Aluminum has a lower electronegativity (greater tendency to oxidize) than
copper, so it will sacrifice itself for the copper.

From: "Rob"
Date: 7/12/2004 11:07 AM Eastern Daylight Time
Message-id:

My question for the chemically inclined among you is this...Would copper
act as the sacrificial metal or would the aluminum I am trying to protect
sacrifice itself for the copper?

kleindoc