Multi-material 3D printing of metal-ceramic components for high-vacuum applications.

Multi-material printing is an emerging field in additive manufacturing, offering the ability to produce components with tailored properties by combining different materials. This study focuses on the bi-material printing of 316L stainless steel (metal) and Al₂O₃ (ceramic). The initial phase of the project was dedicated to studying and optimizing the printing processes for both materials to achieve a high-quality final product. Once the printing parameters were defined and the components were successfully produced, the samples underwent a debinding process—both chemical and thermal—followed by sintering. Sintering emerged as the most critical challenge due to the significant difference in sintering temperatures between the two materials, which led to issues such as deformation, cracking, and delamination at the interface. To address these challenges, the second phase of the project focused on the use of sintering aids, such as CuO-TiO₂ and bentonite, added to alumina. The goal of these sintering aids was to lower the sintering temperature of alumina, bringing it closer to that of stainless steel, thereby reducing thermal mismatch and improving the compatibility of the two materials. This work contributes to advancing the understanding of multi-material additive manufacturing, with a focus on overcoming the challenges associated with the integration of metals and ceramics for high-performance applications.