Inter-diffusion behavior of Ni/Fe/Ni laminated composite for magnetic and electromagnetic interference shielding

For the purpose of broadband shielding application, high permeable magnetic Fe-Ni alloy coatings were produced on the two sides of iron plate to form laminated composite. The thin Ni coatings were deposited on the surface of the iron substrate with electroplating. Then, the inter-diffusion behavior between the Ni thin coating and iron plate occurred in heat treatment process. Good bonding exists between Fe-Ni layer and the iron substrate with an interlocking interface. The Ni elemental content decreases with diffusion temperature increasing and time expansion. The calculation equation of surface Ni concentration is derived on the basis of one-dimensional plate model and Fick's second law. The temperature dependence of the diffusion coefficient has been also determined as a function on the basis of the experimental results of Ni concentration.