Study On Microstructure And Properties Of Silver-coated Copper Powders With Rare Earth Addition

The technology, microstructure and properties of the Silver-coated Copper Powders with rare earth addition were studied. The basic and optimum formulation of process of the Silver-coated Copper Powders were designed and tested using perpenpular method. The electrochemical properties and effect of concents on plating rate were measured. The structure and micromo-rphology were observed. The oxidation resistance, corrosion resistance and conductibility of coatings were measured. The effect of different kinds of RE on electrochemical properties and plating rate were studied. The mechanism of action and influence mode on the process, structure and properties of the Silver-coated Copper Powders were discussed in order to obtain the Silver-coated Copper Powders with excellent properties. The results showed that after the RE addition to the bath, the plating rate is increased obviously. In some range, plating rate increases at first, then decreases with the increasing addition of RE. Because of the RE being added to bath, the stability of bath, bonding force of coating and surface quality are improved. The rest potential with Ce joined was shuffled with complexing agent and matrix, and the potential with La joined was the opposite; The plating rate increased and the polarizability of alloy minished while the RE added. The component analysis shows that RE was in the coatings and with the increasing of RE the cladding ratio of Ag in the coatings increases. The surface topography of coatings was affected while RE joined, Ag tend to needle-like growth with Ce, and distribute as flake with La. The oxidation resistance, the corrosion resistance and the resistivity of the Silver-coated Copper Powders improve while RE joined.