Hot working behavior of extruded powder products of B2 iron aluminide alloys

Prasad, YVRK and Sastry, DH and Deevi, SC (2001) Hot working behavior of extruded powder products of B2 iron aluminide alloys. In: Materials Science and Engineering A, 311 (1-2). pp. 42-53.

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Abstract

The characteristics of hot deformation of hot extruded B2 type iron aluminide alloy powders produced by gas-atomization and water-atomization techniques have been studied using compression tests in the temperature range 850–1150°C and true strain rate range 0.001–100$_{s-^1}$. At strain rates higher than about 1 $_{s-^1}$, the materials exhibited flow softening type of stress–strain curves, while at lower strain rates, the flow curves were of steady-state type. The apparent activation energy for hot deformation has been evaluated and is in the range 430–465 kJ $mole^-1$ both in the gas-atomized and water-atomized materials. The processing map for the gas-atomized material revealed that dynamic recrystallization occurs in wide ranges of temperature and strain rate with its optimum at 1075°C and 0.1 $_{s-^1}$. However, in the case of water-atomized material, the features in the processing map have changed with strain. The gas-atomized material is prone to flow instabilities like flow localization at strain rates higher than 10 $_{s-^1}$, while the water-atomized material exhibits stable flow even at high strains and high strain rates.

Item Type:	Journal Article
Publication:	Materials Science and Engineering A
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Iron aluminide;Hot working;Processing maps;Dynamic recrystallization;Superplasticity;Flow localization
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	06 Jun 2006
Last Modified:	19 Sep 2010 04:29
URI:	http://eprints.iisc.ac.in/id/eprint/7529

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