A NUMERICAL-MODEL FOR SPACING SELECTION OF LAMELLAR EUTECTICS GROWN FROM FLOWING LIQUIDS

A numerical model is established to describe lamellar eutectics grown from the liquid with transverse flow ahead of the liquid/solid interfa ce. The computing results show that the spacing selection for convecti on-free eutectic growth is in good agreement with experimental observa tions. Fluid flow causes the interlamellar spacing to be increased, bu t this structure coarsening effect is strongly dependent on growth rat e. It is also found that flow intensity has an upper limit, below whic h the computation converges, indicating that strong fluid flow is resp onsible for structure instability and morphological transition. (C) 19 98 Elsevier Science B.V. All rights reserved.