Design And Evaluation Of Lunar Regolith Simulant Composites For UV-Assisted Direct Ink Write In Extreme Cold

With the anticipated return of humans to the lunar surface, a growing area of interest is infrastructure development on the Moon facilitated through additive manufacturing. While the Moon presents challenges to manufacturing, including a harsh environment and limited resources, direct ink write (DIW) 3D printing and its versatile ink formulations can be carried out in extreme cold temperatures and allows for high amounts of regolith particles native to the lunar surface to be utilized within the inks. However, ink flow complications arise with solid loadings over 60 vol%, and ink extrusion and solidification mechanisms are not well understood at sub-zero temperatures. In this thesis, I first present parameters that bridge ink rheology and printing extrusion quality to predict and mitigate composition change in high solid DIW inks. Then I discuss considerations to modify commercial DIW printers for optimal operation at -30°C following proof-of-concept printing of inks containing glass microspheres. The curing kinetics of various UV cure inks are also investigated when printing at -30°C with crosslinked microstructures compared to those obtained in ambient printing. Lastly, the effect of both printing at -30°C and subsequent lunar thermal weathering on the degradation of lunar regolith composite prints are examined. Throughout this work, several ink design parameters, including the bimodal ratio of particle size, the solid loading, and the thermal behavior of the UV cure binders, prove to be critical to ensure printing success and to produce desired mechanical properties. The work described in this thesis will contribute to facilitating progress in space exploration by enabling manufacturing methods in environments significantly different from Earth.

Date

2024-04-27

Resource Type

Text

Resource Subtype

Dissertation

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