Acta Metallurgica Sinica (English Letters) ›› 2014, Vol. 27 ›› Issue (5): 918-923.DOI: 10.1007/s40195-014-0145-0

• Orginal Article • Previous Articles     Next Articles

Geomagnetic Shielding Property and Mechanism of Fe-Ni Laminated Composite

Ma Xiangyu1, Zhang Qiang1(), Chen Xiang1,2, Wu Gaohui1()   

  1. (1) School of Material Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China
    (2) Department of Applied Science and Technology, Politecnico di Torino, 10129 Turin, Italy
  • Received:2014-05-30 Revised:2014-08-31 Online:2014-09-30 Published:2014-11-13

Abstract:

Ni layers were deposited on the two sides of pure Fe substrate by using electroplating to form Ni/Fe/Ni diffusion couple. After diffusion heat treatment, Fe-Ni laminated composite was obtained with Fe-Ni alloy/Fe/Fe-Ni alloy structure. The results indicate that the Fe-Ni layers combine well with the substrate and the Fe-Ni/Fe interface presents an interlocking microstructure with small-size grains. The concentration of element Ni in the Fe-Ni layer decreases from surface to interior exhibiting a gradient distribution. Geomagnetic shielding factor (SF) of Fe-Ni laminated composite can reach as high as 22.6, which is about seven times of that of pure Fe substrate. Mathematical equation of SF for laminated structure was derived according to magnetic circuit and resistance theory. The theoretical expression reveals that parameters such as the thickness and magnetic permeability of the shield material play an important role in the magnetic shielding behavior and the theoretical calculation results of SF coincide well with our experimental values.

Key words: Fe-Ni laminated composite, Initial permeability, Magnetic shield, Shielding factor