Preparation And Absorbing Properties Of FeSiB-based Powders

FeSiB system alloy powders have the advantages of good thermal stability,high Curie temperature,high saturation magnetization,large permeability,high dielectric constant,strong electromagnetic loss,and can adjust the electromagnetic parameters by adjusting the particle size,which is conducive to impedance matching and broadening the absorption band.It is an important electromagnetic wave absorbing material at present.Firstly,the radar wave absorption properties of Fe95-xSi1B2PxCui.5(x=0.5,2,5 at%)alloy powders and Fe95-xSi1B2P0.5Cu1.5Yx(x=0,0.5,1,2 at%)alloy powders modified by rare earth Y were studied.The results show that the alloy powders of Fe95SiiB2P0.5Cui.5 have good absorbing properties.In the frequency range of 0.3-8.5 GHz,the real parts of permeability(μ’)are 3.84-1.0,the real parts of dielectric constant(ε’)are 37.67-14.81,the tangent value of magnetic and dielectric loss angle(tanδ)is 2.02-1.46,and the interference absorbing thickness of 0.3 GHz is 17.70mm;Adding rare earth Y to Fe95Si1B2P0.5Cu1.5 alloy can effectively increase μ,’.In the 0.3-8.5 GHz band,the μ’ of Fe94.5Si1B2P0.5Cu1.5Y0.5 is 5.40-1.22,which is 50%higher than that of Fe95Si1B2P0.5Cu1.5 alloy powders;By high-energy ball milling process,coating Fe95Si1B2P0.5Cu1.5 alloy powders with graphene can greatly increase the dielectric constant of the powders.In the 0.3-8.5 GHz band,the composite powders with graphene doped amount of 1.0wt%have ε’ of 182.4-18.2 and μ’ of 7.3-1.0.The tangent values of the magnetic and dielectric loss angles are 5.28-8.60.The joint mechanism of loss shows excellent absorption performance.Secondly,the radar wave absorption properties of Fe78-xSi9B13Yx(x=0,0.5,1,2 at%)alloy powders were studied.Alloying Y into FeSiB alloy significantly increases the magnetic loss(tanδm)and dielectric loss(tanδe)of the alloy powders.In the Fe78-xSi9B13Yx alloy,the μ" and tanδm of the Fe76Si13B9Y2 alloy powders at the frequency of 0.3 GHz reached 1.50 and 0.36,respectively,which are 44%and 33%higher than those of the Fe78Si13B9 alloy powders,and the ε’,ε" and tanδe reached 43.59,212.45,and 4.87,respectively,which were 1,24 and 11 times higher than Fe78Si13B9 alloy powders.The interference absorption thickness of Fe76Si13B9Y2 alloy powder at 0.3 GHz is 11.81mm,accounting for only 44%of Fe78Si13B9 alloy powders.