Solidification of intermetallic Ni-Al alloy melts under reduced gravity conditions during parabolic flight experiments: promising results for MSL-EML onboard the ISS

Paper number

IAC-08.A2.3.7

Author

Dr. Sven Reutzel, German Aerospace Center (DLR), Germany

Coauthor

Mrs. Helena Hartmann, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Germany

Coauthor

Mr. Roman Lengsdorf, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Germany

Coauthor

Mr. Peter Galenko, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Germany

Coauthor

Prof. Dieter Herlach, Institute of Space Simulation, German Aerospace Center (DLR), Germany

Year

2008

Abstract

Solidification of alloys is a complex phenomenon coming into effect in many modern experimental techniques and industrial technologies involving casting and surface processing. Deep undercooling of metallic alloy melts below equilibrium liquidus temperature results in rapid solidification, yielding materials bearing improved mechanical, magnetic or electrical properties. Containerless processing techniques enable the measurement of the undercooling prior to solidification and the dendrite growth velocity as a function of undercooling. Those are essential parameters for modelling the process of crystal growth and microstructural evolution.
This work funded by ESA within the Microgravity Application Promotion Project NEQUISOL [1] presents containerless processing experiments using electromagnetic levitation technique on intermetallic Ni-Al alloy melts. The comparative experiments are conducted under different levels of gravity: firstly under terrestrial conditions and secondly under reduced gravity conditions, using the TEMPUS facility during parabolic flights. The TEMPUS facility is a precursor to MSL-EML (Materials Science Laboratory - Electromagnetic Levitator), currently under development in joint venture between ESA and DLR for the adoption in the ESA Columbus laboratory onboard the ISS. 
The comparison of experimental investigations of intermetallic Ni-Al on Earth and in reduced gravity allows for the determination of effects by forced convection to the growth dynamics. The evolution of grain refined microstructures upon undercooling within the limited time of reduced gravity during parabolic flight experiments is further demonstrated [2]. The recent results establish the significance of comparative solidification experiments under weightlessness for ground based research and microstructure modelling of industrial alloys. The need of long-term experiments onboard the ISS using MSL-EML is herewith ascertained.

[1] D.M. Herlach, C.-A. Gandin, A. Garcia-Escorial, and H. Henein, NEQUISOL: Non-Equilibrium Solidification in Microgravity: Microstructure Modelling of Industrial Alloys, ESA MAP-99-023
[2] S. Reutzel, H. Hartmann, P.K. Galenko, S. Schneider, and D.M. Herlach, Applied Physics Letters, Vol.91, 4, (2007), 041913

Abstract document

IAC-08.A2.3.7.pdf

Manuscript document

IAC-08.A2.3.7.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.