| Autor: |
Hans-Jürgen Schaller, Knuth Albertsen |
| Rok vydání: |
1994 |
| Předmět: |
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| Zdroj: |
Berichte der Bunsengesellschaft für physikalische Chemie. 98:1224-1230 |
| ISSN: |
0005-9021 |
| DOI: |
10.1002/bbpc.19940981003 |
| Popis: |
Diffusion of carbon in titanium carbide was investigated over the entire phase field between 1179 and 2413 K using suitably designed diffusion couples. Concentration-depth profiles of carbon were taken by SNMS and EMPA. The diffusion coefficients of carbon obtained by the two analytical techniques in different temperature ranges agree remarkably well. Above 1468 K, they exhibit a strong concentration dependence and can be expressed by The thermodynamic factor obtained from a thermodynamic analysis of the TiC system was used to describe the concentration dependence. Tracer diffusion coefficients calculated from the chemical diffusion coefficients with the help of the thermodynamic factor are in accordance with literature data. Below 1468 K concentration-independent diffusion coefficients were obtained which yielded a lower energy of activation: This behavior is attributed to the preponderance of grain boundary diffusion over volume diffusion at low temperatures in the samples at hand. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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