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  • King_2019_Nb-Ti-V-Zr_prepublication

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DOI

  • D.J.M. King
    Imperial College London, UK
  • S.T.Y. Cheung
    Imperial College London, UK
  • Samuel A. Humphry-Baker
    Imperial College London, UK
  • C. Parkin
    University of Wisconsin-Madison
  • A. Couet
    University of Wisconsin-Madison
  • M. B. Cortie
    University of Technology, Sydney
  • G. R. Lumpkin
    Australian Nuclear Science and Technology Organisation
  • Simon Middleburgh
  • Alexander J. Knowles
    Imperial College London, UK
High-entropy alloys (HEAs) with high melting points and low thermal neutron cross-section are promising new cladding materials for generation III+ and IV power reactors. In this study a recently developed high throughput computational screening tool Alloy Search and Predict (ASAP) has been used to identify the most likely candidate single-phase HEAs with low thermal neutron cross-section, from over a million four-element equimolar combinations. The selected NbTiVZr HEA was further studied by density functional theory (DFT) for moduli and lattice parameter, and by CALPHAD to predict phase formation with temperature. HEAs of NbTiVZrx (x = 0.5, 1, 2) were produced experimentally, with Zr varied as the dominant cross-section modifier. Contrary to previous experimental work, these HEAs were demonstrated to constitute a single-phase HEA system; a result obtained using a faster cooling rate following annealing at 1200°C. However, the beta (BCC) matrix decomposed following aging at 700°C, into a combination of nano-scale beta, alpha (HCP) and C15 Laves phases.
Original languageEnglish
Pages (from-to)435-446
JournalActa Materialia
Volume166
Early online date8 Jan 2019
DOIs
Publication statusPublished - Mar 2019
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