An experiment on Marangoni convection in a liquid column of silicone oil under microgravity was performed using the TR-IA sounding rocket and compared with computer simulations. During the experiment, cross-sectional distributions of aluminum particles in the column were observed .By tracking the paths of the particles, velocity profiles of Marangoni convection were obtained. Experimental results agree with simulated results, demonstrating sufficient experimental resolution.

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Melting and solidification phenomena of polycrystalline YBa2Cu3Ox bulk sample in microgravity were studied by utilizing TR-IA sounding rocket. Microgravitational experiment and the terrestrial one were carried out by using HTF apparatus to improve the fundamental understanding of these phenomena in microgravity. Video image observation reveals that oxygen gas bubbles were released at the liquid surface of the specimen more frequently in the terrestrial than in microgravity. Macroscopically, major difference between both samples is confirmed in the molten region. This can be explained by the difference in the conditions of thermal conduction and heat flow between both environments. No superconductivity is observed in both samples at the “as melt-solidified” state. After the post annealing, the μG sample shows steeper superconducting transition than the terrestrial one.

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Two dispersion alloys of Cu-5vol%Al2O3 and Cu-5vol%W-2mass%Ti were produced by powder metallurgical techniques including a special mixing technique, namely, mechanical grinding. Samples produced were melted and solidified in a μG environment obtained by Rocket experiment. Microstructure of the solidified samples was examined in comparing with that of the samples solidified on the ground. The correlation between micro structural morphology and various factors such as gravity, mechanical grinding, interfacial energies was also investigated.

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CVD (Chemical Vapor Deposition) film synthesis under microgravity environment is interesting, because microgravity greatly influences thermal convection of vapor. However, there are some difficulties for CVD experiments in such a microgravity environment as space. The most serious problem is disposition of exhaust gas. In this paper, diamond thin film was synthesized as a terrestrial feasibility study in a closed CVD apparatus to deal with the above problem. As a result, we found that the size of reaction chamber and reaction time are very important. On the basis of the results, a case study for diamond thin film synthesis in space is examined.

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We are planning to grow a Ge single crystal under microgravity by the TR-1A rocket in 1992. The furnace temperature should be controlled so as to finish the crystal growth in a quite short time interval (about 6 minutes). This study deals with the computer simulation of rapid crystal growth in space to find proper condition for the experiment. The crystal growth process is influenced by various physical phenomena such as heat conduction, natural and Marangoni convections, phase change and radiation from the fuｒｎace. In this study, a 2-dimensional simulation with axial symmetry is carried out, taking into account the radiation field with a specific temperature distribution of the furnace wall.

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We observed the process of solidification of an organic material with interferometry. The microgravity experiment was performed on a sounding rocket using a sophisticated optical apparatus. The results on both the interface and the fluid phenomena were compared with those from the laboratory experiments. We report the effect of gravity on transfer of latent heat and solidification using salol.

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