| Hollow glass beads is a lightweight,smooth surface,hollow,small sphericalparticles, usually used as a composite material filler.The addition of the beads couldreduce the density of the matrix,improve the specific strength and specific stiffness of thematerials.The foam plastic which was made by hollow glass beads and polyurethane arewidely used in aviation and aerospace field. After surface metallization, metal powder andmetal wire would be replaced by these hollow glass beads. As soon as they were filledinto matrix material,the electromagnetic shielding material was made,which provide abroad space for the development and application of the electromagnetic shielding material.In this paper,preparation of electromagnetic shielding composite material wasstudied.Coppered beads whose grain diameter are200μm and silvered beads whose graindiameter are20~30μm were filled into epoxy,then the lightweight electromagneticshielding composite material was made.The shielding effectiveness and mechanicalproperty of the composite material were studied in10%,30%and50%of the volumefraction by changing the beads content.In this test, particle size and beads content were variable, six groups of specimenswere made. In the electromagnetic shielding effectiveness tests,the electromagneticshielding effectiveness of the six groups of specimens were tested by flange coaxial testmethod.It was found that the beads size and the filling ratio greated affectedelectromagnetic shielding effectiveness. In the mechanical property test,the basicmechanical property of each specimen was studied through the tensile, creep and stressrelaxation experiments. It was found that the beads size and the filling ratio also greatedaffected mechanical property of each specimen.At last,the coating thickness and beadswall thickness on the influence of effective elastic modulus were studied throughfinite-element analysis. |
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