Brush plated silver is flaking at the edges

A. Hello Ye,
I can't say that I have heard much about heat treatment of silver. Are you sure your under plate is Cu on Ni, and not the other way around? The silver you are brush plating directly on Cu will not hold up very well. The Cu will migrate into the silver layer and you end up with a Cu - Ag inter metallic. A Ni barrier plate is normally used under the silver plate. Anyway, its a good possibility that the first coating of silver wasn't properly cleaned after "heat treatment". The oxide from the heat treatment must all be removed. Did both layers of silver peel? If only the second layer peeled, that would be your answer. Are the Ni and Cu under plate also brush plated? I was also considering if these plated layers were done in a conventional plating bath, there could be some high current density burning which can also cause peeling on the edges of a part. Please let us know what you discover.

A. Ye,
Perhaps the nickel oxidized (dried in the air a bit). Your statement mentions the silver flaking so if the nickel remained there I would suspect oxidation. If the nickel dries or becomes oxidized the silver can flake off later, especially when tested because of a weak bond.