Composition and non-equilibrium crystallization in partially devitrified co-rich soft magnetic nanocomposite alloys |
| |
| Authors: | PR Ohodnicki YL Qin DE Laughlin ME McHenry M Kodzuka T Ohkubo K Hono MA Willard |
| |
| Affiliation: | 1. Materials Science and Engineering Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA;2. Graduate School of Pure and Applied Sciences, University of Tsukuba, Tenodai 1-1-1, Tsukuba 305-8571, Japan;3. National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Japan;4. Multifunctional Materials Branch, Naval Research Laboratory, Washington, DC 20375, USA |
| |
| Abstract: | The body-centered cubic (bcc) phase tends to preferentially nucleate during solidification of highly undercooled liquid droplets of binary alloy systems, including Fe–Co, Fe–Ni and Fe–Cr–Ni. We investigate a similar tendency during the partial devitrification of Co-rich amorphous precursors of composition (Co1?xFex)88Zr7B4Cu1 by identifying the structure and composition of the nanocrystalline grains. The Co:Fe ratio of the bcc nanocrystals varies linearly with the Co:Fe ratio of the amorphous precursor, and can lie well within the single-phase face-centered cubic (fcc) region of the Fe–Co phase diagram at the crystallization temperature. Classical nucleation theory therefore suggests several potential explanations for the preferential nucleation of bcc phase from an amorphous precursor, including: (i) a reduced amorphous/bcc interface energy as compared to the close-packed phases; (ii) a lower strain of precipitation for bcc nuclei as compared to close-packed fcc and hexagonal close-packed nuclei; and (iii) stabilization of the bcc phase by dissolved glass-formers such as Zr and B. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
