Abstract
We studied the influence of agitation by ultrasonic vibration on pore formation and growth during the unidirectional solidification of water-carbon dioxide solution. The agitation of liquid affects the pore formation and growth, and the morphology of pores formed during solidification depends on the magnitude of agitation; the agitation of liquid during unidirectional solidification shortens the length of cylindrical pores in lotus metals. This is because the agitation decreases the concentration of carbon dioxide near the solid-liquid interface.