Don't you want the lowest on the Noble scale? I wouldn't use aluminum, Charlie.

Anodic index[10][page needed] Metal Index (V)

Most Cathodic
Gold, solid and plated, Gold-platinum alloy -0.00
Rhodium plated on silver-plated copper -0.05
Silver, solid or plated; monel metal. High nickel-copper alloys -0.15
Nickel, solid or plated, titanium an s alloys, Monel -0.30
Copper, solid or plated; low brasses or bronzes; silver solder; German silvery high copper-nickel alloys; nickel-chromium alloys -0.35
Brass and bronzes -0.40
High brasses and bronzes -0.45
18% chromium type corrosion-resistant steels -0.50
Chromium plated; tin plated; 12% chromium type corrosion-resistant steels -0.60
Tin-plate; tin-lead solder -0.65
Lead, solid or plated; high lead alloys -0.70
2000 series wrought aluminum -0.75
Iron, wrought, gray or malleable, plain carbon and low alloy steels -0.85
Aluminum, wrought alloys other than 2000 series aluminum, cast alloys of the silicon type -0.90
Aluminum, cast alloys other than silicon type, cadmium, plated and chromate -0.95
Hot-dip-zinc plate; galvanized steel -1.20
Zinc, wrought; zinc-base die-casting alloys; zinc plated -1.25
Magnesium & magnesium-base alloys, cast or wrought -1.75
Beryllium -1.85