| Two approaches of grain refining related to the use of high-intensity ultrasonic vibration were evaluated. In the first approach, ultrasonic vibration was applied to the molten metal after it was poured into a mold. In the second approach, ultrasonic vibration was used for dispersing SiC nano-particles into molten metal in order to use these particles as nuclei for grain refinement. Experimental results indicate that small grains can be obtained in metal molds using ultrasonic vibration alone. Nano-particles that are dispersed into molten metal using ultrasonic vibration can serve as nuclei for grain refining of Mg alloys. |
