Abstract:Fe36Co36B20Nb4Si4 alloy powders were prepared by gas atomization technology. Amorphous Fe36Co36B20Nb4Si4 alloy coatings with thickness of about 0.2-0.3 mm were formed by air plasma-spraying the powders onto the H62 brass substrates and aluminium pipes. The results show that the Fe36Co36B20Nb4Si4 alloy coating is almost completely amorphous, and the hardness of the coating is as high as 1 200 HV. The samples coated with Fe36Co36B20Nb4Si4 coating have good shielding performance for both direct current magnetic field and high frequency electromagnetic field. The shielding efficiency is 25 dB at 800 A/m direct current magnetic field and 80 dB at 300 kHz-1.5 GHz frequency band.