Preparation and Property of Fe-Si-Al Alloy Microwave Absorbing Material

High purity Fe,Si and Al powders were used as raw materials to prepare Fe-Si-Al alloy by mechanical alloying (MA) method.The phase compositions of the alloying products with different milling times and their electromagnetic properties in the range of 1-18 GHz were investigated by means of XRD and vector network analyzer.The results show that Fe-Si-Al alloy can be obtained by MA method,and the complete alloying time was 80 h.The Fe-Si-Al powders had more excellent electromagnetic parameters compared with the raw iron powders.The 3 mm microwave absorber,in which Fe-Si-Al alloy volume fraction was 43% exhibited low reflectivity in 2-4 GHz frequency range.The minimum reflectivity of the specimen was -16 dB at 3 GHz.