Variations of elastic constants on Al-Si alloys by solid-solutioning under high pressure.

Abstract

Supersaturated solid-solutioning alloys of the Al-Si system up to 15at%Si were prepared by means of high pressure and high temperature techniques. A cylindrical specimen with a size of φ6×6 mm for the solid-solutioning treatment was preserved under the pressure of 5.4 GPa and the temperature of 600°C for 10 hours, and then quenched to room temperature. The elastic constants of thus obtained specimens were measured by a three dimensional resonance method. The Young's modulus E and shear modulus G of the solid solutions were very smaller than that of the two phase alloys, and also were varied to lower values with Si-contents. For example E=77.1 GPa of the two phase Al-10at%Si alloy was fallen to E=62.0 GPa of the solid solution. Density variations of the specimens were also discussed.