Abstract
Change of magnetic properties in direct and alternating fields by forming and sintering condition was studied for the three alloy powders of Fe-12.5Cr, Fe-16Cr and Fe-17Cr-1Mo. The change of different tendency between the relative permeability of direct and alternating fields was observed depending on the condition of forming pressure and sintering temperature. The increase in sintered density occurs with the increase of forming pressure and the rise of sinterig temperature, and the magnetic properties in the direct magnetic field were improved with that. On the contrary, the relative permeability in alternating field indicates a change of increase and then decrease with rise of the sintering temperature. This phenomenon is dependent on the change of the electrical reistivity originated in the porosity in the material. Fe-12.5Cr alloy shows the best magnetic properties in direct and alternating magnetic fields of the three tested alloys. The suitable control of forming and sintering condition as to be 7.0-7.2 g/cm2 in sintered density is important in order to obtain the high magnetic property in alternating field.
