Accession Number:

AD0843591

Title:

Suppression of Fatigue Cracking Through Control of Surface Conditions.

Descriptive Note:

Final rept. 1 Jun 66-31 May 67,

Corporate Author:

MIDWEST RESEARCH INST KANSAS CITY MO

Personal Author(s):

• Benson, D. K.
• Grosskreutz, J. C.

Report Date:

1968-09-01

Pagination or Media Count:

29.0

Abstract:

Coatings of polyethylene, polyvinylchloride, and evaporated A1 were tested for their effectiveness in suppressing fatigue damage in pure aluminum and 7075-T6 alloy. On pure aluminum, a polymer coating suppresses Stage I fatigue cracking if the coating is applied to a surface possessing a dehydrated oxide. On 7075-T6 alloy, a polymer coating has no effect. These results are discussed in terms of the water vapor effect on the elastic modulus of aluminum oxide and the resulting influence on near-surface dislocations. Author, modified-PL.

Descriptors:

• (*CRACKS
• INHIBITION)
• (*COATINGS
• FATIGUE(MECHANICS))
• (*ALUMINUM ALLOYS
• FATIGUE(MECHANICS))
• ALUMINUM
• CRYSTAL GROWTH
• SURFACE PROPERTIES
• PLASTIC COATINGS
• DISLOCATIONS
• INTERACTIONS
• X RAY PHOTOGRAPHY

Subject Categories:

• Coatings, Colorants and Finishes
• Metallurgy and Metallography
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE