The purpose of this project is to analyze the effects of several chloride rinse agents (CRA’s) on aircraft alloys using electrochemical techniques. This analysis is being carried out in parallel with the “Army Corrosion Retardant Additive Testing” that is being conducted by NASA and Dynacs at the Beach Corrosion Test Site at Kennedy Space Center.

The study analyzes the corrosion behavior of eight different metal alloys (listed in the table) immersed in six different solutions and in demineralized water. The solutions include four commercially available chloride rinse agents along with seawater and 3.5-percent sodium chloride (NaCl). The seawater and the demineralized water are being included as controls. The 3.5-percent NaCl solution was included because it is often used as a substitute for seawater and because of the availability of data on the corrosion behavior of materials in this environment. The commercially available rinse agents are being diluted in accordance with the manufacturers’ specifications.

The study being conducted includes measurement of the opencircuit potential for an hour, linear polarization, potentiodynamic scans (PDS’s), and cyclic polarization scans. The series of experiments is being conducted at different immersion times to monitor the performance of the metal with immersion time. An electrochemical flat cell designed to expose 1 square centimeter of metal to the rinse (electrolyte) is being used in the investigation. The data obtained will be analyzed to determine the corrosion rate, the susceptibility of the metal to pitting corrosion, and the magnitude of recovery.