Dendrite growth morphologies in rapidly solidified Al-4.5wt.%Cu droplets

Marie Bedel (1) , Guillaume Reinhart (1) , Abdoul-Aziz Bogno (2) , Hong-Thinh Nguyen (1) , Elodie Boller (3) , Charles-André Gandin (4) , Hani Henein (2)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
2 Chemical and Materials Engineering Department
3 ESRF - European Synchrotron Radiation Facility
4 CEMEF - Centre de Mise en Forme des Matériaux

The impulse atomization process developed at the University of Alberta (Canada) enables metallic powders to be solidified with controlled process parameters and improved properties. In order to investigate the microstructure morphologies in droplets of Al- 4.5wt.%Cu alloys, three-dimensional reconstructions of several droplets are obtained by using synchrotron X-ray micro-tomography, allowing a visualization of the inner microstructure in three dimensions. The analysis of the reconstructed volumes reveals that a wide range of morphology, from highly branched to "finger-bundle", can be obtained for different droplets of similar diameter and produced in the same batch. Unexpectedly for this alloy, microstructural features also indicate that the development of the dendrite arms (primary and of higher orders) occurs in most droplets along <111> crystallographic axes, instead of the usual <100> directions observed in conventional casting technologies.

Mots clés: Dendrite growth

Domaines: Matériaux

Marie Bedel, Guillaume Reinhart, Abdoul-Aziz Bogno, Hong-Thinh Nguyen, Elodie Boller, et al.. Dendrite growth morphologies in rapidly solidified Al-4.5wt.%Cu droplets. 4th International Conference on Advances in Solidification Processes (ICASP-4), Jul 2014, Windsor, UK, United Kingdom. pp.012055, ⟨10.1088/1757-899X/117/1/012055⟩. ⟨hal-01353715⟩