Abstract：Using the copper powders as the substrate, the silver nitrate as the silver resource, PVP as the dispersant and 1, 4-butylene glycol as the leveling agent, silver coated copper powders were prepared by in-situ reduction method in ethylene diamine tetraacetic acid (EDTA) -Ag (I) -Cu (II) -H₂O system. The products were systematically characterized by using scanning electron microscopy (SEM) , X-ray diffraction meter (XRD) , optical lens spherical aberration correction field emission transmission electron microscopy (STEM-EDS) , simultaneous thermalanalyzer (TGA) , specific surface and void analyzer (BET) and other instruments. The results show that silver is successfully coated on copper substrate and the thickness of plating layer is about 100～150 nm. Silver coated copper powders are a kind of polyhedron granules with good dispersibility, whose particle size is about 2.5 μm. The TGA test results show that the increase of silver plating layer improves the oxidation resistance of copper powder.

Keywords：in-situ reduction method; ethylene diamine tetraacetic acid（EDTA）-Ag（I）-Cu（II）-H₂O system; silver coated copper powders