Silver fusion is a technique created in the Kingfisher Designs studio. Sterling silver is fused to the copper under the torch.
Since the melting temperature of the two metals is really not that different, it is a very delicate balance to get them to actually fuse.
The silver will not flake off or wear off as the silver and copper are actually bonded together. Most silver fusion pieces have a patina so the silver shows up well against the copper background.
Copper cleaner will remove the patina and the contrast between the silver and the copper.