OS3-4
Hetero-3DTi

TiC
ISS-ELF

Melting and Solidification Experiments of Ti Alloy
Samples with TiC by ISS-ELF in Hetero-3D Mission
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Shinsuke SUZUKI , Chihiro HANADA , Yuji MABUCHI 1, Hirokazu AOKI 1, Yuto UEDA 1,Koei KADOI 1, Yuta KUSHIYA 1, Motoko YAMADA 2, Ryosei SAGUCHI 2, Kanae YONEDA 2,Hisashi SATO 2, Yoshimi WATANABE 2, Yusaku SEIMIYA 3, Yuma HARADA 3, Shumpei OZAWA 3,Takuro USUI 4, Kohei TANIMOTO 4, Suguru SHIRATORI 4, Shizuka NAKANO 5,Takehiko SONE 6, Kazunori ENOKIDO 6, Yuki WATANABE 7, Hirohisa ODA 8, Chihiro KOYAMA 8,Rumiko IKEUCHI 8, Rina SHIMONISHI 8, and Takehiko ISHIKAWA 8112345678, Waseda University,, Nagoya Institute of Technology,, Chiba Institute of Technology,, Tokyo City University,
Henry Monitor, Henry Monitor Inc.,, Japan Manned Space Systems Corporation (JAMSS),, Advanced Engineering Services (AES),, Japan Aerospace Exploration Agency (JAXA)

1. Introduction
The orbital experiments of the JAXA's science experimental theme “Heterogeneous solidification behaviorof powder metals for 3D printer” (Abbreviation: Hetero-3D, PI: S. Suzuki, Waseda University) were carried out
with the electrostatic levitation furnace in the International Space Station (ISS-ELF) as planned in 2023. The
objective of this study is to investigate the effects of heterogeneous nucleation site particles on solidification
behavior of metals by microgravity space experiments, which are ideal methods to exclude the effects ofcontamination from the container, evaporation and convection1). The heterogeneous nucleation site particles
are added in metallic powder to refine crystal grains in 3D printing of metals. The obtained results are applied
to improve the physical properties of the built products. This presentation introduces the overview and current
status of the Hetero-3D mission.
2.

Mission Progress and Future Plans
The pure Ti and Ti6Al4V samples with and without TiC were prepared and inspected2). These samples, two

Zr samples as oxygen getters, and a stainless-steel sample for scale-calibration were inserted in a cartridge for
1 of 2the ISS-ELF on June 29, 2022.
The samples in the cartridge were set in a spacecraft Space-X Cargo Dragon. They were launched by a rocket
Space-X Falcon 9 at the Kennedy Space Center as a commercial resupply service mission CRS-26 and arrived
at ISS on November 27, 2022 (JST).
All of the planned orbital experiments were performed on eight days from April 14 to May 15, 2023(JST).
Sixteen samples were levitated, melted and solidified as planned. Although only the first sample was lost
during the levitation, the optimum levitation condition was found in this experiment. Since its spare sample
was melted, necessary experiments were carried out. The samples was recovered to the earth by Space-X SpX28 mission in June 30 2023, and will be observed and analyzed after recovery to our laboratory.
3.

Experimental Procedure in ISS-ELF
In the beginning of every experimental day, the furnace was evacuated and filled with Ar gas. Then a Zr

sample was melted in Ar atmosphere as an oxygen getter. A few runs of experiments were performed on everyexperimental day.
In every run, the sample position was controlled to be the center of the view by adjusting the voltage of theelectrodes. The sample was heated by four laser beams and recorded by a high-speed camera. The temperatureof the sample was measured by a pyrometer. When the temperature exceeded the melting temperature, theheating was stopped automatically. After cooling, the sample was recovered into the cartridge. Thetemperature and video data were acquired by telemetry.
4.

Results
The obtained cooling curves showed that the samples with TiC tend to solidify with a smaller degree ofundercooling than those without TiC, which implies the refinement effect by TiC. Crystal growth could beobserved clearly in the video data obtained from the high-speed camera during the solidification of thesamples, the grains of which are considered to be coarsened.
5.

Summary(1) The orbital experiments conducted in the Hetero-3D mission were largely successful, which meets themajority of predefined objectives and milestones.
(2) The telemetry data of temperature and video implied the refinement effect of crystal grains by TiC.
References
1)

2)

T.Usui, S. Shiratori, K. Tanimoto, S. Ozawa, T. Ishikawa, S. Suzuki, H. Nagano, and K. Shimano: Surrogate Models
for the Magnitude of Convection in Droplets Levitated through EML, ADL, and ESL Methods. Int. J. Microgravity
Sci. Appl., 40 (2023) 400302 , DOI: https://doi.org/10.15011/jasma.40.400302.
C. Hanada, H. Aoki, Y. Ueda, K. Kadoi, Y. Mabuchi, K. Yoneda, M. Yamada, H. Sato, Y. Watanabe, Y. Harada, S.
Ozawa, S. Nakano, C. Koyama, H. Oda, T. Ishikawa, Y.Watanabe, T. Shimaoka and S. Suzuki: Suppression of Bubble
Formation in Levitated Molten Samples of Ti6Al4V with TiC for Hetero-3D at the International Space Station (ISS).
Int. J. Microgravity Sci. Appl., 40 (2023) 400301, DOI: https://doi.org/10.15011/jasma.40.400301.
© 2023 by the authors. Submitted for possible open access publication under theterms and conditions of the Creative Commons Attribution (CC BY) license(http://creativecommons.org/li censes/by/4.0/).
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