Non-contact/contact hybrid support based on the slice for ceramic stereolithography

Ceramic stereolithography (CSL) technology can produce parts with complex structures, high precision and excellent mechanical properties. However, to ensure printability, dense and massive contact supports of the suspension part for better performance reduce the surface quality of parts and increase the cost of post-treatment. The shrinkage caused by the photopolymerization of the resin in the slurry and the time asynchrony from the layer-by-layer mode lead to the edge warping of the printed objects. Based on the yield stress of ceramic paste, a new mixed support form combining non-contact support and contact support (NCC) is designed in this paper. The non-contact support and the narrow slurry layer under it provide support for the gravity of the upper part and ensure surface quality. The slight contact support of the boundary is used to limit the curing warpage caused by the resin. What's more, an automatic generation algorithm based on slices for NCC support is designed. The k-neighborhood expansion method is proposed to identify the support demand of each pixel in the slice. The effectiveness of the NCC supports and generation algorithm is proved by the case on the sinking digital light procession (DLP) equipment with alumina ceramic slurry. NCC support can solve the problem of warping while maximizing the surface accuracy, ensuring the stability of printing which represents great industrial value.