| With the rapid development of electronics industry and information technology,electromagnetic wave radiation has caused increasing harm to normal life and physical health of human being.Meanwhile,information leakages also affect the precision operation of various types of machinery and equipment,and endanger political,military,and business information security.Therefore,the development of new composite materials suitable for civil engineering structures with electromagnetic shielding effectiveness in different frequency bands,taking into account strength and other architectural functions is of great significant for reducing human health from electromagnetic wave radiation damage,normal operation of machinery and equipment,and protection of various information security.Gypsum board is a kind of architectural material closely related to people's life.It has excellent molding and processing performance,low price,and functions of heat preservation,humidity control and fire prevention.Amorphous alloys,especially industrialized iron-based amorphous alloys,have high strength,strong corrosion resistance,and excellent electromagnetic shielding properties.However,due to the constraints of the preparation process,the product is usually in the form of a thin plate or ribbon of several tens of micrometers,and is currently mainly used in the field of transformers.At present,the output of iron-based amorphous alloys in China is at the forefront of the world,and the production capacity is continuously improving.Therefore,the application of iron-based amorphous alloys is of great significance for the development of China's iron-based amorphous alloy industry.Based on this,in my paper,the preparation process,related mechanical properties and electromagnetic shielding effectiveness of Fe78Si9B13 amorphous alloy-gypsum composite board are studied by combining theory,experiment and numerical simulation,and the structural parameters of Fe78Si9B13 amorphous ribbons are analyzed,including the design of the number of layers,porosity,pore size and the amorphous thin band surface with or without epoxy resin layer,the mechanical properties of the composite board at room temperature and electromagnetic shielding effectiveness.The specific research content is as follows:1.Fe78Si9B13 amorphous alloy-gypsum composite board was prepared in the laboratory;the tensile strength of amorphous ribbon and compressive strength and flexural strength of gypsum were characterized,also the electromagnetic shielding effectiveness of the amorphous alloy was tested.2.The electromagnetic shielding effectiveness,bending strength and ultimate tensile load of the composite board were tested with different structural parameters at room temperature.The effects of structural parameters change on mechanical properties and electromagnetic shielding effectiveness of Fe78Si9B13 amorphous ribbons were analyzed comprehensively.3.Analyze the bending strength of the composite board theoretically,establish the finite element model of 3D nonlinear bending strength simulation of the composite material with the ABAQUS finite element platform,and compare the experimental results by changing the structure parameters of the amorphous alloy to verify the rationality of the model.4.Combining HFSS three-dimensional electromagnetic simulation software,a finite element model for numerical simulation of electromagnetic shielding effectiveness of composite materials was established.Comparing the loss of energy of the flange coaxial model under no-load and load conditions,the structural parameters of the amorphous alloy were compared with experimental test results to verify the rationality of the model.The flexural test results show that the Fe78Si9B13 amorphous alloy-gypsum composite exhibits significant bending strain hardening behavior,and the maximum bending strength is increased by about 336%compared with pure gypsum.With the increase of the number of design layers and open porosity of amorphous alloys,the flexural strength of the alloys increases accordingly,and as the diameter of the amorphous alloy increases,the flexural strength decreases gradually.Amorphous alloy-gypsum pull-out experiments have shown that the pull-out load increases with the increase of the opening ratio of the thin strip.That is,by opening the pores of the amorphous alloy,not only the fluidity of the gypsum slurry is improved,but also the bonding strength and overall workability of the non-gold alloy and the gypsum are enhanced.The coaxial electromagnetic shielding effectiveness test device shows that the composite board exhibits excellent electromagnetic shielding performance in the frequency range of 30MHz-1500MHz,and its SE value is basically stable in the range of 65-105dB.The SE of the composite board weakens with the increase of the opening porosity of the amorphous alloy,and the electromagnetic shielding stability decreases as the thickness of the gypsum layer increases.The finite element numerical simulation results show that the simulation results of bending strength and electromagnetic shielding effectiveness of the composite material are in good agreement with experimental test results.Both models can provide the basis for the structural optimization design of amorphous alloy-gypsum composite panels.Finally,this paper explores the feasibility of a composite design scheme that takes into account mechanical properties and EMI-SE. |
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