Plating onto Tin Substrate: Smart Nickel Barrier Choice

Summary for plating onto tin substrate Discussion

Plating onto tin substrate is the main concern in this thread, where Mallory Nichols asks whether medallions cast from lead-free solder (mostly tin, sometimes with bismuth) can be plated with copper or gold, and whether an intermediate layer such as nickel or zinc is needed. The response says the process should be possible, but warns that tin and copper or tin and gold may diffuse into each other too readily. The recommended approach is to use nickel plating first as a diffusion barrier, then apply copper or gold on top. The answer also notes that while adhesion problems have been reported when plating onto tin, they are likely less important for medallions that will not be soldered or exposed to high temperatures or significant stress.