Rapid prototyping of ceramic casting cores for investment casting

The use of ink jet printing technology in the rapid prototyping process has been developed for a number of years, The main problem with the technology is the limitations on the materials that can be formed via this method. This investigation is into the use of ceramic filled inks in the printing process for the manufacture of cores for investment casting. Inkjet printing of ceramics is limited by the requirement of low fluid viscosity this limits the volume fraction of ceramic in suspension that can be jetted through the ink jet nozzle. Here we present a study developing ceramic inks of relatively high solid fraction in suspension. We have studied how properties of the carrier fluid, particle size and surfactant chemistry influence viscosity, surface tension and specific gravity of the suspensions. We have also assessed the suitability of these suspensions for ink-jet printing by using a single jet test station. In order to produce a ceramic object from the printed suspension the carrier fluid must be removed and the final part sintered without loss of shape and detail, Preliminary studies to this end are also reported.