Present state of 3D printing from glass

This paper deals with the issue of additive technologies using glass. At the beginning, our research dealt with a review of the current state and specification of potentially interesting methods and solutions. At present, this technology is being actively developed and studied in glass research. However, as the project started at the Department of Glass Producing Machines and Robotics, the following text will be more focused on the existing 3D printing machinery and basic technological approaches. Although “additive manufacturing” in the sense of adding materials has been used in glass manufacturing since the beginning of the production of glass by humans, the term additive manufacturing nowadays refers to 3D printing. Currently, there are several approaches to 3D printing of glass that have various outstanding advantages, but also several serious limitations. The resulting products very often have a high degree of shrinkage and rounding (after sintering), and specific shape structures (after the application in layers), but they generally have a large number of defects (especially bubbles or crystallization issues). Some technologies do not lead to the production of transparent glass and, therefore, its optical properties are significantly restricted. So far, the additive manufacturing of glass do not produce goods that are price competitive to goods produced by conventional glass-making technologies. If 3D glass printing is to be successful as an industrial and/or highly aesthetically valuable method, then it must bring new and otherwise unachievable features and properties, as with 3D printing of plastic, metal, or ceramics. Nowadays, these technologies promise to be such a tool and are beginning to attract more and more interest.

Structure and spectral properties of Fe:ZnAl2O4 transparent glass-ceramics and ceramic

Transparent glass-ceramics based on iron-doped ZnAl2O4 (gahnite) nanocrystals were prepared by melt-quenching (at 1580 °C) with subsequent heat-treatments (at 720 – 1050 °C). Polycrystalline transparent Fe:ZnAl2O4 ceramic was synthesized by hot pressing of powders (at 1600 °C, 50 MPa) using the sintering additive, ZnF2. A comparative study of the structure, Raman spectra and absorption properties of these materials was performed.

Lithium aluminosilicate glass-ceramics for low-temperature anodic sealing of MEMS sensors

The results of a study of the anodic bonding parameters of transparent glass-ceramics based on lithium aluminosilicates which are promising as structural materials of MEMS and MOEMS sensors are presented. A comparison of the optical transmittance of these materials and classical for MEMS industry glasses has been carried out. The glass-ceramics electrical conductivity in a wide temperature range has been measured. The procedure of hermetic sealing of glass-ceramics by the anodic bonding at temperatures of 150 – 250 °C has been worked out. A prototype of glass-ceramic atomic cell has been fabricated.