Microstructure of the Sn-Cu{sub 6}Sn{sub 5} fibrous eutectic and its modification by segregation
- CEA/DTA/CEREM/DEM, Grenoble (France). Lab. de Recherche de Base en Solidification
- CEA/DTA/LETI/OPT, Grenoble (France). Section de Caracterisation Physique des Materiaux
The influence of segregation due to thermal convection on the microstructure of Sn-Cu{sub 6}Sn{sub 5} fibrous eutectic alloys is studied in a Bridgman type configuration. The eutectic microstructure is characterized by means of image analysis, X-ray diffraction and scanning and transmission electron microscopy. In the absence of segregation, the eutectic is regular and its growth controlled by that of the Cu{sub 6}Sn{sub 5} fibers. The effect of interphases on eutectic spacing, through orientation relationships between fibers and matrix, is also evidenced. The influence of segregation can be summed up by the following effects. At first, in agreement with the Jackson and Hunt model, it leads to a variation of the eutectic spacing which results from a variation of the fiber volume fraction. Then, the spacing is much greater than the one obtained in the absence of segregation, due to a different tin growth plane and non-optimized fiber/matrix orientation relationships. Finally, the absence of steady state leads to a large dispersion of the spacing associated with a microstructural disorder.
- OSTI ID:
- 415403
- Journal Information:
- Acta Materialia, Vol. 44, Issue 10; Other Information: PBD: Oct 1996
- Country of Publication:
- United States
- Language:
- English
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