Technology of Electroless Nickel and Electroless Silver on Graphite Powders

Graphite powders were plated a layer of nickel in alkaline electroless nickel plating bath and electroless plated a continuous silver coating after processes of pretreatment,sensitizing and activating.Effect of bath components and operating conditions on electroless nickel plating and electroless silver plating was discussed.Experimental results show that after electroless nickel plating and two times electroless silver plating,graphite powders covered with nickel and silver coatings in greyish white color can be obtained.The powders have small density and have a electric resistivity of 1.5×10(-4)Ω·cm.Silican rubber filling with the powders,an electromagnetic shielding effect of 82 db in low frequency area can be obtained.The powders are a new type of filler with high performances of electric conduction and magnetic conduction.