Electromagnetic shielding property of duplex magnesium alloy with laminated structure processed by accumulative roll bonding

To solve the gradually serious electromagnetic pollution problem, more and more electromagnetic shielding alloys are designed because of its higher conductivities and better workability. However, the increasing incident electromagnetic frequency with the more powerful energy enhance the electromagnetic wave penetrates ability and relatively weakens the alloys' shielding properties. Some researches indicate that the shielding material with laminated structure exhibit better shielding property at higher incident electromagnetic frequency. Accordingly, a novel duplex Mg-9Li alloy with laminated structure of 24-1 interfaces of strips for electromagnetic shielding was designed and fabricated by accumulative roll bonding (ARB) up to 4 cycles at ambient temperature. With the analysis of microstructure evolution and bonding mechanism, the relative conductivity and the density of the alloy are decreased from 15.38% to 12.03% and from 100% to 94%, respectively. Such changes are attributed to insulted oxide or contaminant during roll bonding. The shielding effectiveness (SE) of the sheets are increased from 56 dB to 73 dB at 1350 MHz with the increasing of phase interlayers interface through ARB process which can be ascribed to the laminated structure of Mg-Li alloy processed by ARB shielding properties according to shielding mechanism.