Elastic and mechanical properties of Nb(Cr, V)2 C15 Laves phases

D. J. Thoma, F. Chu, P. Peralta, P. G. Kotula, K. C. Chen, T. E. Mitchell

Research output: Contribution to journalArticlepeer-review

40 Scopus citations

Abstract

The effect of vanadium alloying additions to NbCr2 has been studied, focusing on the phase stability, defect structures, elastic properties, and mechanical behavior of these C15 Laves phases. First, the ternary Nb-Cr-V phase diagram is presented. The C15 phase field of NbCr2 is significantly extended by V alloying along the constant niobium isoplethal section, suggesting that V atoms substitute primarily on Cr sites rather than Nb sites. Next, the elastic properties of the CIS Nb(Cr, V)2 Laves phases were examined using resonant ultrasound spectroscopy. The vanadium alloyed Laves phase alloys have slightly higher shear modulus values and lower Poisson's ratios than binary NbCr2. Finally, the mechanical properties of the C15 phases were investigated by indentation tests at different temperatures. Increasing the vanadium content modestly increases the strength but slightly decreases the fracture toughness and increases the brittle-to-ductile transition temperature in the alloys. The correlations between the phase stability, defect structures, elastic properties, and mechanical response of the C15 phases are discussed using a combination of atomic size arguments and electronic structure analyses. From these interpretations, an alloying strategy for improving the mechanical properties in C15 NbCr2 is proposed.

Original languageEnglish (US)
Pages (from-to)251-259
Number of pages9
JournalMaterials Science and Engineering A
Volume239-240
Issue number1-2
DOIs
StatePublished - Dec 1997
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Elastic and mechanical properties of Nb(Cr, V)<sub>2</sub> C15 Laves phases'. Together they form a unique fingerprint.

Cite this