Variations of Elastic Constants on Al-Si Alloys by Solid-solutioning under High Pressure

Abstract

Supersaturated solid-solution 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 φ 6×6 mm for the solid-solutioning treatment was held 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. Young's modulus E and shear modulus G of the solid solutions were quite smaller than those of the two phase alloys, and they had lower values depending on Si-contents. For example, E=77.1 GPa of the two phase Al-10at%Si alloy dropped to E=62.0 GPa of the solid solution. Density variations of the specimens were also discussed.