Modeling microstructural effects on Barkhausen effect signals in surface-modified magnetic materials

The relationships between the Barkhausen effect (BE) model parameters and the microstructure of a series of steel samples with various dislocation densities were examined. The steel samples were obtained from an induction-hardened steel rod at different depths. Results indicate that the BE model parameters are inversely proportional to the pinning coefficient k which characterizes the domain wall pinning strength and is dependent on dislocation density. The domain wall pinning strength was determined by simulating the measured hysteresis loops using the energetic hysteresis model.