Microstructural evolution during laser resolidification of Fe-25 atom percent Ge alloy

Biswas, Krishanu and Chattopadhyay, Kamanio (2007) Microstructural evolution during laser resolidification of Fe-25 atom percent Ge alloy. In: Symposium on Solidification Modeling and Microstructure Formation held at the 2006 TMS Annual Meeting, MAR 13-16, 2006, San Antonio.

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Abstract

The microstructural evolution of concentrated alloys is relatively less understood both in terms of experiments as well as theory. Laser resolidification represents a powerful technique to study the solidification behavior under controlled growth conditions. This technique has been utilized in the current study to probe experimentally microstructural selection during rapid solidification of concentrated Fe-25 atom pct Ge alloy. Under the equilibrium solidification condition, the alloy undergoes a peritectic reaction between ordered alpha(2) (B2) and its liquid, leading to the formation of ordered hexagonal intermetallic phase epsilon (DO19). In general, the as-cast microstructure consists of epsilon phase and e-p eutectic and alpha(2) that forms as a result of an incomplete peritectic reaction. With increasing laser scanning velocity, the solidification front undergoes a number of morphological transitions leading to the selection of the microstructure corresponding to metastable alpha(2)/beta eutectic to alpha(2) dendrite + alpha(2)/beta eutectic to alpha(2) dendrite. The transition velocities as obtained from the experiments are well characterized. The microstructural selection is discussed using competitive growth kinetics.

Item Type:	Conference Paper
Publisher:	The Minerals, Metals & Materials Society.
Additional Information:	Copyright of this article belongs to The Minerals, Metals & Materials Society.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	10 Jun 2010 10:48
Last Modified:	19 Sep 2010 05:59
URI:	http://eprints.iisc.ac.in/id/eprint/27092

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