Abstract
New corrosion inhibitors to replace chromate must be discovered and characterized via experimentation. One approach to accelerate the discovery and characterization process is through use of high throughput screening (HTS) methods. This paper presents three methods for rapid screening of potential corrosion inhibitors and identification of their synergistic combinations for aluminum alloy 2024-T3 (AA2024- T3). Methods examined include DC polarization, cyclic voltammetry characterization of surface copper enrichment, and fluorometric detection of Al+3. Tests were conducted on single and binary combinations of the following inhibitors: cerium chloride, yttrium chloride, sodium metatungstate, sodium metavanadate, lanthanum chloride, sodium molybdate, sodium metasilicate, potassium phosphate, sodium phosphate, and barium metaborate. Testing was performed at 3.4 mM total inhibitor concentration in 0.6M NaCl. Testing of the inhibitor combinations revealed both synergistic and antagonistic pairings. Mixtures of rare earth chlorides paired with sodium molybdate rivaled sodium chromate corrosion inhibition using all three HTS methods at pH 7.