Pattern formation mechanism of directionally-solidified MoSi2/Mo5Si3 eutectic by phase-field simulation

Chuanqi Zhu, Yuichiro Koizumi, Akihiko Chiba, Koretaka Yuge, Kyosuke Kishida, Haruyuki Inui

Research output: Contribution to journalArticlepeer-review

Abstract

A phase-field study has been conducted to obtain an understanding of the formation mechanism of the script lamellar pattern of MoSi2/Mo5Si3 eutectic composite, which is a promising candidate for high-temperature structural application. The spacing of the lamellar pattern in the simulation results shows good agreement with that of experimental observations and analytical solutions under three growth velocities: 10 mm h−1, 50 mm h−1, and 100 mm h−1. The discontinuity of Mo5Si3 rods, in contrast to the regular eutectic with a continuous pattern, is claimed to be caused by the instability of the solid-liquid interface. In this study, the implementation of Mo5Si3 nucleation over the solid-liquid interface has been proposed and successfully reproduced the characteristic of discontinuity. A highly random and intersected lamellar pattern similar to that observed in the ternary MoSi2/Mo5Si3 eutectic alloyed with 0.1 at% Co has been obtained in simulation owing to the increase in the frequency of nucleation. In addition, it has been demonstrated that the inclination of the Mo5Si3 rod can be reproduced by taking into account the strong relaxation of lattice strain energy, which is generally considered to be negligible in eutectic reaction, as the result of the formation of ledge-terrace structure.

Original languageEnglish
Article number106590
JournalIntermetallics
Volume116
DOIs
Publication statusPublished - 2020 Jan

Keywords

  • Anisotropy
  • Interface instability
  • MoSi/MoSi eutectic
  • Phase-field simulation
  • Script lamellar pattern

ASJC Scopus subject areas

  • Chemistry(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Pattern formation mechanism of directionally-solidified MoSi<sub>2</sub>/Mo<sub>5</sub>Si<sub>3</sub> eutectic by phase-field simulation'. Together they form a unique fingerprint.

Cite this