Grain refinement induced by a critical crystal growth velocity in undercooled melts
- 22 January 1990
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 56 (4), 324-326
- https://doi.org/10.1063/1.103289
Abstract
Containerless undercooling by electromagnetic levitation has been used to measure both growth velocity and grain size as a function of undercooling in Cu70Ni30 and Cu69Ni30B1 alloys. At a critical undercooling ΔT* the temperature dependence of the growth velocity changes discontinuously. This is accompanied by a sudden drop of grain size in the solidified product by more than two orders of magnitude. The comparative investigations show that it is not a critical undercooling that initiates the grain refinement process, but rather a critical crystal growth velocity, which approximately equals the diffusive speed.Keywords
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