Multiple-Equiaxed-Dendrite-Interaction (MEDI)

MEDI houses the CETSOL-MEDI experiment, of PI L. Sturz, ACCESS e.V. , Aachen, Germany. Scientific Team Coordinator is Gerhard Zimmermann, ACCESS e.V., Aachen, Germany.

The general objective of the CETSOL project is to improve the understanding of the physical phenomena that govern the formation of the columnar-to-equiaxed transition (CET) in alloy solidification and its consequences for casting soundness. For that purpose, both experimental investigations of the formation of columnar and equiaxed dendritic solidification and the CET, as well as numerical models are being developed.

In the frame of the experiment MEDI on MASER 13 the team proposes to investigate the formation of an equiaxed microstructure under low gravity conditions.

Scientific objectives and concept for MEDI:

Objectives: Investigate, characterize and validate models for:

  • Single equiaxed dendrite growth & multiple equiaxed dendrite interaction in 3D and in-situ
  • Perform microgravity experiments to avoid melt convection and crystal sedimentation
  • Identify gravity effect by comparison to reference experiments on ground

Experimental concept:

  • Decrease thermal gradient and cooling rate to obtain purely equiaxed growth
  • Determine temperature field by thermocouples
  • Determine equiaxed dendrite density in time (overview image)
  • Determine single equiaxed dendrite 3D orientation in space and growth rate (detail image)

Determine effect of interaction of (some) adjacent crystals in morphology&speed (detail image)

MEDI Teams at the campaign:

ACCESS e.V.: Dr. Lazlo Sturz, Dr. Gerhard Zimmermann
Airbus DS : Burkhard Schmitz, Andreas Stein ,Stefan Feldmann
SSC: Mikael Inga