Effect of Heat Treatment under Low Oxygen Partial Pressure Atmosphere on Oxidation Resistance of Intermetallic Compound TiAl

AbstractOxidized zirconium alloys can appear as black, white and all gray shades depending on the heat treatment process. The black color results from a high amount of oxygen vacancies in non-stoichiometric zirconia (ZrO2−x) that effectively reduces the band gap of the material. In this work we compare the surface properties of black and white zirconia on ZrNb7 substrate. An oxidation in air at 600 °C for 1 h results in a dark-gray oxide with only a few micro cracks. Oxidation at low oxygen partial pressure at 600 °C for 8 h (pO2 = 10–19 Pa) generates a dense, totally black oxide scale. A three step heat treatment process, that was introduced for better coating adhesion, results in a white oxide layer with many micro cracks parallel to the surface. From the results of various microscopy and spectroscopy techniques, we derive a model of the layer formation of zirconia on ZrNb7 and give reason why black zirconia, and therefore the oxidation at low oxygen partial pressure, is favorable for tribological applications (e.g., artificial joint replacements).

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Improvement in oxidation resistance of the intermetallic compound titanium aluminide by heat treatment under a low partial pressure oxygen atmosphere

High Temperature Technology ◽

10.1080/02619180.1990.11753477 ◽

1990 ◽

Vol 8 (3) ◽

pp. 179-184 ◽

Cited By ~ 25

Author(s):

E. Kobayashi ◽

M. Yoshihara ◽

R. Tanaka

Keyword(s):

Heat Treatment ◽

Intermetallic Compound ◽

Partial Pressure ◽

Oxidation Resistance ◽

Titanium Aluminide ◽

Oxygen Atmosphere ◽

Pressure Oxygen

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Quantitative evaluation of the oxidation behavior of ZrB2-15 vol.%SiC at a low oxygen partial pressure

Vacuum ◽

10.1016/j.vacuum.2012.04.004 ◽

2013 ◽

Vol 88 ◽

pp. 98-102 ◽

Cited By ~ 9

Author(s):

Ai Momozawa ◽

Rong Tu ◽

Takashi Goto ◽

Yuuki Kubota ◽

Hiroshi Hatta ◽

...

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Quantitative Evaluation ◽

Oxidation Behavior ◽

Low Oxygen

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Surface oxidation of Alloy 617 in low oxygen partial pressure He–CO–CO2 environments at 750–850 °C

Corrosion Science ◽

10.1016/j.corsci.2014.10.042 ◽

2015 ◽

Vol 90 ◽

pp. 529-534 ◽

Cited By ~ 6

Author(s):

G. Gulsoy ◽

G.S. Was

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Surface Oxidation ◽

Low Oxygen ◽

Alloy 617

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Enhanced superconductivity in Nd1+xBa2-xCu3O7+δby low oxygen partial pressure annealing

Journal of Electronic Materials ◽

10.1007/bf02649956 ◽

1994 ◽

Vol 23 (11) ◽

pp. 1117-1120 ◽

Cited By ~ 18

Author(s):

M. J. Kramer ◽

A. Karion ◽

K. W. Dennis ◽

M. Park ◽

R. W. McCallum

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Low Oxygen ◽

Enhanced Superconductivity

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Tensile Properties and Creep Behavior of SiC-Based Fibers under Various Oxygen Partial Pressures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.1333 ◽

2005 ◽

Vol 475-479 ◽

pp. 1333-1336 ◽

Cited By ~ 5

Author(s):

Jan Ji Sha ◽

J.S. Park ◽

Tatsuya Hinoki ◽

Akira Kohyama ◽

J. Yu

Keyword(s):

Oxygen Partial Pressure ◽

Partial Pressure ◽

Tensile Properties ◽

Creep Behavior ◽

Elevated Temperatures ◽

Low Oxygen ◽

X Ray Diffraction ◽

Sic Fibers ◽

Partial Pressures ◽

Ar Gas

Three kinds of atmospheres (air, highly-pure Ar and ultra highly-pure Ar gas) with different oxygen partial pressures were applied to investigate the tensile properties and creep behavior of SiC fibers such as Hi-NicalonTM and TyrannoTM-SA. These fibers were annealed and crept at elevated temperatures ranging from1273-1773 K in such environments. After annealing at 1773 K, the room temperature tensile strengths of SiC-based fibers decreased with decreasing the oxygen partial pressure and the near stoichiometric fiber TyrannoTM-SA shows excellent strength retention. At temperatures above the 1573 K, the creep resistance of SiC fibers evaluated by bending stress relaxation (BSR) method under high oxygen partial pressure was lower than that of in low oxygen partial pressure. The microstructural features on these fibers were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

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