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 : SEP 1968

Pagination or Media Count : 29

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