Fabrication of Ag-Bi Alloy Films from an Iodide-Tartrate Bath via Current Pulse Electrodeposition

Abstract

Ag-Bi alloy films containing less than 1 mass% Bi were produced using an iodide-tartrate bath without cyanide ions by electrodeposition. Such films could have applications as electrical connectors in quick chargers intended for electric vehicles. The electrodeposition characteristics of these alloys were studied by electrochemical measurements in conjunction with both direct current (DC) and current pulse (CP) plating. The waveform associated with the CP plating incorporated both low and high current densities. The electrodeposition potential of Bi was found to be more negative than that of Ag and the electrodeposition of Bi on Ag was evidently inhibited compared with that on Bi. Aeration increased the limiting current density during electrodeposition of the Ag-Bi alloys. Alloy specimens having powder morphologies could be electrodeposited using the DC plating process while CP plating generated films. Optimization of the waveform gave Ag-Bi alloy films containing less than 1 mass% Bi and having a maximum hardness of 102 HV.