Stereolitography of ceramic suspensions

The need of fast production of prototypes of complex shapes in very short t ime lead to the development in the last years of many additive rapid protot yping (RP) technologies for the production of single objects or of very lim ited series. The new fabrication concept allowed the construction of comple x parts, starting from a 3D-CAD model, without using a mould. However, most of these additive processes produce polymeric objects and only recently th e laser sintering of metal powders has been commercially introduced. In thi s work the production of ceramic objects by stereolithography is presented starting from the development of UV curable pre-ceramic suspensions for fre e form fabrication of alumino-silicate parts. The suspensions are character ized by 40%-50% by volume of powder content and by a reactivity and a visco sity compatible with their application in stereolithography. The ceramic gr een is built in a stereolithographic system operating with a He-Cd laser (3 25 nm). Then, the ceramic objects are obtained by pyrolisis of the organic binder and subsequent sintering of the green at 1600 degreesC. Finally, a c haracterisation of the mechanical properties and of the microstructure of t he samples is presented. (C) 2001 Kluwer Academic Publishers.