Assessing extraterrestrial regolith material simulants for in-situ resource utilisation based 3D printing

This research paper investigates the suitability of ceramic multi-component materials, which are found on the Martian and Lunar surfaces, for 3D printing (aka Additive Manufacturing) of solid structures. 3D printing is a promising solution as part of the cutting edge field of future in situ space manufacturing applications. 3D printing of physical assets from simulated Martian and Lunar regolith was successfully performed during this work by utilising laser-based powder bed fusion equipment. Extensive evaluation of the raw regolith simulants was conducted via Optical and Electron Microscopy (SEM), Visible-Near Infrared/Infrared (Vis-NIR/IR) Spectroscopy and thermal characterisation via Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The analysis results led to the characterisation of key properties of these multi-component ceramic materials with regard to their processability via powder bed fusion 3D printing. The Lunar and Martian simulant regolith analogues demonstrated spectral absorbance values of up to 92% within the Vis-NIR spectra. Thermal analysis demonstrated that these materials respond very differently to laser processing, with a high volatility (30% weight change) for the Martian analogue as opposed to its less volatile Lunar counterpart (<1% weight change). Results also showed a range of multiple thermal occurrences associated with melting, glass transition and crystallisation reactions. The morphological features of the powder particles are identified as contributing to densification limitations for powder bed fusion processing. This investigation has shown that - provided that the simulants are good matches for the actual regoliths - the lunar material is a viable candidate material for powder bed fusion 3D printing, whereas Martian regolith is not. (C) 2016 Elsevier Ltd. All rights reserved.