Abstract
Ag-Zn alloy film specimens prepared by electrodeposition and diffusion annealing were exposed at 303 K and 353 K to N2-O2 atmospheres containing 1 vol% H2S and of 2-90% relative humidity.
Corrosion product layers on the specimens after exposure were investigated using AES, XPS and HEED.
The results were summarized as follows.
(1) It was found that the corrosion product layers on Ag-Zn alloy films containing more than 34.0 mass%Zn mainly consisted of Ag2S, ZnS and ZnO. ZnO and thin ZnSO4 layers were suggested to coexist together.
(2) The corrosion product layer on an electrodeposited Ag-Zn alloy film containing 19.2 mass%Zn mainly consisted of Ag2S and ZnO. ZnO and thin ZnSO4 layers coexisted together in the same way as in alloy films containing more than 34.0 mass% Zn.
(3) CuS whisker was found locally in the corrosion product layers on electrodeposited Ag-Zn alloy films.
(4) HEED patterns indicated the presence of Ag2S, β-ZnS, Ag2SO4, ZnSO4 and ZnO adhering to the Ag-Zn alloy.
