Silica moulds built by stereolithography

In this work the production of ceramic moulds for aluminium casting using a stereolithographic apparatus is presented. Suspensions of silica powders in a photoreactive resin were used in standard STL equipment in order to build green parts. UV curable pre-ceramic suspensions have been studied using photocalorimetric and rheological characterizations. Thermogravimetry was used to analyse the behaviour of the pre-ceramic green during thermal treatment. Stereolithgraphy apparatus (SLA) was modified in order to fabricate ceramic green. Silica objects were obtained by pyrolysis of the organic binder and subsequent sintering at high temperature. A characterization of mechanical properties of the green and sintered ceramic materials was performed. Finally moulds for investment casting of aluminium were built by stereolithography and used for casting as a green as well as after sintering.