Preparation and Properties of Silver-Plated Nickel Powders by Displacement–Reduction Chemical Composite Plating Method with Different Silver Nitrate Concentrations
摘要
To investigate the influence of silver nitrate concentration on the properties of silver-coated nickel (Ag@Ni) powders, silver nitrate was employed as the silver source, with nickel particles serving as the substrate. Ag@Ni powders were synthesized through displacement–reduction chemical composite plating. A conductive coating was prepared using Ag@Ni powders as the filler and unsaturated polyester resin as the matrix, and its conductivity and electromagnetic shielding properties were evaluated. The microstructure and macroscopic characteristics of the Ag@Ni powders were characterized using scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, laser particle size analysis, loose and tapped density measurements, and a DC low-resistance tester. The results indicate that, at a silver nitrate concentration of 50 g/L, the Ag layer on the Ag@Ni powders was complete, uniform, and dense. The loose density of the powders were measured at 5.997 g cm−3, while the tapped density was 5.647 g cm−3. The electrical resistivity of the conductive coating was determined to be 12.77 mΩ cm, and its electromagnetic shielding effectiveness reached 46.83 dB, demonstrating excellent electromagnetic shielding performance.