Effect of annealing temperature on electromagnetic absorption properties of crystalline Fe-Si-Al alloy powder-polymer composites

Abstract

We investigated effect of annealing temperature on lattice strain of crystalline FeSiAl alloy powders and related electromagnetic absorption properties for crystalline FeSiAl alloy powder-polymer composites. The lattice strain of the microforged FeSiAl alloy powder gradually decreased with annealing temperature and highly relieved by annealing treatment at 700 degrees C. The magnetic saturation significantly increased by the microforging and subsequent annealing treatment due to increase of the stress relaxation. The simulated power loss in the near-field regime showed high electromagnetic absorption over 31% in above 1 GHz because of annealing effect. From simulation results of magnetic field distributions in the nearfield, the ferromagnetic metal powder-polymer composite showed excellent electromagnetic absorption in the GHz frequency range. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.