Mechanical and Electromagnetic Shielding Properties of Amorphous FeSiB Ribbon–Reinforced Gypsum Composite Board

Abstract

Gypsum-based composite boards reinforced with mono- and multilayer perforated amorphous Fe78Si9B13 ribbons were fabricated by pouring gypsum slurry directly into molds with prelaid epoxy-resin-coated amorphous ribbons. The influence of structural parameters, including the number of ribbon sequences (n=0, 1, and 2) and the volume fraction (volume%=0%, 0.125%, 0.25%, and 0.375%) and porosity (0%, 2%, 4%, and 6%) of the ribbons on the mechanical and electromagnetic interference (EMI) shielding performance of the composite boards was investigated by experimental testing and numerical simulations. The composite boards exhibited strain hardening accompanied by the formation of multiple cracks during bending. As the number of sequences increased, the cracking strength and ultimate strength of the materials increased from 2.48±0.16 and 2.48±0.16 MPa to 4.70±0.16 to 7.50±0.21 MPa, respectively. The enhanced mechanical properties of the composites were attributed to the epoxy resin coating and the increased porosity supplying good interfacial bond strength between the amorphous ribbons and the matrix; this was favorable to more fracture energy dissipation. Over a frequency range from 30 to 1,500 MHz, the maximum shielding effectiveness (SE) of the composite board reinforced with double-layered ribbons was approximately 80 dB due to the excellent electrical conductivity and soft magnetic property of the amorphous alloy. The electromagnetic interference shielding effectiveness (EMI-SE) and good mechanical properties of the amorphous Fe78Si9B13 ribbon–reinforced gypsum composite indicate its great potential for use as a high-performance structural and functional material. In addition, numerical simulation results of mechanical properties and electromagnetic shielding effectiveness showed that the finite element simulation and experimental test results were in good agreement; the change trend was basically the same. The mechanical simulation agreed well with the experimental results; the relative error for the ultimate flexural capacity was less than 10%. The numerical simulation value for the electromagnetic shielding effectiveness test was basically the same as the experimental test value under various parameters; thus, the numerical simulation may provide a relatively accessible and cost-effective method for the design and optimization of composites.