A relook at the preferred growth direction of the solid–liquid interface during solidification of pure metals

✍ Scribed by C. Chattopadhyay; S. Sangal; K. Mondal

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 1023 KB
• Volume: 58
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2010.06.009

✦ Synopsis

A simple model for the prediction of the principal growth direction of a solid-liquid interface during solidification of pure metals of different crystal structures is developed. The existing interface controlled growth model for the growth of a solid in a liquid is suitably modified with the incorporation of density change during solidification. The idea of conjugate planes is introduced to construct virtually a unit cell of a solid and, finally, the growth of the conjugate planes is presented with respect to the plane normal. A very good match is shown between the calculated directions of highest growth rate and the experimentally found directions of the primary dendrites of a number of crystal structures. It is also shown that the differential growth of a solid in a liquid along different crystallographic directions is inherently associated with the density change and spatial distribution of atoms on the facing liquid and solid planes on solidification.