THE FATIGUE CRACK-GROWTH BEHAVIOR OF THE AL-CU-LI ALLOY WELDALITE 049

被引:38
作者
BLANKENSHIP, CP
STARKE, EA
机构
[1] Department of Materials Science, University of Virginia, Charlottesville, Virginia
关键词
D O I
10.1111/j.1460-2695.1991.tb00646.x
中图分类号
TH [机械、仪表工业];
学科分类号
0802 ;
摘要
Abstract— 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 T1 as the strengthening phase. Both constant Kmax 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 m1/2. The T8 temper did not exhibit high closure levels, and the intrinsic threshold was determined to be 1.3 MPa m1/2. 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. Copyright © 1991, Wiley Blackwell. All rights reserved
引用
收藏
页码:103 / 114
页数:12
相关论文
共 26 条
[1]  
Pickens J.R., Heubaum F.H., Langan T.J., Kramer L.S., Al—(4.5–6.3) Cu‐1.3 Li‐0.4 Ag‐0.4 Mg‐0.14 Zr Alloy Weldalite(tm) 049. Aluminum—Lithium Alloys V, 3, pp. 1397-1414, (1989)
[2]  
Rao K.T.V., Piascik R.S., Gangloff R.P., Ritchie R.O., Fatigue crack propagation in aluminum—lithium alloys, Aluminum—Lithium Alloys V, 2, pp. 955-971, (1989)
[3]  
Coyne E.J., Sanders T.H., Starke E.A., The effect of microstructure and moisture on the low cycle fatigue and fatigue crack propagation of two Al‐Li‐X alloys, Aluminum—Lithium Alloys, pp. 293-305, (1981)
[4]  
Sankaran K.K., Grant N.J., Structure and properties of splat quenched 2024‐aluminum alloy containing lithium additions, Aluminum—Lithium Alloys, pp. 205-227, (1981)
[5]  
O'Dowd M.E., Ruch W., Starke E.A., Dependence of elastic modulus on microstructure in 2090‐type alloys. 4th Int, Aluminum‐Lithium Conference, (1987)
[6]  
Gayle F.W., Heubaum F.H., Pickens J.R., Natural aging and reversion behavior of Al‐Cu‐Li‐Ag‐Mg Alloy Weldalite(tm) 049, 2, pp. 701-710, (1989)
[7]  
Sanders T.H., Starke E.A., The effect of slip distribution on the monotonic and cyclic ductility of Al‐Li binary alloys, Acta metall., 30, pp. 927-939, (1982)
[8]  
Jata K.V., Starke E.A., Fatigue crack growth and fracture toughness behavior of an Al‐Li‐Cu alloy, Metall. Trans., 17 A, pp. 1011-1026, (1986)
[9]  
Sainfort P., Guyot P., Fundamental aspects of hardening in Al‐Li and Al‐Li‐Cu alloys, Aluminum—Lithium Alloys, 3, (1986)
[10]  
Howe J.M., Lee J., Vasudevan A.K., Structure and deformation behavior of T<sub>1</sub> precipitate plates in an Al‐2Li‐lCu alloy, Metall. Trans., 19 A, pp. 2911-2920, (1988)