Preparation Of Electrodeposition FeNi Foil And Its Electromagnetic Shielding Performance

With the rapid development of information technology and electron technology, electromagnetic radiation which follows air pollution, water pollution and noise pollution has become the dangerous pollution to all the society. To decrease the electromagnetic radiation and ensure the reliability of equipments, the electromagnetic shielding materials have been developed in recent years. Fe-Ni alloy is widely applied in low frequency for its excellent magnetic performance. But Fe-Ni alloy is limited by its weight. So the electrodeposited Fe-Ni foils are studied to be applied in electromagnetic shielding to decrease the weight.In charter1, the development of electromagnetic compatibility, the electromagnetic shielding materials and the related theory are introduced. And it is introduced why the electrodeposited Fe-Ni foils are applied in electromagnetic shielding.In charter2, the processing parameters of electrodeposited Fe-Ni alloy are studied. Different composition electrodeposited FeNi foils can be obtained by adjusting the radio of Fe2+:Ni2+in the solution. The influence of electrodeposition processing parameters to the structure of Fe-Ni foils is studied. From the above study, the proper processing parameters of electrodeposition Fe-Ni foil are decided.In charter3, the magnetic properties of different composition electrodeposited Fe-Ni foils are studied. The measurement results indicate that the variation of saturation magnetization, coercivity, and magnetic permeability with composition in foils follows some rules. From the rules, the electrodeposited Fe-Ni foils which process excellent magnetic performance are decided.Because the magnetic permeability and coercivity are sensitive to the structure, these parameters vary with the structure which can be changed through heat treatment. The magnetic properties of the Fe-Ni foils which are electrodeposited on copper matrix vary with the different heat treatments. In charter4, the heat treatment process of electrodeposited Fe-Ni is studied. The magnetic properties of the Fe-Ni foils which are annealed between300℃and900℃are tested by LakeShore7410VSM. Some rules can be learned in the magnetic performance data. The measurement results indicate how to choose the better heat treatment process. In charter5, the electrodeposited Fe-Ni alloy is applied to shield the electromagnetic radiation. The electromagnetic shielding performances of electrodeposited Fe-Ni alloy in the broadband-frequency range of0～1.5GHz are tested. The measurement results indicate that the electromagnetic shielding performances in low frequency are improved. The electromagnetic shielding composite materials which are used in all frequency can be made by electrodeposition FeNi.In charter6, electromagnetic shielding composite materials which are made of copper foil and amorphous foil are studied through Schelkunoff transmission line theory. From the theory and measurement results, the influence of the structure to electromagnetic performance is studied.