3D printing goes to be a essential expertise in house exploration, each for its means to create nearly any object, but in addition as a result of it could actually make the most of in-situ sources, no less than partially. Nonetheless, the extra of these house sources are utilized in a print, the extra the mechanical properties change from that on Earth, resulting in issues with tensile or compressive power. However a brand new paper from researchers at Concordia College hit a brand new milestone of how a lot lunar regolith can be utilized in a combined feedstock for additive manufacturing, making it potential to make use of much more regionally sourced materials, and saving extra launch value, than ever earlier than.
The analysis combined lunar regolith simultant, which is materials created to imitate how the fabric on the floor on the Moon works, with polyether-ether-ketone, extra generally often known as PEEK. PEEK is a thermoplastic already in broad use in 3D printing, however earlier efforts to mix it with lunar regolith have faltered. They suffered from extrusion challenges, because the regolith, which is made up of onerous particular person particles, made it tough to extrude with out merely blowing mud throughout. Extra issues resulted from the porosity of the fabric that was printed, which led to decreased tensile power and elevated brittleness.
Modifications to the 3D printing technique gave the impression to be the reply to these issues. There have been two primary developments in expertise mentioned within the paper – a screw configuration and a unique kind of “raft” used to bond the printed materials to the print mattress.
Fraser discusses how sources on the Moon are going to be so vital to our growth of the photo voltaic system.
Combining lunar regolith simulant (LRS) with PEEK is a tough enterprise, so the researchers, led by Mohammed Azami of Concordia’s electrical engineering division, determined to make use of a novel “twin screw” configuration. Torque was a consider earlier iterations of the blending machine, as increased regolith content material meant increased torque, finally limiting the full proportion of regolith combined with the PEEK to round 30%. With the brand new configuration, the researchers have been in a position to get concentrations of as much as 50% of the regolith when mixed with the PEEK.
Nonetheless, when these elements have been printed, they began to delaminate and warp. Whereas frequent in prints of simply PEEK itself, the addition of the regolith exacerbated the issue. To resolve it, the researchers used a “raft” – a kind of intermediate layer to assist the print bond to the primary printing plate. Of their case, they used a unique kind of thermopolymer, often known as polyether-ketone-ketone (PEKK) because the raft, and carried out a dual-nozzle system, the place the PEKK was printed utilizing one nozzle and the mixture LRS/PEEK was printed utilizing the opposite.
After they obtained the upper concentrations of LRS and overcame the delamination/warping downside, the researchers determined to anneal their samples. The annealing course of appeared to enhance a number of the mechanical properties of the print, however solely up to some extent. At increased concentrations of LRS, the advantages of annealing weren’t as obvious because of breaks in PEEK’s polymer chain, which advantages from annealing, due to the elevated variety of regolith particles.
Fraser discusses why 3D printing is so essential to house exploration.
As with all good papers on 3D printing new materials, the authors then seemed on the mechanical properties of their output. Whereas there was a noticeable enhance in stiffness, there was a gentle lower in tensile power, which was exacerbated at increased LRS concentrations. The mixed materials additionally had decreased “elongation at break” (i.e. elevated brittleness), however finally the researchers decided that the very best trade-off for utilizing in-situ materials was round a mixture of 60% PEEK and 40% regolith. This combination doesn’t endure from a number of the extra extreme degradation of mechanical properties whereas nonetheless using as a lot native sources as potential.
There may be undoubtedly nonetheless room for enchancment right here, as that is very early on in experimentation with these supplies. Sooner or later, the researchers plan to attempt combining the LRS with completely different polymers, and do extra of their testing / manufacturing in simulated lunar environments, resembling a vacuum and decreased gravity. It is going to be some time earlier than 3D printing makes up a big proportion of the fabric used on the Moon, however that point is definitely on its means, and these first early steps at experimentation are how we are going to finally get there.
Study Extra:
M. Azami et al – Additive Manufacturing of PEEK/Lunar Regolith Composites for Sustainable Lunar Manufacturing
UT – High quality Of 3D Printing With Lunar Regolith Varies Based mostly On Feedstock
UT – 3-D Printing on the Moon. From Regolith to Paste to Helpful Objects and Buildings
UT – NASA Sends a 3D Printer for Lunar Regolith and Extra to the ISS
