Evaluation of Stereolithography-Based Additive Manufacturing Technology for BaTiO3 Ceramics at 465 nm

Featured Application Efficient 3D-printing of lead-free piezoceramic items using stereolithography-based additive manufacturing procedure. A piezoceramic BaTiO3 material that is difficult for 3D printing was tested with a homemade laser-based stereolithography (SLA) setup. The high light absorbance of BaTiO3 in the spectral range of 350-410 nm makes this material hardly usable with most commercial SLA 3D printers. The typical polymerization depth of BaTiO3 ceramic pastes in this spectral range hardly reaches 30-50 mu m for 40 vol % powder loading. A spectral change to 465 nm was realized in this work via a robot-based experimental SLA setup to improve the 3D printing efficiency. The ceramic paste was prepared from a preconditioned commercial BaTiO3 powder and used for 3D printing. The paste's polymerization was investigated with variation of powder fraction (10-55 vol %), speed of a laser beam (1-10 mm/s, at constant laser power), and a hatching spacing (100-1000 mu m). The polymerization depths of over 100 mu m were routinely reached with the 465 nm SLA for pastes having 55 vol % powder loading. The spectral shift from 350-410 nm spectral region to 465 nm reduced the light absorption by BaTiO3 and remedied the photopolymerization process, emphasizing the importance of comprehensive optical analysis of prospective powders in SLA technology. Two multi-layered objects were 3D-printed to demonstrate the positive effect of the spectral shift.