Nucleation of Ni–Fe alloy near the spinodal

✍ Scribed by Y.J. Lü; M. Chen; H. Yang; D.Q. Yu

• Book ID: 103998506
• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 865 KB
• Volume: 56
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.04.025

✦ Synopsis

In molecular dynamics simulations, ''non-classical" nucleation around the spinodal in Fe-Ni alloys is observed by controlling the composition. With increasing Fe concentration, metastable body-centered cubic (bcc) clusters are formed during pre-crystallization under the influence of the spinodal, and then grow into face-centered cubic (fcc)-ordered critical nuclei. When the composition reaches 75 at.% Fe, this transformation is suppressed and the bcc, rather than fcc, symmetry dominates the structure of critical nuclei, a typical nucleation behavior near the spinodal. Further increase in the Fe concentration depresses nucleation below the spinodal temperature. As a consequence, two transient bcc phases characterized by high and low densities appear upon reaching the critical size.