Study of forced dendritic growth in supercooled melt

SDS (supercooling directional solidification) experiment was designed to study forced dendritic growth under supercooling conditions. It was found that successful supercooling can be obtained only within the range of 127K-170K. Below 127K, release of solidification latent heat leads to reduction of supercooling degree, which in turn makes it difficult to realize preferential orientation. Above 170K, dendrites may be transformed into spherical crystals. The dendritic structure can be described numerically as follows: (1) length of dendritic structure, about 60% of specimen; (2) growth direction, 〈100〉; (3) primary spacing, 50μm. SDS solidified microstructures can be subdivided into three regions: fine equiaxed region; region of transition from fine equiaxed to columnar; columnar region.