TY - EJOU AU - Amberg, Gustav AU - Shiomi, Junichiro TI - Thermocapillary Flow and Phase Change in Some Widespread Materials Processes T2 - Fluid Dynamics \& Materials Processing PY - 2005 VL - 1 IS - 1 SN - 1555-2578 AB - A few issues in materials science are reviewed with regard to the importance of fluid flows. The effect of convection on generic solidification problems is discussed. One relevant class of flows in melts is those driven by surface tension gradients. In welding this thermo- or solutocapillary flow will determine the penetration depth, and will depend very sensitively on the composition of the material, through the dependence of surface tension on temperature, presence of surfactants, etc. In crystal growth the convective motion in the melt may cause instabilities that are often undesired in practical processes. The unsteady flow structure can cause inhomogeneous chemical composition at the solidification interface. Work has recently been done to apply active feedback control to suppress the thermocapillary oscillation. In the high Prandtl limit, a significant attenuation can be obtained by means of rather simple control methods. KW - Thermocapillary KW - convection KW - float zone KW - control KW - welding KW - dendrite DO - 10.3970/fdmp.2005.001.081