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THE FATIGUE CRACK GROWTH BEHAVIOR OF THE Al—Cu—Li ALLOY WELDALITE 049
Author(s) -
Blankenship C. P.,
Starke E. A.
Publication year - 1991
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1991.tb00646.x
Subject(s) - materials science , alloy , paris' law , microstructure , crack closure , metallurgy , slip (aerodynamics) , planar , deformation (meteorology) , composite material , fracture mechanics , thermodynamics , physics , computer graphics (images) , computer science
— The microstructure, deformation behavior, and crack growth relationships have been examined for an Al‐5Cu‐1.3Li‐0.4Mg‐0.4Ag‐0.1Zr alloy. TEM of deformed samples revealed that the T3 temper deformed via highly localized planar slip due to the presence of small, coherent precipitates (GP zones and δ') while the T8 temper deformed homogeneously with T 1 as the strengthening phase. Both constant K max and constant R (0.1) fatigue curves were generated for the T3 and T8 tempers in both the T‐L and L‐T orientations. The T3 temper exhibited high closure levels and an apparent intrinsic threshold of 2 MPa m 1/2 . The T8 temper did not exhibit high closure levels, and the intrinsic threshold was determined to be 1.3 MPa m 1/2 . Weldalite‐T3 has a strength comparable to 2024‐T3 but has a higher resistance to fatigue crack growth, whereas Weldalite‐T8 has a much higher strength and a comparable fatigue crack growth resistance to 2024‐T8.