Tuning the 3D Printability and Thermomechanical Properties of Radiation Shields

Abstract

Additive manufacturing, with its rapid advances in materials science, allows for researchers and companies to have the ability to create novel formulations and final parts that would have been difficult or near impossible to fabricate with traditional manufacturing methods. One such 3D printing technology, direct ink writing, is especially advantageous in fields requiring customizable parts with high amounts of functional fillers. Nuclear technology is a prime example of a field that necessitates new material design with regard to unique parts that also provide radiation shielding. Indeed, much effort has been focused on developing new rigid radiation shielding components, but DIW remains a less explored technology with a lot of potential for nuclear applications. In this study, DIW formulations that can behave as radiation shields were developed and were printed with varying amounts of porosity to tune the thermomechanical performance.

Balancing Functionality and Printability: High-Loading Polymer Resins for Direct Ink Writing

“…The inks created in this study consist of a siloxane and fumed silica base similar to that of Brounstein et al [ 19 ]. Siloxanes used in this study include vinyl-terminated (4–6% diphenylsiloxane)-dimethylsiloxane copolymer (Gelest PDV-541) and trimethylsiloxy-terminated methylhydrosiloxane-dimethylsiloxane copolymer (Gelest HMS-301) (Gelest, Inc., Morrisville, PA, USA).…”

“…This can be a tricky endeavor since the foundations of most 3D printing feedstocks are polymers, while the added functional materials are usually metals, ceramics, or other powders that may detract from optimal mechanical properties like flexibility, flow, and tensile strength that make the polymers ideal materials for 3D printing feedstock [ 17 , 18 ]. For DIW printing in particular, adding functional fillers to polydimethylsiloxane (PDMS)-based inks can result in nozzle clogs, discontinuous flow onto the print bed, and increased sagging in areas of a print where bridging occurs leading to deviations in desired print dimensions [ 18 , 19 ]. The ability of an ink to create an object accurately and precisely as determined by the print code will be referred to as “printability”.…”

“…Previous work by this group has examined the relationship between single metallic and ceramic filler concentrations up to 50 wt%, or multi-filler concentrations up to 70 wt%, and the resulting printability and mechanical properties of face-centered tetragonal (FCT) or square-centered (SC) lattice structures [ 18 , 19 ]. This study builds upon previous work and analyzes the printability limits and thermomechanical characteristics of DIW inks containing 50–70 wt% metallic and ceramic fillers printed in FCT and SC lattice geometries.…”

Composites Additive Manufacturing for Space Applications: A Review

“…One of the PEI product family is the ULTEM TM series; for example, ULTEM 9085 is amenable to 3D printing because its flow property is enhanced by incorporating the PC The FDM/FFF method and the light-curing approach mentioned in Section 2.1 (Heat Shields for Suborbital Flight), required the heat source and filament materials. Direct ink writing (DIW) is another interesting approach that can broaden the material and geometry choices with a variety of curing methods: ultraviolet, elevated temperature, and freeze drying to name a few [43]. Dimethylpolysiloxane (also called polydimethylsiloxane, (PDMS), [−Si(CH 3 ) 2 O−] n ), for example, exhibits neutron shielding properties after DIW using fillers such as boron, tungsten, tungsten (VI) oxide, or/and gadolinium (III) oxide.…”

3D Printed Chromophoric Sensors

“…Indeed, the facile ability to combine metals, ceramics, glasses, functionalized particles, and/or biomolecules into Sylgard 184 and develop distinct layers that can contain heterogeneous fillers makes it an incredibly versatile and popular polymeric system. Our team has previously worked on aspects of this, where composites were made using different types of Sylgard or siloxanes and fillers to alter the surface adhesion and thermomechanical properties [18,19].…”