Christian A. Rottmair

Powder Injection Moulding (PIM) of Mesophase Carbon with Water-Based Binders

Since there are no net-shape techniques for complex parts made of mesophase carbon available yet, this work focuses on a powder injection moulding (PIM) approach. The single biggest problem to overcome here is the overlap of debindering and pyrolysis/sintering of mesocarbon when using conventional binders, causing high porosity and cracks. Water-based binders with agar as gelling agent can avoid this problem effectively by removing the binder in an optimized drying step. The subsequent sintering can then be carried out at high heating rates, leading to better densification and good mechanical properties. Furthermore, the dependency of the rheological properties of the water-based feedstock on its water content is investigated.

Influence of Pressure and Heating Rate on the Mechanical Properties of Mesophase Based Sintered Parts

This work focuses on the influence of different sintering parameters on the mechanical properties of pressed and sintered mesophase based parts. In a first approach we analyzed the influence of the heating rate on the sintering process and in subsequent experiments we applied inert gas pressure up to 1000 bar.