Yup - it's called galvanic corrosion or a galvanic reaction. You know how most outboard motors have zinc anodes on them? That's so the zinc, much lower on the galvanic scale, will take the corrosion hit and sacrifice itself saving the metals that are higher on the galvanic scale...hence the term "sacrificial anode". Eventually the zinc will corrode away and need to be replaced. Most steel (high pressure) natural gas pipelines take this reaction pretty seriously and are protected with similar system (I used to be a cathodic protection technician for a gas company).

Carbon falls under "graphite" in this list...though the carbon shouldn't be corroding when in contact with aluminum (I suspect that the aluminum corroded and became loose in the hole - the wear caused the opening of the carbon)...the aluminum will corrode quickly when in contact with carbon graphite in the same way the zinc anode does.

Wikipedia has a list of common materials on the galvanic scale...the further apart these materials are from each other on this list, the more severe the corrosive reaction will be. All dissimilar metals will have some sort of galvanic reaction.

http://en.wikipedia.org/wiki/Galvanic_series