Investigations on the production and forming of thermoplastic ceramic green tapes

Technical ceramics such as alumina with its temperature stability, high mechanical stiffness, and good dielectric strength at low density, meet the requirements for highly resilient components for promising markets of high-performance electronics and the electrification of mobility. Ceramic components are usually manufactured using powder technology processes since forming of sintered ceramics is not possible due to the lack of plasticity. In this work, we use hydroforming to shape thermoplastic ceramic green tapes prior to sintering to add a third dimension to flat substrates. We developed alumina feedstocks based on a polyamide binder system that were extruded to 1 mm thick tapes, hydroformed, debinded and sintered. Depending on the binder composition, forming temperatures of 45-60 degrees C were sufficient, whereby precise temperature control was crucial for success. As a result, components with forming depths of up to 5 mm were produced without defects. This process offers the potential to revolutionize this market segment, not only in terms of geometric design freedom and low material waste, but also in terms of profitability of mass production.