Abstract
Supersaturated solid-solution alloys of Al-Cu systems of up to 8 at%Cu were prepared by means of heat treatments under a pressure of 5.4 GPa and a temperature of 720°C for 10 hours. The elastic constants of the prepared specimens were measured by a three-dimensional resonance method. The Young's modulus E and the shear modulus G of the solid solutions increased with increased concentrations of the Cu atoms in the alloys, and features related to the mean numbers of valence electrons per atom (e/a) were discussed by the free-electron theory. The specimens of the solid solutions were measured step-by-step. The maximum shear modulus was observed during the precipitation of the θ'-phase at 300°C-aging. Temperature coefficients of the moduli of the Al-6 at%Cu specimens were also measured throughout various stages of the treatments.
