ISSN:
1573-4889
Keywords:
oxidation in air or oxygen
;
kinetics
;
oxide identification
;
oxygen diffusion
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00603991
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