Accession Number:

ADA009788

Title:

Film Breakdown and Pitting

Descriptive Note:

Final rept. 1 Sep 1971-31 Dec 1974

Corporate Author:

ILLINOIS UNIV AT URBANA DEPT OF METALLURGY AND MINING ENGINEERING

Personal Author(s):

Report Date:

1975-04-21

Pagination or Media Count:

7.0

Abstract:

Aluminum was studied in sulfuric acid, with chloride to 0.1M, by electron microscopy, polarization and gravimetric methods. Film breakdown and transient pitting occurred in the absence of chloride. Chloride was not found to alter the film its role was to stabilize pit embryo growth. Stable pit nucleation was conceived as requiring a pit embryo persistent enough to produce sufficient chloride enrichment within the pit. The observed absence of a sharp potential threshold for pit nucleation at low chloride levels was consistent with these views.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE