Melting and solidification

PIV studies, using a transparent alloy (NH4Cl), of the interaction between the solidification and the flow​

  • Different flow regimes were observed during solidification.
  • In area with a high amount of equiaxed crystals the turbulence of the flow is damped. The flow is dragged by equiaxed crystals.
  • The relative velocity between crystals and flow was calculated. A power tendency was found between the relative velocity of isolated crystals and the crystal diameter.
  • For high flow velocity and large solidification front velocity, equiaxed crystals were observed.
  • Clear correlation between flow kinetic energy and occurrence of equiaxed crystals were observed. The flow KE always presents a peak during the equiaxed crystals‘ rain.
  • Coupling mechanism between flow intensity and equiaxed crystals occurrence was proposed, which can explain CET.

Dual PIV-Setup to study columnar & equiaxed solidification