ELECTROCHEMICAL-BEHAVIOR OF THE T-1 (AL2CULI) INTERMETALLIC COMPOUND AND ITS ROLE IN LOCALIZED CORROSION OF AL-2-PERCENT-LI-3-PERCENT-CU ALLOYS

The T-1(AI(2)CuLi) intermetallic compound was synthesized in bulk form for characterization of its electrochemical behavior in chloride solutions by conventional direct current (DC) techniques. Results indicated T-1 was active with respect to its microstructural suroundings in artificially aged Aluminum Association (AA) 2090 (UNS A92090) (Al 2.1% Li-2.6% Cu) and preferential dissolution of T-1 precipitates strongly influenced localized corrosion behavior of the alloy. Subgrain boundaries in artificially aged AA 2090 were particularly susceptible to localized attack because of high concentrations of T-1. The role of T-1 in preferential subgrain boundary attack in a chloride-free sulfate solution also was investigated.