Degreasing process of thick-walled alumina ceramics based on vat photopolymerization

Vat photopolymerization can achieve high precision, low cost and rapid manufacturing of ceramic parts. However, it is challenging to prepare thick-walled ceramic components (thickness >= 7 mm) since the violent decomposition of resin during degreasing process always leads to formation of cracks when the solid wall thickness is larger than 7 mm. In order to avoid the formation of cracks, the degreasing mechanism of ceramic is investigated systematically. Based on the experimental results under different degreasing conditions, the degreasing accumulation model is established. In order to increase the ultimate thickness of ceramics, the influence of plasticizer on the degreasing behavior is explored. The results show that the plasticizer can shift decomposition of resin to lower temperature range and enable the formation of pores during decomposition. These pores could work as channels for the evaporation of decomposition products of the resin and avoid cracking between the interlayers. Finally, the thick-walled samples (thickness = 15 mm) with cracks free are degreased in this work.