| 초록 |
Al-9.5Si alloys were analyzed via thermomechanical analysis and thermal diffusivity measurement to define the effect of eutectic silicon distribution on the thermal properties. The Al-9.5Si alloys had been manufactured by gravity casting. Levels of eutectic silicon distribution were controlled by solution treatment. The solution treatment was implemented with various holding times (1, 4, 6, 8, 10 h) at 530 °C and then quenched in liquid nitrogen to reduce the natural aging effect. The size of separated eutectic silicon particle was became smaller than as-cast samples proportional with holding time at 530 °C on the scanning electronic microscope analysis. After quenching, solute treated samples were analyzed with thermomechanical analysis to define the changes of coefficient of thermal expansion (CTE). The distributed silicon particles in solution treated samples were promoted the precipitation rate of solved silicon in aluminum matrix during thermomechanical analysis dynamic test. Distribution of eutectic silicon also encouraged the thermal diffusivity of the alloy as long as heat treated at 530 °C. |
