Crystallization behavior of Fe70Ni10Cr20 during rapid solidification under different cooling rates

Abstract

Understanding the microstructure during the solidification of alloy is of great significance. In this paper, a molecular dynamics simulation for the rapid cooling of Fe70Ni10Cr20 was conducted at 6 cooling rates within 0.1∼10 K/ps, and the structure was analyzed in terms of the average potential energy, the pair distribution function, the largest standard cluster analysis, and the visualization. It was found that like pure metals, Fe70Ni10Cr20 is extremely difficult to vitrify, but easy cooled into the face-centered cubic (fcc) crystal. A well-mixed alloy liquid can be cooled into solids without significant separation of the three elements. Although energetically unfavorable, a small number of body-centered cubic structures formed at the beginning of phase transition and then decreases rapidly at lower cooling rates. As the screw dislocation in the fcc crystal, the hexagonal close-packed atoms can transfer to fcc ones by slight slides of the close-packed planes; and whether such slides can take place depends on the distribution of fcc crystal regions.