Additive manufacturing (AM) is a rapidly developing manufacturing method utilized in fields such as the aerospace industry. In-space AM is a technology of interest for the future of spaceflight, including on-orbit manufacturing. However, AM materials are subject to defects that may impact their performance in space-based applications. How these defects change the material’s reaction to the space environment, specifically atomic oxygen (AO), has only recently been explored. AO is a highly corrosive, dominant constituent in low Earth orbit that causes continuous erosion of spacecraft surfaces. The effect of AO on various AM materials is investigated in this thesis. Stainless steel, aluminum, ULTEM™, and titanium samples made using differing AM techniques were exposed to 24 hours of AO in order to calculate material susceptibility in the form of erosion yield. Additionally, reflectance spectra were collected to detect changes in material at the surface. Over 24 hours, samples were exposed to an average fluence of 9.10 × 1020 atoms cm−2, equating to about 200 times the naturally occurring AO flux at International Space Station altitudes. The statistical significance of effects from AO exposure were determined. Comparisons were drawn between the AM materials tested and conventionally manufactured materials. It was found that mass loss due to AO erosion was significant for ULTEM™, powder bed fusion titanium, and directed energy deposition titanium. The ULTEM™ tested in this thesis had significantly higher erosion yield when compared to ULTEM™ tested by NASA, while all other material comparisons had insufficient evidence to draw similar conclusions. Reflectance spectra did not reveal unexpected differences before and after exposure.
| Identifer | oai:union.ndltd.org:CALPOLY/oai:digitalcommons.calpoly.edu:theses-4496 |
| Date | 01 June 2024 |
| Creators | Grogan, Ryan |
| Publisher | DigitalCommons@CalPoly |
| Source Sets | California Polytechnic State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Master's Theses |
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