Preparation And Microwave Absorbing Properties Of Ce₂Co₁₇ Based Alloy

As one of the effective ways to solve electromagnetic wave pollution,electromagnetic wave absorbing materials pursue high absorption intensity,low matching thickness and wide absorption band at present.In this paper,vacuum smelting,planetary ball milling and other methods were used to prepare the flaky Ce-Co alloy system powders,and the effects of the addition of light rare earth,heavy rare earth and magnetic Ni element on the electromagnetic parameters and microwave absorption properties of the alloy were studied.The minimum reflection loss of the flaky La_xCe_2-x-x Co₁₇?x=0,0.2,0.3,0.4,0.5?alloy powder can reach about-42.29 dB with the addition of 0.4 at the matching thickness of only 1.8 mm,and the effective bandwidth can reach about 2.24 GHz,indicating La_xCe_2-xCo₁₇?x=0,0.2,0.3,0.4,0.5?alloy powders can obtain excellent electromagnetic wave absorption intensity and effective bandwidth in the C-band.In the range of 1.2².4mm,all minimum reflection loss of La_0.4Ce_1.6Co₁₇7 alloy powder less than-18 dB?98.41%absorption rate?,and the effective bandwidth can reach the maximum value of3.52 GHz with the thickness of 1.2 mm.The average particle size of Nd_xCe_2-xCo₁₇?x=0,0.2,0.3,0.4?alloy powder after ball milling increases with the increasing Nd content.The minimum reflection loss value of Nd_0.2Ce_1.8Co₁₇7 alloy powder can receive-42.84 dB at6.88 GHz with the corresponding matching thickness of 2.0 mm,manifesting that Nd_0.2Ce_1.8Co₁₇7 alloy has good absorbing application potential in C-band.The effective bandwidth of the Nd_0.2Ce_1.8Co₁₇7 alloy expanded about 5.8 times with the decrease of thickness ranging from 1.2³.0 mm.In addition,the minimum reflection loss value of Nd_0.4Ce_1.6Co₁₇7 alloy at 3.76 GHz is-24.58 dB,which has a good application prospect in S-band.The average particle size of Dy_xCe_2-xCo₁₇?x=0,0.1,0.2,0.4?alloy powders decreased with increasing Dy content.The minimum reflection loss of Dy_0.2Ce_1.8Co₁₇7 alloy powder can reach-39.16 dB at 8 GHz,and the effective bandwidth of RL<-10 dB is about 2.64GHz.When the matching thickness of Dy_0.2Ce_1.8Co₁₇7 alloy powder reach 1.6 mm,the effective bandwidth can obtain the maximum value of 3.04 GHz,and the minimum reflection loss is as high as-40.28 dB?99.99%absorption rate?.The minimum reflection loss of Dy_0.2Ce_1.8Co₁₇7 powder at 4.88 GHz can reach-12.62 dB?94.53%absorption rate?with the thickness of 2.8 mm in the S-band.The minimum absorption peak frequency of Ho_xCe_2-xCo₁₇?x=0,0.2,0.6,1.0?alloy powders moves to the lower frequency with the increasing Ho content.The minimum reflection loss value of Ho_0.6Ce_1.4Co₁₇7 alloy powder can receive about-42.99 dB?99.99%microwave absorption rate?at 6.48 GHz with the effective bandwidth of 1.6 GHz,indicating the higher absorption intensity can be reached in C band.It can be founded that the minimum reflection loss value at 3.6 GHz is about-12.74 dB?absorption rate can reach 94.68%?by analyzing the microwave absorption property of Ho_0.6Ce_1.4Co₁₇7 alloy powder at different thicknesses.This consequence suggests Ho_0.6Ce_1.4Co₁₇7 alloy can be applied in the S-band.Ce₂Co_17-xNi_x?x=0,0.4,0.8,1.2,1.6?powder is mainly consists of Ce₂Co₁₇7 phase,and the average particle size of the alloy powder gradually increases with the increase of Ni content.The minimum reflection loss value of Ce₂Co_16.6Ni_0.4.4 alloy powder is-30.57 dB at8.32 GHz,and the bandwidth of RL<-10 dB reaches about 2.56 GHz.Besides,the minimum reflection loss value of Ce₂Co_16.6Ni_0.4.4 alloy powder can receive-44.29 dB in the X-band with the thickness of only 1.6 mm.However,the Ce₂Co_15.4Ni_1.6.6 alloy powder has better electromagnetic wave absorption intensity than the Ce₂Co_16.6Ni_0.4.4 alloy powder in the C-band ranging from 2.0 to 2.6 mm.The minimum reflection loss of the Ce₂Co_15.4Ni_1.6alloy at 5.44 GHz is-31.91 dB with the coating thickness of 2.0 mm.The absorption strength of Ce₂Co_16.6Ni_0.4/carbonyl iron powder composite can be enhanced to-38.06 dB at the thickness of 1.8 mm,and the effective bandwidth also can increase from 2.56 GHz to3.68 GHz with the mass ratio of Ce₂Co_16.6Ni_0.4:carbonyl iron powder is 50:50.With the thickness of 1.6 mm,the effective bandwidth can be broadened to 4.64 GHz,and the minimum reflection loss value is about-30.33 dB.