Artículos de revistas
Growth and microstructure evolution of the Nb(2)A-Al3Nb eutectic in situ composite
Registro en:
Materials Characterization. Elsevier Science Inc, v. 54, n. 3, n. 187, n. 193, 2005.
1044-5803
WOS:000227829200001
10.1016/j.matchar.2004.08.017
Autor
Rios, CT
Ferrandini, PL
Milenkovic, S
Caram, R
Institución
Resumen
In situ composite materials obtained by directional growth of eutectic alloys usually show improved properties, that make them potential candidates for high temperature applications. The eutectic alloy found in the Al-Nb system is composed of the two intermetallic phases Al3Nb (D0(22)) and Nb2Al (D(8)b). This paper describes the directional solidification of an Al-Nb eutectic alloy using a Bridgman type facility at growth rates varying from 1.0 to 2.9 cm/h. Longitudinal and transverse sections of grown samples were characterized regarding the solidification microstructure by using optical and scanning electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffraction. Despite both phases being intermetallic compounds, the eutectic microstructure obtained was very regular. The results obtained were discussed regarding the effect of the growth rate on the microstructure, lamellar-rod transition and variation of phase volume fraction. (c) 2004 Elsevier Inc. All rights reserved. 54 3 187 193