Barkhausen-Effect and Eddy Current Testing for the Characterization of the Microstructure and Residual Stress States with Local Resolution
The IZFP has developed a microscope based on micromagnetic and eddy-current techniques. By using miniaturized inductive transducers with some tenths of a µm slit width, speciments are scanned in down to one µm increments. Concering the micromagnetic techniques, the magnetic Barkhausen noise is measured, which is mainly sensitive to microstructure and residual stress states. The applied eddy-current technqiue is sensitive to microscopic defects, local changes in permeability and conductivity.