Directional Solidification of Arrays of Cells and Dendrites in Microgravity

摘要

A quantitative investigation of the evolution of interface morphologies during directional solidification without influence of buoyancy driven melt flow has been realized. This contribution summarizes results of recent experiments carried out under low gravity conditions using bulk samples of different binary alloys. The primary spacings of the cells or dendrites grown in microgravity environment are larger compared with those grown on earth. The space-grown samples show a morphological order close to a regular hexagonal pattern with less defects than on earth. More detailed investigations of the array indicate a significant dynamic, even at statistically steady-state conditions and without influence of melt flow on the interface morphology.