Effect of oxygen pressure on the oxidation behavior of NiCoCr medium-entropy alloy at 800 °C

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • W. Kai
  • H. C. Lin
  • F. P. Cheng
  • H. H. Hsieh

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Detail(s)

Original languageEnglish
Article number109411
Journal / PublicationCorrosion Science
Volume185
Online published19 Mar 2021
Publication statusPublished - Jun 2021

Abstract

The oxidation behavior of NiCoCr medium-entropy alloy was investigated at 800 °C in various oxygen pressures from 10 to 105 Pa. The results showed that the oxidation kinetics of NiCoCr followed the parabolic rate law, regardless of oxygen pressure. The oxidation rate constants of the alloy steadily increased with increasing oxygen pressure. The oxidation mechanism of the MEA was mainly controlled by outward cation diffusion to form an exclusive Cr2O3 layer although minor amounts of Co- or Ni-Cr spinels were observed at PO2 = 105 Pa under TEM analyses. The main diffusing species were doubly- and triply-ionized cation vacancies.

Research Area(s)

  • A. Medium-entropy alloy, B. SEM, C. Scales, TEM