skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Solidification kinetics and phase formation of undercooled eutectic Ni-Nb melts

Abstract

The non-equilibrium solidification behavior of undercooled eutectic Ni{sub 84}Nb{sub 16} and Ni{sub 59.5}Nb{sub 40.5} melts has been analyzed by in situ observation of recalescence events during electromagnetic levitation of undercooled melts. Levitated drops of controlled undercooling were quenched onto chill substrates and subjected to phase and microstructure analysis. For Ni{sub 84}Nb{sub 16} a maximum melt undercooling of 276 K has been achieved. A transition from coupled eutectic to primary supersaturated {alpha}-Ni dendrite growth has revealed beyond a critical undercooling of 30 K. Beyond 110 K the primary Ni{sub 3}Nb phase occurred for substrate quenching. The undercooling of Ni{sub 59.5}Nb{sub 40.5} melt was limited to 135 K. Bulk amorphous samples up to 2 mm thick have been prepared by quenching of undercooled Ni{sub 59.5}Nb{sub 40.5} melts. On slow cooling the metastable phases decompose into an anomalous eutectic microstructure.

Authors:
; ;  [1]
  1. Inst. fuer Festkoerper- und Werkstofforschung Dresden (Germany)
Publication Date:
OSTI Identifier:
684396
Resource Type:
Journal Article
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 47; Journal Issue: 10; Other Information: PBD: 10 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; SOLIDIFICATION; PHASE STUDIES; NICKEL ALLOYS; NIOBIUM ALLOYS; EUTECTICS; LIQUID METALS; METALLIC GLASSES; PHASE TRANSFORMATIONS

Citation Formats

Leonhardt, M., Loeser, W., and Lindenkreuz, H.G. Solidification kinetics and phase formation of undercooled eutectic Ni-Nb melts. United States: N. p., 1999. Web. doi:10.1016/S1359-6454(99)00167-6.
Leonhardt, M., Loeser, W., & Lindenkreuz, H.G. Solidification kinetics and phase formation of undercooled eutectic Ni-Nb melts. United States. doi:10.1016/S1359-6454(99)00167-6.
Leonhardt, M., Loeser, W., and Lindenkreuz, H.G. Tue . "Solidification kinetics and phase formation of undercooled eutectic Ni-Nb melts". United States. doi:10.1016/S1359-6454(99)00167-6.
@article{osti_684396,
title = {Solidification kinetics and phase formation of undercooled eutectic Ni-Nb melts},
author = {Leonhardt, M. and Loeser, W. and Lindenkreuz, H.G.},
abstractNote = {The non-equilibrium solidification behavior of undercooled eutectic Ni{sub 84}Nb{sub 16} and Ni{sub 59.5}Nb{sub 40.5} melts has been analyzed by in situ observation of recalescence events during electromagnetic levitation of undercooled melts. Levitated drops of controlled undercooling were quenched onto chill substrates and subjected to phase and microstructure analysis. For Ni{sub 84}Nb{sub 16} a maximum melt undercooling of 276 K has been achieved. A transition from coupled eutectic to primary supersaturated {alpha}-Ni dendrite growth has revealed beyond a critical undercooling of 30 K. Beyond 110 K the primary Ni{sub 3}Nb phase occurred for substrate quenching. The undercooling of Ni{sub 59.5}Nb{sub 40.5} melt was limited to 135 K. Bulk amorphous samples up to 2 mm thick have been prepared by quenching of undercooled Ni{sub 59.5}Nb{sub 40.5} melts. On slow cooling the metastable phases decompose into an anomalous eutectic microstructure.},
doi = {10.1016/S1359-6454(99)00167-6},
journal = {Acta Materialia},
number = 10,
volume = 47,
place = {United States},
year = {1999},
month = {8}
}