Accession Number:

AD0625454

Title:

FRACTURE TOUGHNESS, FATIGUE-CRACK PROPAGATION AND CORROSION CHARACTERISTICS OF ALUMINUM ALLOY PLATES FOR WING SKINS.

Descriptive Note:

Quarterly rept. 3, Sep-3 Dec 65,

Corporate Author:

ALCOA RESEARCH LABS ALUMINUM CO OF AMERICA NEW KENSINGTON PA

Personal Author(s):

• Nordmark,G. E.
• Lifka,B. W.
• Kaufman,J. G.

Report Date:

1965-12-15

Pagination or Media Count:

43.0

Abstract:

The fracture toughness, fatigue properties and corrosion resistance of 2020-T651, 2024-T851, 2219-T851 and 7001-T75 are being determined. Fracture-toughness tests of 1-in. specimens of the 2020-T651, 2219-T851 and 7001-T75 were completed during the past quarter. The fracture toughness of 2020-T651 is lowest those of 7001-T75 and 2024-T851 are higher but still about 20 per cent below that of 7075-T651 from AF33657-11155. The fracture toughness of 2219-T851 is exceptionally high, equalling or exceeding that of 7075-T7351. Fatigue tests of center-notched specimens of 2020-T651 and 2219-T851 are complete. Cracks initiate in about the same number of cycles for 2219-T851 as for 2024-T851, and slightly sooner than in 2020-T651 and 7075-T651. Cracks propagate more slowly in 2219-T851 and 2020T651 than in some of the other alloys, but 2020-T651 fails at shorter crack lengths. Corrosion tests show that 2020-T651, 2024-T851 and 2219-T851 are highly resistant to exfoliation attack and to stress-corrosion cracking in any direction at stresses up to 75 per cent of the yield strength, similar to the case for 7075-T7351. Author

Descriptors:

• TOUGHNESS
• CORROSION
• AIRCRAFT PANELS
• WINGS
• TABLES(DATA)
• STRESS CORROSION
• BOLTED JOINTS
• ENVIRONMENTS

Subject Categories:

• Aircraft
• Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE