Bubble Formation in Additive Manufacturing of Glass
Bubble formation is a common problem in glass manufacturing. The spatial density of bubbles in a piece of glass is a key limiting factor to the optical quality of the glass. Bubble formation is also a common problem in additive manufacturing, leading to anisotropic material properties. In glass Additive Manufacturing (AM) two separate types of bubbles have been observed: a foam layer caused by the reboil of the glass melt and a periodic pattern of bubbles which appears to be unique to glass additive manufacturing. This paper presents a series of studies to relate the periodicity of bubble formation to part scan speed, laser power, and filament feed rate. These experiments suggest that bubbles are formed by the reboil phenomena why periodic bubbles result from air being trapped between the glass filament and the substrate. Reboil can be detected using spectroscopy and avoided by minimizing the laser power while periodic bubbles can be avoided by a two-step laser melting process to first establish good contact between the filament and substrate before reflowing the track with higher laser power.
J. Luo et al., "Bubble Formation in Additive Manufacturing of Glass," Proceedings of SPIE, Advanced Optics for Defense Applications: UV through LWIR (2016, Baltimore, MD), vol. 9822, SPIE, Apr 2016.
The definitive version is available at https://doi.org/10.1117/12.2224321
SPIE Defense + Security 2016 (2016: Apr. 17-19, Baltimore, MD)
Mechanical and Aerospace Engineering
Intelligent Systems Center
Keywords and Phrases
3D printers; Bubble formation; Glass; Glass manufacture; Manufacture; Anisotropic material properties; Foam layers; Glass-manufacturing; Laser melting process; Laser process; Optical qualities; Periodic pattern; Spatial densities; Optical glass; Additive Manufacturing; Laser processing
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Article - Conference proceedings
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