Space environment simulation for material processing by acoustic levitation

Single-axis acoustic levitation of four polymer samples has been realized i n air under the ground-based laboratory conditions for the purpose of space environment simulation of containerless processing. The levitation capabil ities are investigated by numerical calculations based on a model of the bo undary element method corresponding to our levitator and following Gor'kov and Barmatz's method. The calculated results, such as the resonant distance between the reflector and the vibrating source and the positions of levita ted samples, agree well with experimental observation, and the effect of gr avity on the time-averaged potential for levitation force is also revealed. As an application, the containerless melting and solidification of a liqui d crystal, 4-Pentylphenyl-4'-methybenzoate, is successfully accomplished, i ll which undercooling up to 16K is obtained and the rotation and oscillatio n of the sample during solidification may result in fragmentation of the us ual radiating surface growth morphology.