magneto acoustic emission (acoustic Barkhausen noise) (MAE) [9,11,12,13,14] and ultrasonic methods [4, 5, 26-29, 30, 31]. The first two methods and effects are due to abrupt movement of magnetic domain walls during the magnetization of samples.…”