Influence of Mg on the corrosion of Al

Autor: Michael J. Danielson, Mark H. Engelhard, Russell H. Jones, Charles F. Windisch, Donald R. Baer, J.S. Vetrano
Rok vydání: 2000
Předmět:
Zdroj: Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 18:131-136
ISSN: 1520-8559
0734-2101
Popis: This article summarizes a series of experiments to determine the influence of Mg on the corrosion and electrochemical behavior of Al. Magnesium is commonly added to increase the strength of lightweight nonheat treatable Al alloys. However, these alloys are susceptible to grain boundary dissolution, stress corrosion cracking, or hydrogen induced embrittlement due to changes in the alloy structure and elemental distribution during processing, welding, or in-service exposure to elevated temperatures. Auger electron spectroscopy and transmission electron microscopy measurements show that alloys having a distribution of Al3Mg2 (β phase) precipitates and segregated Mg on grain boundaries are more susceptible to cracking. To understand the roles of Mg on the cracking process we compared the corrosion potential and film formation of pure Al, Al implanted with Mg, a 7 wt % Mg–Al alloy and pure Al3Mg2 phase. The surfaces of the specimens were cleaned and prepared in a surface analysis system and transferred in a va...
Databáze: OpenAIRE