Investigation of effects induced by 57 MeV 56Fe ions and 9 MeV protons on additively manufactured PEKK for space application

Abstract

Additive manufacturing (AM) has progressed from rapid prototyping to rapid manufacturing of equipment for various industries, including the space industry, where polymer-based techniques like Material extrusion (MEX) are particularly interesting. Polyetherimide (PEI), Poly ether ether ketone (PEEK) and Poly ether ketone ketone (PEKK) are frequently chosen to manufacture end use equipment in MEX due to their desirable properties. Although some previous studies analysed the effects of protons, electrons, and UV, less is known about the effects of heavy ions from galactic cosmic rays (GCR) and solar particle events (SPE) on these polymers. This study investigated the effects of heavy ions from GCR and SPE on chemical (X-Ray photoelectron spectroscopy and FT-IR spectroscopy), surface (SEM-EDS), and micromechanical (nanoindentation) properties of PEKK. To achieve this, SPENVIS simulations were performed to quantify the fluences of protons and heavy ions experienced by satellites on orbit and the calculated fluences of ions were then implanted on PEKK to emulate space-like conditions for the first time in literature. MEX printed PEKK samples were irradiated with 57 MeV 56Fe ions to achieve absorbed doses up to of 80 Gy, representative of the total dose to which satellites are exposed throughout their transport and time in orbit and up to 200 times more. The chemical, surface, and mechanical properties of the PEKK samples were analysed both before and after irradiation. Results showed no significant changes in properties, indicating that PEKK has potential structural applications in long-duration space missions. This suggests that PEKK can withstand the harsh conditions in space and may offer a viable alternative to traditional metals.