Multiparameter magnetomechanical NDE

We present a new approach to microstructural magnetic nondestructive evalua tion (NDE) based on multiparameter measurements of magnetomechanical proper ties, A steel specimen was magnetized with a C-core using a triangular wave form of order I Hz in frequency. Hysteresis loops were obtained for five qu antities: magnetoacoustic emission (MAE) and Barkhausen effect (BE) intensi ties, magnetic flux derivative, external magnetic field strength, and magne tostriction. The ability to extract the magnetic flux second derivative and the derivative of the magnetostriction permitted the investigation of seve ral new interrelationships between MAE and other magnetic properties. Appro ximate coincidences were observed between MAE peak field position and peaks in magnetic flux second derivative and derivative of the magnetostriction. These effects are discussed and reproduced using existing magnetic modelin g of MAE and corresponding modeling of flux density and magnetostriction.