Period: 1.2021 – 12.2022

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Dr. Jurij Koruza
FG Nichtmetallisch-Anorganische Werkstoffe (NAW)
FB Material- und Geowissenschaften

Prof. Dr.-Ing. Matthias Weigold
Institut für Produktionsmanagement, Technologie und Werkzeugmaschinen
(PTW) FB Maschinenbau

Stefan Mischliwski
Institut für Produktionsmanagement, Technologie und Werkzeugmaschinen
(PTW) FB Maschinenbau

Lovro Fulanović
FG Nichtmetallisch-Anorganische Werkstoffe (NAW)
FB Material- und Geowissenschaften

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Project description:

AblPie serves the future sustainable production of piezoceramics. By avoiding lead as an ingredient at an early stage, highly toxic hazardous waste is avoided and a foreseeable ban is anticipated, thus positioning TUDa for necessary research priorities in the future.

To this end, several lead-free piezoceramic powders for high-frequency applications were produced in the project. For additive manufacturing using LCD processes, these powders were further processed with a liquid monomer to form a suspension (slurry). Effects such as agglomeration and sedimentation were observed. To minimize these effects, the particle sizes and distribution were systematically modified. Since the additive LCD process is based on light curing by UV light, the slurry was photosensitized in the next step. For this purpose, the liquid monomer was replaced by a photopolymer and a photoinitiator was added. The material property viscosity, which is central to the additive process, was adjusted by the targeted addition of a dispersing agent.

For test series on polymerization, slurries with different ceramic powder concentrations (20%, 30%, 40%) were used in a light polymerization unit with a known wavelength distribution and temperature environment. Here, insights into oxygen diffusion at the surfaces and a related evaporation of the monomer could be obtained. A debinding and sintering process was designed and carried out for the test specimens produced. The challenge of the delamination effect (the detachment of individually applied layers) could not be overcome. The resulting components were ultimately examined for their characteristic electrical values and compared with conventionally manufactured components.

In the area of machine production, the process could not be finally developed. Further investigations are required for this purpose.

Based on these project results, these publications are currently being published:

• Suspensions for additive manufacturing of lead-free NBT-BT piezoceramics using digital light processing

(in Progress).

Double FIF-Success of Materials Science

Im Rahmen des Projektes entstand die Bachelorthesis von Yue Liu mit dem Titel „Additive Fertigung von 0,94(Na0,5Bi0,5)TiO3-0,06BaTiO3 via Stereolithographie“. Die Thesis wurde 2021 erfolgreich abgeschlossen und wird derzeit, ergänzend durch weitere Projektergebnisse, veröffentlicht:

Lovro Fulanovic, Yue Liu, Stefan Mischliwski, Jurij Koruza, Suspensions for additive manufacturing of lead-free NBT-BT piezoceramics using digital light processing, (in Progress) (2022).