Erosion resistance and durability improvement of polymers and composites in space environment by ion implantation

Abstract

Spacecraft designers use polymers and polymer-based composite materials extensively in electrical, thermal, and structural applications to address both weight and performance demands. Without protection from the deleterious effects of the space environment, in particular hyperthermal atomic oxygen (HAO), these materials suffer accelerated erosion from chemical interaction and experience a loss of mass and deterioration of performance. High dose implantation at energies in the 10–100 keV range using ions of metal or semiconductor materials was used as a method of modifying the surface of these polymeric materials to produce changes that can yield dramatic improvements in space environmental durability. The results of this study show that computer modelling of the ion implantation process combined with reasonable fluence estimates give a good basis for the choice of implantation conditions. This study presents the results for high-performance materials including Kapton ®, Mylar ®, PEEK, Lexan ®, and PEEK/carbon fibre composites using X-ray electron spectroscopy, scanning electron microscopy, and other surface analysis techniques, before and after treatment. The results show that implantation of silicon and aluminum (singly, binary, or in combination with boron) or yttrium implantation produces a stable, protective oxide-based layer following exposure to HAO. The improvement in chemical resistance of these materials assures performance without deterioration in long duration space missions and shows promise for improvement in terrestrial performance in highly reactive oxidative environments.