Effects of the Layer Height and Exposure Energy on the Lateral Resolution of Zirconia Parts Printed by Lithography-Based Additive Manufacturing

oleh: Laura Conti, Daniel Bienenstein, Mario Borlaf, Thomas Graule

Format: Article
Diterbitkan: MDPI AG 2020-03-01

Deskripsi

Lithography-based ceramics manufacturing (LCM) processes enable the sophisticated 3 dimensional (3D) shaping of ceramics by additive manufacturing (AM). The build-up occurs, like many other AM processes, layer by layer, and is initiated by light. The built-in digital mirror device (DMD) enables the specific exposure of desired pixels for every layer, giving as a consequence a first estimation of the printing resolution in the x and y axes. In this work, a commercial zirconia slurry and the CeraFab 7500, both from Lithoz GmbH (Vienna, Austria), were used to investigate the potential of reaching this resolution. The results showed that the precision of a part is strongly dependent on the applied exposure energy. Higher exposure energies resulted in oversized dimensions of a part, whereas too low energy was not able to guarantee the formation of a stable part. Furthermore, the investigation of the layer thickness showed that the applied exposure energy (mJ/cm<sup>2</sup>) was acting in a volume, and the impact is visible in x, y, and z dimensions. The lowest applied exposure energy was 83 mJ/cm<sup>2</sup> and showed the most accurate results for a layer thickness of 25 &#956;m. With this energy, holes and gaps smaller than 500 &#956;m could be printed; however, the measurements differed significantly from the dimensions defined in the design. Holes and gaps larger than 500 &#956;m showed deviations smaller than 50 &#956;m from the design and could be printed reliably. The thinnest printable gaps were between 100 and 200 &#956;m. Concerning the wall thickness, the experiments were conducted to a height of 1 cm. Taking into account the stability and deformation of the walls as well, the best results after sintering were achieved with thicknesses of 200&#8722;300 &#956;m.