1 8 A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y / F E B R U A R Y 2 0 2 3 In conclusion, there is still additional development required for deployment to terrestrial austere environments with this DAR point-of-need manufacturing approach and technology. The maturation of AFSD software needs to include automation of the AM process flow that would be integrated with a digitally driven approach for parameter prediction and optimization through a simulation-based tool framework. However, as the scientific community continues to venture further into outer space, in-situ resource utilization (ISRU) requires that use of secondary feedstocks from jettisoned or damaged launch vehicle components or space debris would be appropriate for DAR as depicted in Fig. 10. Figure 10 shows a fully dense aluminum alloy wrench in the final machined state from a deposition made by recycling strips of scrap aluminum alloy from a NASA collaborative project. This demonstrates the viability of expanding the DAR paradigm for non-terrestrial manufacturing for in-space manufacturing of metallic components from orbital space debris or scrap landers on the lunar surface. Depositions have even demonstrated the viability of incorporating lunar regolith simulant or carbon-based materials with a representative waste aluminum alloy typical to jettisoned lunar landing craft ance and subjected to 4-point bend testing, where the AFSD repaired mat exhibited identical mechanical performance compared to the control mat core. The results in Fig. 9 comparing the new mat base material and the repaired mat core show similar behavior that highlights the benefits of this DAR solid-state, low-heat input, nature of this process for potential in-field repair of components. By taking advantage of depositing the recycled material below the melting point of the material, the repair allows for minimal distortion and minimized loss of strength to the component at the continuum scale. field-portable machine used on an expeditionary airfield for in-field repair at the point-of-need as detailed in Fig. 8. The new edge clamp created in Fig. 8 was fabricated from damaged skins of the airfield landing mats. Since theskinof the landingmatswere thinner than the standardAFSD feedrods, stacks of three matting skin strips were used as the feedstock in the AFSD process. Additionally, to illustrate the use of DAR for repair, an airfield landing mat that sustained a puncture on the landing surface was repaired using the additional damaged landing mat material as feedstock (Fig. 9). The repaired matting was machined back to tolerFig. 8 — Use of AFSD for repairing airfield landing mat components such as edge clamps fabricated frommat core top skins where strips of damaged landing mat built up the component thickness to required sizes. Le image fromRef 26; center image fromRef 27. Fig. 9 — a) Representative 44.5 kN rough terrain forkli used to transport mat bundles[27], b) typical mat bundle configuration[28], c) simulated fork puncture in skin of mat core, (d) as-depositedmaterial (red) and post-deposition machining (blue) to restore original component geometry, and (e) subcomponent four-point bed results depicting similar mechanical behavior between newmat core (base material) and repairedmat core (AFSD repair) cross-sections. The experimental setup and location of the repair is denoted schematically within the graph. The cross-sectional geometry of the component is not publicly available and has therefore been omitted. (a) (b) (c) (d) (e)
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