Engineering Transactions, 53, 4, pp. 375–396, 2005
10.24423/engtrans.449.2006

The Effect of Aging on the Microstructure, Precipitation Response, and Fatigue Behaviour in an Al-Li-Cu Alloy

J. Fragomeni
University of Detroit Mercy
United States

R. Wheeler
Force Research Laboratory Metals
United States

K. V. Jata
Force Research Laboratory Metals
United States

The interrelationships between precipitate characteristics and mechanical properties of an Al-Li-Cu alloy was quantified. The microstructure, precipitation response, and fatigue crack growth rates in the Al-Li-Cu alloy AF/C458 were studied following single and duplex aging treatments for varying aging times on specimens that were given a six percent stretch after solution heat treatment. Aging response was studied using hardness and compression yield strength measurements. Quantitative transmission electron microscopy methods were used to characterize average size, volume fraction, number density, and interparticle spacing of strengthening precipitates, $\delta^\prime$ (Al$_3$Li) and T$_1$ (Al$_2$CuLi). Strength and fatigue crack growth rates for select heat treatments were obtained and were related to the precipitate microstructure and yield strength data.
Keywords: Al-Li-Cu; aging; precipitation strengthening; quantitative microscopy; microstructure; fatigue; hardness; TEM
Full Text: PDF
Copyright © Polish Academy of Sciences & Institute of Fundamental Technological Research (IPPT PAN).

References

A.K. HOPKINS, K.V. JATA, and R.J. RIOJA, Isotropic Wrought Aluminum-Lithium Plate Development Technology, [in:] Fifth International Conference on Aluminum Alloys, Grenoble, France, Materials Science Forum, 217–222, 421–426, 1996.

K.V. JATA, A. K. HOPKINS and R.J. RIOJA, The Anisotropy and Texture of Al-Li Alloys [in:] Fifth International Conference on Aluminum Alloys, Grenoble, France, Materials Science Forum, 217–222, 647–652, 1996.

V.K. JAIN, K.V. JATA, R.J. RIOJA, J.T. MORGAN and A. K. HOPKINS, Processing of an Experimental Aluminum-Lithium Alloy for Controlled Microstructure, Journal of Materials Processing Technology, 73, 108–118, 1998.

A. A. CSONTOS and E. A. STARKĘ JR., The Effect of Processing and Microstructure Development on the Slip and Fracture Behaviour of the 2.1 Wt Pct Li AF/C-489 and 1.8 Wt Pct Li AF/C-458 Al-Li-Cu-X Alloys, Metallurgical and Materials Transactions A, 31A, 1965–1976, 2000.

A.A. CSONTOS, Microstructural effects on the slip and fracture behaviour of isotropic Al-Li-Cu-X alloys, Ph.D. Thesis, 1–205, University of Virginia, 2001.

Aluminum-Lithium Alloys, Bass-Lake Workshop Report, August 18, 1998, Bass Lake Lodge, Wright-Patterson Air Force Base, Ohio, organized/edited by K.V. Jata, Materials Directorate, WPAFB, 1–238, 1998.

D. MATHUR, Localized corrosion and stress corrosion cracking studies of Al-Li-Cu alloy AF/C-458, M.S. Thesis, Ohio State University, 1–190, 2000.

J.E. KERTZ, P.I. GOUMA and R.G. BUCHHEIT, Localized Corrosion Susceptibility of Al-Li-Cu-Mg-Zn Alloy AF/CĄ58 due to Interrupted Quenching from Solutionizing Temperatures, Metallurgical and Materials Transactions A., 32A, 10, 2561–2573A, 2001.

V.K. JAIN, K.V. JATA, R.J. RIOJA, J.T. MORGAN and A.K. HOPKINS, Processing of an Experimental Aluminum-Lithium Alloy for Controlled Micro structure, Journal of Materials Processing Technology, 73, 108–118, 1998.

W. CASSADA, Heterogeneous Precipitation in Al-Li-Cu Alloys, Ph.D. Thesis, University of Virginia, 1–187, 1987.

C.P. BLANKENSHIP, Optimizing Mechanical Properties in Al-Li-X Alloys by Microstructural Design, Ph.D. Thesis, University of Virginia, 4–129, 1992.

M. TAMURA, T. MORI and T. NAKAMURA, Precipitation of Al$_3$Li from an Al-3.0wt. %Li Alloy and Some Properties of Al$_3$Li, Journal Japanese Institute of Metals, 34, 919–925, 1970.

J.C. HUANG, and A. J. ARDELL, Precipitation of Al$_3$Li from an Al-3.0wt. %Li Alloy and Some Properties of Al$_3$Li, Journal De Physique, 48, C3, 373–383, September 1987.

C.P. BLANKENSHIP JR. and E.A. STARKĘ JR., Mechanical Behaviour of Double-Aged AA8090, Metallurgical Transactions A, 24A, 833–841, 1993.

J.F. NIE, B.C. MUDDLE, and L J. POLMEAR, The Effect of Precipitate Shape and Orientation on Dispersion Strengthening in High Strength Aluminum Alloys, Material Science Forum, 217–222, 1257–1262, 1996.

B.M. GABLE, A. A. CSONTOS, and E. A. STARKĘ, JR., The Role of Mechanical Stretch on the Processing–Microstructure–Property Relationships of AF/C 458, Materials Science Forum, 331–337, 1341–1346, 2000.

W. A. CASSADA, G. J. SHIFLET and E. A. STARKĘ, JR., The Effect of Plastic Deformation on Ti Precipitation, Journal De Physique, 48, C3, 397–406, September 1987.

C.P. BLANKENSHIP JR., E. HORNBOGEN and E.A. STARKĘ JR., Predicting Slip Behaviour in Alloys Containing Shearable and Strong Particles, Materials Science and Engineering, A169, 33–41, 1993.

C.P. BLANKENSHIP JR, and E.A. STARKĘ JR, Structure-Property Relationships in Al-Li-Cu-Mg-Ag-Zr Alloy X2095, Acta Metallurgical Materialia, 42, 3, 845–855, 1994.

H.K. HARDY and J.M. SILCOCK The Phase Sections at 500 C and 350 C of Aluminium-Rich Aluminum-Copper-Lithium Alloys, Journal Institute of Metals, 84, 423, 1955–1956.

B. NOBLE and G.E. THOMPSON, Precipitation Characteristics of Aluminium-Lithium Alloys, Metal Science Journal, 5, 357–364, 1971.

Z.X. Li, R.A. MIRSHAMS, E.A. KENIK and P.J. HARTLEY, Effect of Stretch Prior to Aging on Mechanical Properties in Al-Cu-Li, 2195, Alloy, Light Weight Alloys for Aerospace Applications IV, E.W. LEE, W.E. FRAZIER, N. J. KIM, and K. JATA [Eds.], The Minerals, Metals and Materials Society, 117–127, 1997.

J.M. SILCOCK, The Structural Aging Characteristics of Aluminium-Lithium-Copper Alloys, Journal Institute of Metals, 88, 357–364, 1959–60.

M.F. ASHBY and R. EBELING, On the Determination of the Number, Size, Spacing, and Volume Fraction of Spherical Second-Phase Particles from Extraction Replicas, Transactions of the Metallurgical Society of AIME, 236, 1396–1404, 1966.

W.D. JONES and P.P. DAS The Solubility of Li in Al, Journal Institute of Metals, 87, 338–340, 1959.

D.B. WILLIAMS and J.W. EDINGTON, The Precipitation of &'(Al3Li) in Dilute Aluminium-Lithium Alloys, Metal Science Journal, 9, 529–532, 1975.

S.F. BAUMANN and D.B. WILLIAMS, A New Method for the determination of the Precipitate-Matrix Interfacial Energy, Scripta Metallurgica, 18, 611–618, 1984.

P.L. MAKIN and B. RALPH On the Aging of Aluminum-Lithium-Zirconium Alloy, Journal of Materials Science, 19, 3835–3843, 1984.

F.W. GAYLE and J.B. YANDER SANDE, Composite Precipitates in an Al-Li-Zr Alloy, Scripta Metallurgica, 18, 473–478, 1984.

E.E. UNDERWOOD Quantitative Stereology, Addison-Wesley Publishing Company, Reading, Massachusetts, 1–175, 1970.

J.E. HILLIARD, The Counting and Sizing of Particles in Transmission Microscopy, Transactions of the Metallurgical Society of AIME, 224, 906–917, 1962.

E. HORNBOGEN and K.-H. ZUM GAHR, Microstructure and Fatigue Crack Growth in a 7- Fe-Ni-Al Alloy, Acta Metallurgica, 24, 581–592, 1976.

K.V. JATA and E.A. STARKE, Fatigue Crack Growth and Fracture Toughness Behaviour of an Al-Li-Cu Alloy, Metallurgical Transactions, 17A, 1011–1026, 1986.

A.K. VASUDEVAN, K. SADANANDA, Classification of Fatigue Crack Growth Behaviour, Metallurgical and Materials Transactions, 26A, 5, 1221–1234, 1995.

C. W. CORTI, P. COTTERILL and G. A. FITZPATRICK, The Evaluation of the Interparticle Spacing in Dispersion Alloys, International Metallurgical Reviews, The Metals Society, 19, 77–88, 1974.

P.L. GOLDSMITH, The Calculation of True Particle Size Distributions From the Size Observed in a Thin Slice, British Journal of Applied Physics, 18, 81–3–830, 1967.

J.M.G. CROMPTON, R.M. WAGNHORNE and G.B.BROOK, The Estimation of Size Distribution and Density Precipitates From Electron Micrographs of Thin Foils, British Journal of Applied Physics, 17, 1301–1305, 1966.

D.B. WILLIAMS and J.W. EDINGTON, The Precipitation 6'(Al3Li) of in Dilute Aluminum-Lithium Alloys, Metal Science, 9, 529–532, 1975.

G. THOMAS and J. NUTTING, The Ageing Characteristics of Aluminum Alloys, Journal of the Institute of Metals, 88, 81–90, 1959–60.

P.L. MAKIN, and B. RALPH, On the Ageing of an Aluminum-Lithum-Zirconium Alloy, Journal of Material Science, 19, 3835–3843, 1984.

L. CHEN, and Y. WANG, The Continuum Field Approach to Modelling Microstructural Evolution, Journal of Metals, 48, 12 12–18, 1996.




DOI: 10.24423/engtrans.449.2006