Design of Supports to Avoid Deformations in the Process of Alumina Printing by Stereolithography

Abstract

The excellent properties of ceramic materials make them essential for fields such as aeronautic, biomedical, dental, jewelry or electronic. However, the main drawback when manufacturing parts with these materials is their high brittleness. Additive manufacturing processes for ceramic materials allow this limitation to be overcame. Nevertheless, the required stages for additive manufacturing of ceramic parts make the process extremely difficult and with significant influence on the dimensional and geometrical precision.The stereolithography additive process for ceramic is similar to the conventional polymeric process, excepting that the raw material is a slurry of ceramic particles mixed with photosensitive resins. Consequently, two thermal post-processes are necessary to obtaining the final part: (i) debinding and (ii) sintering. Each of the stages in the process is critical because deformation, cracks or fractures can happen, mainly due to temperature changes during the post-processes. Consequently, a deep study of the stages of printing, debinding and sintering is necessary for optimizing them and to produce high-quality parts.In this work, two different types of supports have been studied to prevent deformations during the printing stage. Despite the great importance of supports in this additive manufacturing process, scarce information is available about their design beyond very general recommendations. This paper contains a preliminary study that reveals the effectiveness of using adequate supports to avoid deformations in the printing process. Parts have been scanned with a 3D structured light scanner and the obtained meshes compared with the nominal CAD. This comparison has revealed deformations during the sintering process; therefore, the need to extend the study of support design to the post-processing stages. Future work is necessary to extend this preliminary analysis of support design to improve the quality of SLA ceramic parts with different shape and size.