Effects of surface stress on Barkhausen effect emissions: model predictions and comparison with X-ray diffraction studies

The detection of surface stress in materials is becoming increasingly important in failure analysis. In the case of ferromagnetic steels, the Barkhausen effect provides a practical tool for surface stress evaluation. However, one of the drawbacks of the method has been the lack of an underlying model theory for use in computer simulations of these effects. In recent work a model theory has been suggested and calculations of the effects of stress on the Barkhausen signal amplitude have been made. In this paper results are presented on Barkhausen measurements taken from surface modified materials and x-ray diffraction data from the same specimens. These results show a decrease in Barkhausen signal envelope amplitude with compressive stress in the surface of the material