Construction of Energy Loops Using Magnetic Barkhausen Noise

Abstract

Magnetic Barkhausen noise (MBN), which contains microstructure information of materials, is widely used in nondestructive testing (NDT) of magnetic materials. MBN energy (MBN _energy ) is a time-independent indicator for NDT, but the initial MBN _energy has no clear physical meaning and cannot be used to explain the relationship to the hysteresis loop. In this letter, based on the physical mechanism of MBN, a proportional relation is built between the MBN voltage signal V _B and energy loss, and the signal V _B is then related to the energy loss through wall pinning in the Jiles–Atherton hysteresis model. We define a novel magnetic Barkhausen noise energy eigenvalue (MBNE ) as the time integral of the product of the absolute value of V _B and the sign function sign( dH / dt ). We prove that the MBNE is proportional to the irreversible magnetization M _irr . Since M _irr is equal to the saturation magnetization M _s when the magnetization of ferromagnetic material reaches saturation, we scaled the MBNE to make its maximum value equal to M _s and found that MBNE with respect to the magnetic field H , MBNE( H ), coincides with the irreversible hysteresis loop M _irr ( H ). We refer to MBNE( H ) as the MBN energy loop. The MBNE( H ) and M _irr ( H ) for two kinds of electrical steel sheets are compared experimentally, which validates the adaptability of the MBNE( H ) construction method. The method to obtain M _irr ( H ) from the MBN raw signal reveals the physical mechanism of MBN and the irreversible magnetization process of magnetic materials.