The Use of Metallized Stereolithography Additively Manufactured Components in Space

Stereolithography additive manufacturing (SLA) is a process through which three-dimensional parts are constructed layer-by-layer in two-dimensional slices by selectively curing a UV resin. When compared with other additive manufacturing (AM) processes, SLA is benign with low temperatures and minimal build forces. This allows complex, high-resolution parts to be built with tolerances that rival or exceed conventional machining. As with most AM processes, small and complex features can be added with negligible additional cost or difficulty. The final parts are typically made of polymers, however, which limits their usefulness in structural and electronic applications and adds additional concerns for space applications regarding material properties, long-term stability, and outgassing. To improve the usefulness of components made via SLA, this paper discusses the use of a metallized layer on the outside of the polymer component to improve strength, provide protection, and allow electrical conductivity. This work first gives background into the SLA manufacturing and metallization methods with an overview of each process. This is followed by a discussion of the design variables and engineering considerations relating to metallized SLA, presenting many of the degrees of freedom that may be optimized to tailor the component for a specific application and improve results. An experimental test part is then presented that includes a number of primitive shapes commonly used to create larger mechanical components. The size and depth of these features is varied in an effort to determine the limits of the fabrication and plating processes as they relate to part geometry. Four of these components were fabricated and plated with differing metal layers. Optical and computed tomography (CT) inspections were employed to determine the consistency and thickness of the coatings, the results of which are presented. This manufacturing technique is being explored to fabricate a complex filter plate for the upcoming Experiment for Space Radiation Analysis (ESRA) Wide Field of View Plasma Spectrometer (WPS) instrument. The design decisions, environmental testing, and destructive inspection results are presented. This paper concludes by discussing ongoing work and future applications for this manufacturing technique.