Study of the Oxidation Dynamics of TiZrO₂ Metal-ceramics

Authors

Wen-chao LI, Univ. of Sci. and Techn. Beijing, Beijing 100083, ChinaFollow
Li-dong TENG, Univ. of Sci. and Techn. Beijing, Beijing 100083, China

Corresponding Author

Wen-chao LI(liwenchao@metall.ustb.edu.cn)

Abstract

The oxidation dynamics of hot-pressed Ti-ZrO₂ metal-ceramics with the compositionof 50 vol.% Ti and 50 vol.% ZrO₂ has been studied.Thermodynamic analysis shows that Ticould react with O₂ but not with N₂ in the oxidizing process of TiZrO₂ composites at 0.1 MPa air. The oxidation dynamic behavior of Ti-ZrO₂ composites is analogous to that of pure Ti. Theactivation energy for the oxygen diffusion in Ti-ZrO₂ composites is higher than that in Ti solutions, for the presence of ZrO₂ restrains the oxygen diffusion in Ti-ZrO₂ composites. At early stagethe oxidation of Ti-ZrO₂ composites follows a parabolic rate law between 700 and 1000 ℃. The main reaction products in the oxide scale are rutile mo dification of TiO₂ with little amount of ZrTiO₄ determined by XRD and TEM. SEM observations show that there are two kinds of cracks inthe oxide scale. One exists at the ZrO₂/Ti interfaces arising from the thermal expansion mismatch between ZrO₂ and Ti or TiO₂. The other kind of cracks resulting from the thermal expansion mismatch between the oxide scale and the substrate is often parallel to the sample surface. The presence of ZrO₂ in Ti-ZrO₂ composites can restrain the extension of the second kind of cracks.

Keywords

Ti-ZrO2 system, MetaFceramics, Reaction thermodynamics, Oxidation dynamics, Micrstructure

DOI Link

https://doi.org/10.61558/2993-074X.3253

Publication Date

2001-05-28

Online Available Date

2001-05-28

Revised Date

2001-03-14

Received Date

2000-12-29

Recommended Citation

Wen-chao LI, Li-dong TENG. Study of the Oxidation Dynamics of TiZrO₂ Metal-ceramics[J]. Journal of Electrochemistry, 2001 , 7(2): 220-227.
DOI: 10.61558/2993-074X.3253
Available at: https://jelectrochem.xmu.edu.cn/journal/vol7/iss2/15