Enhanced Electromagnetic Interference Shielding Effectiveness of an Eco-Friendly Cenosphere-Filled Aluminum Matrix Syntactic Foam

Electromagnetic interference (EMI) cause the equipments used in electronics and avionics industries to either deteriorate or malfunction. Therefore, EMI shielding is essential to ensure electronics equipment safety. The present investigation explores the EMI shielding effectiveness of micro-size cenosphere (2 wt.%, 4 wt.%, and 6 wt.%) filled aluminum matrix syntactic foams. The aluminum matrix syntactic foams were fabricated using stir-casting. The prepared samples were studied for their EMI shielding, microstructural characterization, compressive deformation behavior, and hardness. The cenosphere-filled aluminum syntactic foam exhibited better EMI shielding effectiveness, varied from -41.38 dB to -56.68 dB measured in the frequency range 8 to 12 GHz. This is due to microwave absorption and the dielectric nature of porous cenosphere fillers in the syntactic foam. The highest plateau strength 316.48 MPa and compressive yield strength of 289.53 MPa was achieved in 6 wt% cenosphere-filled syntactic foam. The microstructural study showed the presence of cenospheres in spherical form with homogeneous distribution. The observation shows good bonding between the matrix and cenosphere filler element. The micro-hardness measurement varied from 114 HV to 125.6 HV for the cenosphere filled syntactic foam (up to 4 wt %); further increasing the cenosphere wt% reduced the hardness. The XRD analysis showed the presence of reaction compounds AlSiO2, and Al2SiO5 which enhanced the brittleness in the syntactic foams.

Automated summary

This study investigates the EMI shielding effectiveness of micro-size cenosphere filled aluminum matrix syntactic foams. The results show that the aluminum syntactic foam filled with cenospheres has good EMI shielding effectiveness, high mechanical strength, and a well-distributed microstructure.