Directional solidification and characterization of binary Fe-Pr and Fe-Nd eutectic alloys

In this work, the directional solidification technique was employed in binary Fe-Pr and Fe-Nd eutectic alloys with compositions near to their respective eutectic points. Solidifying the Fe-Pr and Fe-Nd hypereutectic alloys in a vertical Bridgman crystal growth unit, we were able to obtain the two eutectic morphologies, one globular and other feathered, normally observed in as-cast samples, in a coarser form and sequentially displayed along the length of the samples. The transition temperatures nearby to the eutectic points were also determined using a Calvet type calorimeter. The phases comprising the globular and feathered morphologies were determined as being, respectively, Fe17R2 and Fe2R (R=Pr or Nd), for both systems. These experiments also showed very clearly the peritectic formation of the Fe2R phases from the Fe17R2 and the liquids. Thermomagnetic measurements gave the Curie temperature as being 44 degreesC for the Fe2Pr phase and 252 degreesC for the Fe2Nd phase. (C) 2001 Elsevier Science B.V. All rights reserved.3254167119420