Development of soft magnetic composites for low-loss applications

Abstract Soft magnetic composite materials have been pressed into cylinders using both monotonic and cyclic loading over the pressure range 200–800 MPa. Some samples have subsequently been heat treated over the temperature range 200–600°C. Magnetic Barkhausen noise (MBN) analysis has been used to look at the effects of these various processing stages. Increasing pressing pressure shows an increase in the MBN peak signal. Cyclic pressed samples exhibited larger values of peak MBN signal than the equivalent monotonic load. Subsequent heat treatments decreased the MBN signal. The changes in MBN signal are attributed to the strain-induced changes in domain alignment in the adjacent grains during the pressing process.