Effect of alloying elements on Nb-rich portion of Nb-Si-X ternary systems and in situ crack observation of Nb-Si-based alloys

Seiji Miura, Toru Hatabata, Takuya Okawa, Tetsuo Mohri

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

To find a new route for microstructure control and to find additive elements beneficial for improving high-temperature strength, a systematic investigation is performed on hypoeutectic Nb-15 at. pct Si-X ternary alloys containing a transition element, Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, Pt, or Au. Information on phase equilibrium is classified in terms of phase stability of silicide phases, α Nb5Si3, Nb4SiX, and Nb3Si, and the relationship between microstructure and mechanical properties both at room temperature and high temperature is investigated. All the additive elements are found to stabilize either α Nb 5Si3 or Nb4SiX but destabilize Nb 3Si. A microstructure of Nbss/α Nb 5Si3 alloy composed of spheroidized α Nb 5Si3 phase embedded in the Nbss matrix is effective for toughening, regardless of the initial as-cast microstructure. Also the plastic deformation of Nbss dendrites may effectively suppress the propagation of longer cracks. High-temperature strength of alloys is governed by the deformation of Nbss phase and increases with higher melting point additives.

Original languageEnglish
Pages (from-to)1136-1147
Number of pages12
JournalMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
Volume45
Issue number3
DOIs
Publication statusPublished - 2014 Mar

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Metals and Alloys

Fingerprint Dive into the research topics of 'Effect of alloying elements on Nb-rich portion of Nb-Si-X ternary systems and in situ crack observation of Nb-Si-based alloys'. Together they form a unique fingerprint.

  • Cite this