Accession Number : ADA187262

Title :   Corrosion Behavior of Sputter-Deposited Aluminum-Based Alloys Exposed to Chloride Solutions.

Descriptive Note : Annual rept. 1 Jul 86-30 Jun 87,

Corporate Author : MARTIN MARIETTA LABS BALTIMORE MD

Personal Author(s) : Moshier, William C ; Davis, G D ; Cote, G O ; Hough, H F ; Vogelsang, M E

PDF Url : ADA187262

Report Date : 30 Sep 1987

Pagination or Media Count : 42

Abstract : In the second year of the program, the investigation of the passivity of sputter-deposited Al alloys has been extended from A1-Mo and A1-Cr to include A1-Ta, A1-Zr, A1-Si, and A1-Cu. A1-Ta was found to have the greatest effect on the breakdown potential of A1. A1-Mo, A1-Zr, and A1-Cr also substantially impact the breakdown potential, whereas A1-Cu and A1-Si have little or no effect. A more extensive study of the corrosion behavior of Al-Mo and Al-Cr was performed in salt spray and pit initiation tests. Whereas the Al-Cr alloys outperformed the Al-Mo alloys in the salt spray tests, Whereas the Al-Cr alloys outperformed the Al-Mo alloys in the salt spray tests, both alloys were substantially more resistant to attack than pure aluminum. Pit initiation tests showed that the order of the reaction between the alloys and pure Al was identical. However, the time required to initiate a pit was substantially longer for Al-Mo than for Al-Cr or pure Al, indicating that the mechanism by which pits nucleate and grow through the film may be different.

Descriptors :   *ALUMINUM ALLOYS, ALUMINUM, ATTACK, CHROMIUM, CORROSION, DEPOSITION, PASSIVITY, PURITY, RESISTANCE, RESPONSE, SALT SPRAY TESTS, SOLUTIONS(MIXTURES), SPUTTERING, ZIRCONIUM, MOLYBDENUM, SILICON, COPPER, TANTALUM, PITTING, CHLORIDES, DEGRADATION

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE