Polarization of Homogeneous Aluminum-Copper Alloys in Aqueous Sulfuric Acid

In recently reported work,^1,2  the authors found extensive nonuniform corrosion of aluminum-copper alloys arising from the inhomogeneous distribution of copper and inoculants during solidification. In attempting to interpret this behavior quantitatively, the authors performed a series of polarization studies in homogeneous alloys in various media inasmuch as such work had not been previously published. The present note deals with binary aluminum alloys containing 0 to 5% copper and a similar series of ternary alloys containing 0.11% titanium to simulate a grain-refining inoculant. The θ-phase intermetallic (Al₂Cu) was also studied.