Numéro
J. Phys. Colloques
Volume 48, Numéro C3, Septembre 1987
4th International Aluminium Lithium Conference
Page(s) C3-565 - C3-576
DOI https://doi.org/10.1051/jphyscol:1987366
4th International Aluminium Lithium Conference

J. Phys. Colloques 48 (1987) C3-565-C3-576

DOI: 10.1051/jphyscol:1987366

DEPENDENCE OF ELASTIC MODULUS ON MICROSTRUCTURE IN 2090-TYPE ALLOYS

M.E. O' DOWD1, W. RUCH2, E.A. STARKE2 et Jr.2

1  Naval Air Development Center, Warminster, Pennsylvania, U.S.A.
2  Department of Materials Science, University of Virginia, Charlottesville, VA 22901, U.S.A.


Abstract
The Young's modulus, shear modulus and Poisson's ratio were determined using an ultrasonic puise echo technique. Three commercially fabricated aluminum-copper-lithium alloys and an aluminum-lithium binary alloy were examined. The elastic properties were measured as a function of aging time, aging temperature, amount of stretching and testing direction. An increase in Young's modulus due to delta prime and T1 precipitation has been measured and treated quantitatively including precipitation kinetics. A significant decrease of about 5% in the modulus of elasticity was found in the peak age condition. This decrease can be attributed to precipitation of the T2 phase. The shear modulus behaves similar to Young's modulus while the Poisson's ratio remains unchanged. There is no significant orientation dependence of the elastic properties on testing direction despite the fact that a typical. rolling texture was present.