Predicting and understanding vacancy-modified oxygen diffusion in dilute Ni-based alloys by first-principles calculations

Shun Li Shang, Michael C. Gao, Zi-kui Liu

Research output: Contribution to journalArticlepeer-review

Abstract

Controlling oxygen (O) diffusion is critical to materials synthesis, materials degradation, and their oxidation and hot corrosion protection. Herein we investigate O diffusion in dilute Ni-based alloys Ni30VaXO by density functional theory (DFT) based transition state theory using a vacancy (Va) modified mechanism, where X represents 22 alloying elements. The diffusion jump rates are predicted by DFT-based phonon calculations and the quasiharmoinc approach (QHA). It is found that the reactive elements (e.g., Y, Hf, Al, and Cr) that form oxides easily increase O diffusivity while the noble Pt-group elements (e.g., Pt, Pd, Ir, and Rh) that are difficult to oxidize decrease O diffusivity in Ni-based alloys. These results indicate that the bonding strength between X and O, determinable by Ellingham diagram, plays a critical role in affecting O diffusion in Ni. Correlation analysis by means of linear fitting, sequential feature selection, and Shapley value indicates that O diffusivity in Ni30VaXO connects closely to the electronic structures of alloying elements X, such as work function, electronegativity, and valence electrons. In addition, the identified outliers by correlation analysis are mainly alloying elements Y and Mn to correlate O diffusion in Ni30VaXO.

Original languageEnglish (US)
Article number120664
JournalActa Materialia
Volume285
DOIs
StatePublished - Feb 15 2025

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

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