Physical mechanism of grain refinement in solidification of undercooled melts
Abstract
It is proposed that the widely observed transitions in solidification of undercooled melts from a coarse grained dendritic to a grain refined equiaxed microstructure result from the fragmentation of dendrites by remelting during the period following recalescence where the inter-dendritic melt solidifies. This mechanism is supported by the experimental demonstration in Cu-Ni alloys that the transition undercoolings vary with cooling rate in a way which is relatively well described quantitatively by a simple fragmentation model. The latter also predicts the occurrence of two transitions, both of which are observed.
- Publication:
-
Physical Review Letters
- Pub Date:
- September 1994
- DOI:
- 10.1103/PhysRevLett.73.1380
- Bibcode:
- 1994PhRvL..73.1380S
- Keywords:
-
- 61.50.Cj;
- 64.70.Dv;
- 68.45.-v;
- Solid-liquid transitions