Abstract:The Dy-Fe-Co and Dy-Fe-Co-Al alloy powders were prepared by the arc melting method and high energy ball milling. The phase structures and the microstructures of the alloys powders were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), then their microwave absorbing properties were analyzed by Vector network analyzer. The results show that the absorption peaks of DyxFe90-xCo10 (x=6, 9, 12, mole fraction, %) shift towards higher frequency region from lower frequency region. At low frequency, the microwave absorbing properties of Dy6Fe84Co10 alloy is better than those of the others, when the material thickness is 1.8 mm, the absorption peak of Dy6Fe84Co10 alloy reaches –6.7 dB at 3.6 GHz. The addition of Al can improve the low frequency characteristics of Fe-Co alloys. When the thickness is 1.8 mm, the absorption peak of Dy12Fe70Co10Al8 alloy reaches –9.2 dB at 5.4 GHz. The microwave absorbing properties of Dy12Fe70Co10Al8 alloy is better than those of Dy12Fe78Co10 alloy on the band of 3~6 GHz