3D printing of preceramic polymers toward carbide-type ceramic pieces – PDCs-3D

Stereolithography is a powder-based layer-by-layer process that is restricted to a small number of compositions; mainly oxide-type ceramics such as hydroxyapatite (for biomedical applications as well as alumina and zirconia (for electronic applications)). This process offers printing of ceramics by selective curing of a photosensitive resin that contains the ceramic particles followed by heat-treatments to form the dense objects with complex shapes, high dimensional resolution, good surface state and properties that equal those of the same materials prepared by conventional processes. Stereolithography is restricted to a small number of compositions because of the UV absorption of some ceramic particles such as silicon carbide (SiC). Therefore, it is not possible to prepare SiC-based objects by stereolithography whereas this material is highly strategic in the military and civil domains. One solution consists to use preceramic polymers as SiC precursors instead of ceramic powders. By entering the scope of the topic « Material, chemistry and energy » of the ASTRID call and especially the sub-topic 6.6.1 « Material », the PDCs-3D project proposes to combine the stereolithography process and the Polymer-Derived Ceramics (PDCs) route to form SiC-based objects derived from preceramic polymers in which the photo-sensitive function has been added at molecular scale and active fillers are homogeneously distributed. This combination is expected to offer a fine control of the stoichiometry of the elements and micro-/nanostructure in the final materials while generating complex shapes of ceramics with a limited volume shrinkage. Therefore, the objective of the PDCs-3D project is to develop a new generation of SiC-based ceramic objects including SiC and its (nano)composite derivatives B4C/SiC, TiC/SiC et AlN/SiC displaying thermomechanical properties and oxidation resistance and more specific properties such as electrical properties, diffusivity and optical selectivity. The three-year PDCs-3D research project brings together specialists in polymer synthesis and characterization, rheology, stereolithography, heat-treatments and materials characterization coming from one partner, the Institute of Research on Ceramics (IRCER, Limoges). To reach our objectives, the project is based on preliminary results already obtained on the polymer-to-ceramic conversion of the targeted systems by IRCER. PDCs-3D is subdivided into four interconnected scientific tasks going from the synthesis and rheological characterisation of active filler-containing photosensitive preceramic polymers with tuned chemistry to the characterization of the final ceramics as powders and objects made by stereolithography. The present project is built to elaborate materials that are expected to find interests in the military and civil domains such as for example structural materials. It should lead to benefits for the advancement of science, industry and society and should allow France to be in place on this growing thematic at international scale.