Oxidation of Metals

, Volume 14, Issue 2, pp 147–165 | Cite as

High-temperature oxidation of Ti-4.32 wt.% Nb alloy

  • Y. S. Chen
  • C. J. Rosa
Article

Abstract

The oxidation kinetics of Ti-4.32 wt.% Nb (2.27 at.%) alloy in either air or oxygen under 1 bar pressure have been investigated in the temperature range of 1255–1471 K. For oxidation in oxygen the kinetics follow consecutively decreasing parabolic rate laws. The kinetics become nonparabolic after prolonged oxidation in air. X-ray data reveal the presence of TiO2 (rutile) as the main oxide. The presence of Ti2O, δ-TiN, and ɛ-TiN is found on the metal surface after oxidation in air. Microhardness and electron microprobe measurements are used to determine Ti, Nb, O, and N profiles across the oxidized alloy. The oxygen diffusion coefficient in the alloy can be expressed byD=65.6 exp(−234.3/RT) with the activation energy in kilojoules per mole. The oxidation behavior of the alloy is explained.

Key words

oxidation in air or oxygen kinetics oxide identification oxygen diffusion 

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Copyright information

© Plenum Publishing Corporation 1980

Authors and Affiliations

  • Y. S. Chen
    • 1
  • C. J. Rosa
    • 1
  1. 1.Department of Materials Science and Metallurgical EngineeringUniversity of CincinnatiCincinnati

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