Effects of energy density on microstructure evolution and electromagnetic interference shielding efficiency of laser cladding Fe84Nb7B9 alloy

To develop Fe-based alloy materials with high electromagnetic shielding properties to meet the demand for the preparation of new electromagnetic shielding materials, Fe84Nb7B9 alloy with high electromagnetic shielding properties was prepared by laser cladding using the elemental powder method. The micro-structure evolution and electromagnetic shielding properties of samples prepared with different laser energy densities were studied. The results show that the energy density has an important impact on the printability and electromagnetic shielding performance of the prepared samples. Under the optimized laser energy density of 119 J/mm2, the Fe84Nb7B9 alloy sample with good printability was successfully prepared and has the highest electromagnetic shielding performance of 87 dB. The mechanism of high electro-magnetic shielding performance of the sample is determined by the synergistic effect of dielectric loss and ohmic loss due to different phase structures, among them, the & DLANGBRAC;-Fe phase mainly promotes dielectric loss, while the "spider web" phase structure composed of & DLANGBRAC;-Fe, NbFeB and Fe2B phase enhances ohmic loss. This study provides a useful reference for the preparation of high electromagnetic shielding Fe-Nb-B alloy by laser cladding. & COPY; 2023 Elsevier B.V. All rights reserved.