Oxidation Behaviors of C–ZrB2–SiC Composite at 2100 °C in Air and O2
| Autor: | Zeng-Hua Gao, Jingjun Xu, Jun-shan Wang, Zhong-wei Zhang, Ce-Wen Nan, Meishuan Li |
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| Rok vydání: | 2014 |
| Předmět: |
Induction heating
Materials science Polymers and Plastics Mechanical Engineering Diffusion Composite number Metals and Alloys Oxide chemistry.chemical_element Substrate (electronics) Partial pressure Oxygen chemistry.chemical_compound chemistry Chemical engineering Mechanics of Materials Materials Chemistry Ceramics and Composites Graphite |
| Zdroj: | Journal of Materials Science & Technology. 30:1223-1229 |
| ISSN: | 1005-0302 |
| DOI: | 10.1016/j.jmst.2014.04.013 |
| Popis: | The oxidation behaviors of graphite and ZrB 2 –SiC modified graphite composite were investigated at 2100 °C in 1 × 10 5 Pa air and 0.2 × 10 5 Pa O 2 . The oxidation tests were conducted in an induction heating furnace. The oxidation of these two materials followed the linear rate law. The determined radius loss rates of graphite and C–ZrB 2 –SiC at 2100 °C were 2.18 × 10 −2 and 1.05 × 10 −2 %/s in 1 × 10 5 Pa air, and 3.23 × 10 −2 and 2.21 × 10 −2 %/s in 0.2 × 10 5 Pa O 2 , respectively. The incorporation of ZrB 2 and SiC decreased remarkably the oxidation rate of graphite because the oxide scale formed on the sample surface during oxidation helps in reducing the exposed surface area of the underneath substrate. In two different atmospheres with the same oxygen partial pressure, both graphite and C–ZrB 2 –SiC experienced more severe oxidation at 2100 °C in 0.2 × 10 5 Pa O 2 than in 1 × 10 5 Pa air. The oxidation rate-controlling step for graphite and C–ZrB 2 –SiC was proposed to be the inward diffusion of oxygen through the boundary layer and through the pores in the oxide scale, respectively. A model based on diffusion theory was established to discuss the effect of the total gas pressure on their oxidation behaviors. |
| Databáze: | OpenAIRE |
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