H-Field Shielding Effectiveness of Flame-Sprayed and Thin Solid Aluminum and Copper Sheets

Laboratory data are presented for H-field shielding effectiveness of sheets (¿ 20 mil) of aluminum and copper, both in relatively pure form and deposited by flame spraying on insulating material in a normal atmosphere. The measured shielding effectiveness is compared to values calculated on the basis of measured conductivity. The flame-spray conductivity was measured to be much lower than that of the pure metal; the shielding effectiveness of flame-sprayed insulating sheets is correspondingly low and in quantitative accord with the measured conductivity. It is shown that the flame-spray process, at least when performed in normal atmosphere, does not result in good shielding effectiveness to weight ratio.