Relative Permeability of Iron-Chromium Magnetic Alloys in Alternating Magnetic Field

On the two 13Cr-Fe alloys including 0.8%Si and 2.5%Al which were given attention as a new magnetic alloy for alternating field, the amplitude relative permeability in magnetic field is measured and studied to influence of thickness at ring specimen and electrical resistivity as compared with magnetic soft iron and 1%Si-Fe alloy. The amplitude relative permeability of 0.8Si-13Cr-Fe alloy is superior than those of magnetic soft iron and 1%Si-Fe alloy at ferquency range 5 to 20kHz and that of 2.5Al-13Cr-Fe alloy is higher than the compared alloys at almost all frequencies invesigated, although the FeCr alloys have lower magnetic properties in direct magnetic field. Smaller dependence of amplitude relative permeability in alternating field on the thickness of specimens is observed for the two FeCr magnetic alloys than magnetic soft iron and 1%Si-Fe alloy. These changes are dependent on their electrical resistivity.