J. Phys. IV France
Volume 123, March 2005
Page(s) 117 - 120

J. Phys. IV France 123 (2005) 117-120

DOI: 10.1051/jp4:2005123019

Fe-NiAl based alloys: Phase transformations and microstructure due to cobalt addition

G. Marcon1, S. Lay1, B. Djerdjare2 and S. Lebaili2

1  Laboratoire de Thermodynamique et Physico-Chimie Métallurgiques UMR 5614, INPG, CNRS/UJF, BP. 75, Domaine Universitaire, 38402 Saint-Martin-d'Hères Cedex, France
2  Laboratoire de Science et Génie des Matériaux, Université des Sciences et de la Technologie Houari Boumédienne, BP. 32, El-Alia Bab-Ezzouar, Alger, Algérie

Structural characterisation of (Fe, Co)-NiAl alloys containing 0-50 at. % Co was performed. In alloys containing more than 15 at. % Co a high-temperature bcc $\alpha$ phase is partly transformed, when cooled, to a $\gamma$ phase, which at lower temperature is allotropically transformed into a $\alpha _{\gamma }$ phase. The untransformed $\alpha$ phase, according to Co content, is then transformed by a demixtion process into two $\alpha _{1}$ and $\alpha _{2}$ phases. The main cobalt addition effects on the Fe-NiAl based alloy are: the appearance of the $\gamma$ phase, a decrease of demixtion temperature, an increase of Curie temperature and a microstructure refining.

© EDP Sciences 2005