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Fatigue crack propagation in aluminum-lithium alloysThe principal mechanisms which govern the fatigue crack propagation resistance of aluminum-lithium alloys are investigated, with emphasis on their behavior in controlled gaseous and aqueous environments. Extensive data describe the growth kinetics of fatigue cracks in ingot metallurgy Al-Li alloys 2090, 2091, 8090, and 8091 and in powder metallurgy alloys exposed to moist air. Results are compared with data for traditional aluminum alloys 2024, 2124, 2618, 7075, and 7150. Crack growth is found to be dominated by shielding from tortuous crack paths and resultant asperity wedging. Beneficial shielding is minimized for small cracks, for high stress ratios, and for certain loading spectra. While water vapor and aqueous chloride environments enhance crack propagation, Al-Li-Cu alloys behave similarly to 2000-series aluminum alloys. Cracking in water vapor is controlled by hydrogen embrittlement, with surface films having little influence on cyclic plasticity.
Document ID
19910059232
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Rao, K. T. V.
(California Univ. Berkeley. Lawrence Berkeley Lab, CA, United States)
Ritchie, R. O.
(Lawrence Berkeley Laboratory; California, University Berkeley, United States)
Piascik, R. S.
(California Univ. Berkeley. Lawrence Berkeley Lab, CA, United States)
Gangloff, R. P.
(Virginia, University Charlottesville, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1989
Subject Category
Metallic Materials
Meeting Information
Meeting: International Aluminum-Lithium Conference
Location: Williamsburg, VA
Country: United States
Start Date: March 27, 1989
End Date: March 31, 1989
Accession Number
91A43855
Funding Number(s)
CONTRACT_GRANT: DE-AC03-76SF-00098
CONTRACT_GRANT: NAG1-745
Distribution Limits
Public
Copyright
Other

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