Accession Number:

ADA277840

Title:

Durability of Adhesively Bonded Structure

Descriptive Note:

Final rept. Apr 1991-May 1992

Corporate Author:

LTV AEROSPACE AND DEFENSE CO DALLAS TX

Personal Author(s):

Report Date:

1992-08-11

Pagination or Media Count:

80.0

Abstract:

Two adhesives were exposed to marine atmosphere for a 10-year period. The specimens compared durability of phosphoric acid anodize to sodium dichromatesulfuric acid OFPL surface preparations, each primed with a chromated epoxy primer. Double lap shear specimens were exposed with no load and spring loaded to two stress levels to compare combined corrosionstress effects. Nondestructive tests were conducted to determine their capability to show delaminations or the presence of corrosion in the adhesive bond line. Specimens were tested for residual mechanical properties after 5 and 10 years. Both room and elevated temperature testing were accomplished. Elevated temperature testing of exposed specimens showed reduced strength significantly below unexposed elevated temperature strengths. Phosphoric acid anodized specimens with the chromated epoxy primer showed markedly superior strength retention to the chromicsulfuric OFPL etch in static stressed specimen in the marine atmosphere. Wedge opened crack extension tests also differentiated between the less and more durable adhesive bonding processes.

Subject Categories:

  • Inorganic Chemistry
  • Adhesives, Seals and Binders
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE