iCAT 2014 Invited lectures

Johannes Homa
Lithoz GmbH, Austria
Lithography-based Ceramic Manufacturing – Additive Manufacturing of High-Performance Ceramics

In the field of ceramic processing there is a strong need for the introduction of Additive Manufacturing (AM) techniques. Tools for powder injection molding (PIM) are very expensive and Rolex Explorer Replica require significant lead times which severely restrict the suitability of PIM for the production of small scale series or customized products; however, no adequate prototyping technology existed so far.

The main reason for that are the high demands on high-performance ceramics – these materials are used where other materials fail, thus the quality and the reliability of the parts are crucial. 

This presentation focuses on a novel AM-approach, which is capable of producing strong, dense and accurate ceramic parts, namely the Lithography-based Ceramic Manufacturing (LCM). It is a slurry-based process, where a photocurable monomer system is mixed with ceramic powder and hardened through mask exposure to give the green body. In this state the generated photopolymer network acts as scaffold and binder for the ceramic particles. This polymer is later on removed at elevated temperatures and the resulting pores are subsequently eliminated during sintering. Thus, this method leads to highly dense ceramics with mechanical characteristics very similar to conventionally formed parts; for alumina a theoretical density of over 99.4 % and 4-point bending strength of over 430 MPa has already been realized.
Moreover, due to its layer-by-layer approach, the LCM-technology provides the opportunity to shape highly complex and intricate geometries that cannot be realized by conventional means. Holes with a diameter of 200 µm and a wall thickness of below 150 µm could be realized by this technology to date. These characteristics render the LCM-technology a capable addition to conventional processing techniques in the field of ceramics.
Dr. Johannes Homa received his master in industrial engineering at the Vienna University of Technology in 2005 and finished his PhD. at the same university in 2008. He is teaching since 2009 at different universities and is co-inventor of three patents. Dr. Homa is the Co-founder and CEO of Lithoz GmbH. Lithoz GmbH is based in Vienna/Austria and is the world leader in additive manufacturing of ceramic components.