Biswas, Kaushik and Hermann, R. and Wendrock, H. and Priede, J. and Gerbeth, G. and Buechner, B. (2009) Effect of melt convection on the secondary dendritic arm spacing in peritectic Nd-Fe-B alloy. Journal of Alloys and Compounds, 480 (2). pp. 295-298. ISSN 0925-8388

PDF - Published Version Restricted to Registered users only Download (781Kb) | Request a copy

Abstract

Dendrites are one of the major microstructural constituents of peritectic alloys. In the present work, the effect of melt convection on the secondary dendritic arm spacing (SDAS) and volume fraction of properitectic alpha-Fe was investigated during solidification of stoichiometric Nd-Fe-B alloys using the forced crucible rotation technique. The resulting microstructure of the alloy in consideration of melt convection has been investigated using scanning electron microscopy and optical microscopy. The average SDAS was determined for each sample from the whole cross-section of the cylindrical test samples using image analyzing software LEICA QWIN. A detailed statistical analysis of the spacing distribution was performed on the basis of the variation of SDAS values, averaged from about 80 to 120 dendrites in different zones. The alpha-Fe volume fraction, measured by vibrating sample magnetometer (VSM), reduces with increasing crucible rotation frequency. Similarly, the SDAS values decrease with increasing rotation frequency. These results are explained from the viewpoint of a reduced melt convection state under steady forced crucible rotation leading to a reduced effective mass transfer coefficient. (C) 2009 Published by Elsevier B.V.

Item Type:	Article
Uncontrolled Keywords:	Peritectic solidification; Nd-Fe-B; Secondary dendritic arm spacing; Melt-convection
Subjects:	Engineering Materials
Divisions:	UNSPECIFIED
Depositing User:	Ashok K Podder
Date Deposited:	22 Feb 2012 05:35
Last Modified:	22 Feb 2012 05:35
URI:	http://cgcri.csircentral.net/id/eprint/978

Actions (login required)

View Item