Studying flow effects on dendrite fragmentation using Rayleigh–Bénard convection

Abstract

The present paper reports on an in situ experiment to investigate the effects of fluid flow on dendrite fragmentation. A Bénard cell was constructed for the solidification of a transparent alloy under Rayleigh–Bénard convection. Dendrite fragmentation was observed, and the flow field was mapped. It was found that a Bénard cell provides a useful apparatus for studying dendrite fragmentation under controlled conditions in transparent alloys. Preliminary results showed that structural fragmentation occurs under relatively quiescent flow conditions, suggesting that deformation processes play little role in this system.

Keywords:

• Solidification
• Dendrite
• Fluid flow
• Fragmentation

The author is grateful to P. S. Grant, J. Mi, R. C. Vincent, T. Knibbs and R. Turner for their assistance in the design and construction of the experiments performed.