Influence of iron powder content on the electromagnetic and mechanical performance of soft magnetic geopolymer composite

In the induction heating of airport pavement to remove snow and ice, soft magnetic geopolymer composite (SMGC) can be used to gather the dissipated electromagnetic energy, thus enhancing the energy utilization efficiency. The aim of this work is to analyze the influence mechanism of iron powder content on the electromagnetic and mechanical performance of SMGC, so as to provide theoretical guidance for the design of soft magnetic layer within airport pavement structure. The results show that the increase of iron powder content reduces the resistance and magnetoresistance of SMGC by decreasing the content of non-magnetic phases between iron powder. However, the reduction of iron powder spacing also provides a shorter transmission path for the inter-particle eddy currents in the SMGC specimen, which enhances the exchange coupling between iron powder, thus increasing the electromagnetic loss. Therefore, the compatibility between magnetic permeability and electromagnetic loss should be considered comprehensively in the mix design of SMGC. In addition, although iron powder can enhance the mechanical properties of SMGC by improving the density of geopolymer matrix, the excessive amount of iron powder can lead to a weak interfacial transition zone between geopolymer matrix and iron powder. According to the induction heating results, optimized SMGC can improve the energy transfer efficiency of induction heating by 24.03%.