Eliminate anisotropy by vacuum impregnating 3D printed porous alumina with Yttrium solutions

DLP technology shows great potential in the complex forming of high-precision ceramic materials. However, the layer-by-layer manufacturing method inevitably leads to microstructure defects. In this study, three yttrium-containing solutions (Y(NO3)3, YCl3, standard yttrium solution) with different contents are used to study the effect of vacuum impregnation on the properties of DLP printed alumina ceramics with high porosity. Samples with high strength and high porosity without layered structure were successfully obtained. The effects of three yttrium-containing solutions on flexural strength and contraction anisotropy of samples were compared, which provided a method and reference for eliminating anisotropy of 3D printed ceramics. The Y(NO3)3 solution has a better effect and its concentration can be further increased. Therefore, its application is the first choice. When the concentration of Y(NO3)3 solution is 0.030 mol/L, the impregnated alumina sample has a flexural strength of 36.02 ± 0.84 MPa, an open porosity of 45.32 %.