Ceramic injection molding (CIM) is an efficient way to manufacture ceramic components with limited complexity in large quantities [1]. In contrast, additive manufacturing offers enormous design freedom and individualization, but at lower productivity [2]. There are approaches to join ceramic components, e.g. by active metal brazing or adhesives [3]. Usually, this involves auxiliary materials limiting the component properties, for example in terms of strength or applicability at high temperatures [3]. The aim of this research is to join ceramics produced by CIM and the additive manufacturing process vat photopolymerization (VPP) without using function-limiting auxiliary materials. In a first approach, CIM components in their green state are used as inserts and individualized structures are printed on them using VPP. Afterwards, a co-debinding and co-sintering takes place. By varying the CIM feedstock composition and performing mechanical pre-treatments of the CIM green parts, the process is optimized.

In a second approach, the components are designed in terms of a press fit with sufficient offset. The ceramic green parts are manufactured and debinded independently. Subsequently, the inner component is pre-sintered leading to partial shrinkage. This enables a forceless insertion into the outer component. The two components are then co-sintered. Due to the greater shrinkage of the outer component, a press-fit connection is realized. Furthermore, the sintering step is leading at least to a partial material connection between the two sub-bodies. By varying the geometric offset and the sintering parameters, an optimized material connection is achieved. Combining ceramic parts produced by different manufacturing technologies enables a cost-efficient production of complex and individualized components with superior properties.

References:
[1] M. von Witzleben, K. Hajek, D. Raab in W. Kollenberg (Hrsg.) Technische Keramik, 2018, 470-478.
[2] W. Kollenberg Additive Fertigung keramischer Komponenten, 2020, 4-9.
[3] W. Tillmann in W. Kollenberg (Hrsg.) Technische Keramik, 2018, 542-554.