Material loss analysis in glass additive manufacturing by laser glass deposition

Abstract

The properties of glass (e.g., transparency, chemical and thermal inertness) are advantageous for optical, microfluidic, and chemical applications. Additive manufacturing allows the creation of complex geometries and novel functionalities. In contrast to metals and polymers, there are limited options for digitally creating transparent glass geometries. Glass becomes viscous when heated above its transition temperature. This allows a bubble-free forming but requires precise thermal management. Previously explored studies established the deposition of multiple types of glasses using fiber and rod feedstocks. A significant challenge is the speed of the process. Phonon modes in all of these glasses directly absorb CO2-laser radiation (λ = 10.6 μm) with an optical penetration depth of <10 μm [J. Bliedtner, H. Müller, and A. Barz, Lasermaterialbearbeitung: Grundlagen–Verfahren–Anwendungen–Beispiele (Carl Hanser Verlag GmbH Co KG, Munich, Germany, 2013), ISBN:3446429298]. The thermal energy must diffuse through the glass with low thermal conductivity to the interface with the workpiece. Faster deposition rates result in the temperature of the process zone exceeding the evaporation temperature for the material and cause material loss. This study quantifies the material loss due to evaporation for the first time and investigates the use of a CO laser (Coherent J-3-5) for the laser glass deposition process. Lower absorption in silica at the 5.5 μm wavelength of this laser permits much deeper optical penetration into the glass. The effects of surface versus volumetric heating resulting from the choice of laser are experimentally investigated by the deposition of glass fibers with different deposition rates with demonstrations of lower vaporization rates under faster deposition conditions.

Investigation of glass bonding and multi-layer deposition during filament-based glass 3D printing

“…In all the cases estimated losses are low, with no vaporization visible during printing or deposited onto the build plate. The low rate of vaporization presented in this work, in comparison to other reports (Sleiman et al, 2021) is ascribed to highly stable and controlled laser heating while using a small hotzone (250-400 µm in diameter), with the required laser power for printing fused silica glass being less than 5.5 W.…”

Rapid Fabrication of Silica Microlens Arrays via Glass 3D Printing

“…The technique is similar to the one, demonstrated previously by Kinzel et al 20–23 The current 3D printer, however, uses four symmetrically placed beams surrounding the glass filament, which was fed perpendicular to the fused quartz plate. Before printing, the protective coating was removed from the filament using mechanical stripping pliers.…”

“…Glass additive manufacturing is an emerging research topic showing an increase in publications in recent years. 20–28 Recent studies demonstrated MLA fabrication in fused silica using two-photon polymerization through a direct laser writing technique, 29 , 30 an approach that combined hot embossing with custom glass 3D printing, 31 stereolithography, 32 and microscale computed axial lithography. 33 These studies were realized by utilizing a new type of silica nanocomposite resin.…”