Phase Selection in Solidification of Undercooled Co–B Alloys
| Autor: | W. Xu, Xiaoxiao Wei, Michael Ferry, Jinfu Li, J.L. Kang |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Metastable phase diagram Phase selection Materials science Polymers and Plastics Mechanical Engineering Alloy Metals and Alloys Thermodynamics 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Lower temperature Crystallography Mechanics of Materials Metastability Phase (matter) 0103 physical sciences Materials Chemistry Ceramics and Composites engineering 0210 nano-technology Supercooling Eutectic system |
| Zdroj: | Journal of Materials Science & Technology. 33:352-358 |
| ISSN: | 1005-0302 |
| DOI: | 10.1016/j.jmst.2016.09.012 |
| Popis: | A series Co-(18.5–20.7) at.% B melts encompassing the eutectic composition (Co81.5B18.5) were solidified at different degrees of undercooling. It is found that the metastable Co23B6 phase solidifies as a substitute for the stable Co3B phase in the alloy melts undercooled above a critical undercooling value of ~60 K. The Co23B6 and α-Co phases make up a metastable eutectic. The corresponding eutectic composition and temperature are Co80.4B19.6 and 1343 K, respectively. On exposure of the metastable Co23B6 phase at a given temperature above 1208 K, it does not decompose even after several hours. But it transforms by a eutectoid reaction to α-Co + Co3B at lower temperature. |
| Databáze: | OpenAIRE |
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