The Evolution of Microstructure and Electromagnetic Interference Shielding Effectiveness of Mg-2Mn-1Ce Alloy Prepared by Accumulative Roll Bonding Process

The high electromagnetic interference (EMI) shielding effectiveness (SE) of magnesium alloy was designed and achieved by accumulative roll bonding (ARB) process. The microstructure and the electromagnetic shielding performance of Mg-2Mn-1Ce (ME21) alloy were characterized systematically. A model was put forth to illustrate the EMI shielding mechanisms of ARB-processed sheets. The results indicated that the grain refinement occurred in the initial ARB stages and the homogeneity of the matrix was also ameliorated in the subsequent process. The intensity of basal texture decreased firstly and then reinforced with the augment of ARB cycles as a result of the synergism of dynamic recrystallization mechanism and the severe plastic deformation (SPD) process. Followed by five cycles of ARB process, the average SE reached 101.06 dB and the stability of SE was strengthened, which was resulted from both the improvement of reflection effectiveness and multiple internal reflection. As suggested by these results, ME21 alloy laminate sheets prepared by ARB process were one of the promising materials for EMI shielding application in the X-band (8.2-12.4 GHz) frequency ranges.