Accession Number:

ADA037156

Title:

Effects of Microstructure on Fatigue Crack Growth of High-Strength Aluminum Alloys.

Descriptive Note:

Final technical rept. May 74-May 76,

Corporate Author:

ALUMINUM CO OF AMERICA ALCOA CENTER PA ALCOA LABS

Personal Author(s):

• Truckner,W. G.
• Staley,J. T.
• Bucci,R. J.
• Thakker,A. B.

Report Date:

1976-08-01

Pagination or Media Count:

276.0

Abstract:

Effects of microstructure and composition on resistance to fatigue crack growth were determined using constant amplitude loading conditions in low and high humidity air at test frequencies of 2 and 20 Hz. Strengthening precipitate had the largest effect at delta K above about 4 KSI sq. root of in., while solute composition had the largest effect at delta K below about 3 KSI sq. root of in.. Large intermetallic particles affected growth at high and intermediate levels of delta K. Author

Descriptors:

• *MICROSTRUCTURE
• *ALUMINUM ALLOYS
• *CRACK PROPAGATION
• *FATIGUE(MECHANICS)
• STRESSES
• FREQUENCY
• LOADS(FORCES)
• TEST METHODS
• HIGH STRENGTH ALLOYS
• FRACTURE(MECHANICS)
• CHEMICAL COMPOSITION
• ENVIRONMENTAL TESTS
• HUMIDITY
• CYCLIC TESTS
• PRECIPITATES

Subject Categories:

• Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE