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Effect of crystallization on the surface area of porous Ni-based metallic glass foams |
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| Authors: | J.S. Kim S. Yi Daniel J. Sordelet U. Kühn J. Eckert |
| Affiliation: | 1. Production Technology R&2. D Division, Korea Institute of Industrial Technology , Incheon 406-840, Korea;3. Department of Metallurgical Engineering , Yonsei University , Seoul 120-749, Korea;4. Department of Materials Sciences and Metallurgy , Kyungpook National University , Daegu 702-701, Korea;5. Caterpillar Advanced Materials Technology Group, Mossville , Illinois 61552, USA;6. IFW Dresden, Institute for Complex Materials , P.O. Box 27 01 16, D-01171 Dresden, Germany;7. IFW Dresden, Institute for Complex Materials , P.O. Box 27 01 16, D-01171 Dresden, Germany;8. TU Dresden, Institute of Materials Science , D-01062 Dresden, Germany |
| Abstract: | The change of the specific surface area in porous Ni59Zr20Ti16Si2Sn3 metallic glass (MG) upon partial crystallization was investigated. The observed increase in the surface area of the annealed Ni-based MG foams is due to the formation of homogeneously distributed Ni10(Zr,Ti)7 rod-shape intermetallic phases with nominal diameters around 250?nm and ～800?nm length on the surface of MG struts during the crystallization. For longer annealing, the specific surface area decreases again due to a change of the morphology of the crystals from rod-like to disc-like appearance, thus suggesting an optimum regime for increasing the specific surface area upon isothermal annealing at a given temperature. |
| Keywords: | crystallization foams intermetallics metallic glasses metastable phases porous media powder metallurgy rapidly solidified materials |