Textured Porous Al₂O₃-SiO₂ Composite Ceramic Platelet-sphere Slurry: Characteristics and Simulation of Light Intensity Distribution

Ceramic stereolithography has a broad prospect in the preparation of Al2O3-SiO2 composite ceramics.The textured Al2O3-SiO2 composite preparation through ceramic stereolithography still need to be investigated.In this paper, we investigated the characteristics of ceramic slurries with addition of alumina platelet, equiaxed alumina, and spherical silica.A comparative analysis of the viscosity, sedimentation, curing characteristics, curing accuracy of the slurries with different solid content was carried out.An ultraviolet (UV) light intensity distribution simulation algorithm was developed, and the theoretical simulation analysis of the light intensity distribution in the slurry during exposure process was carried out.The textured porous Al2O3-SiO2 composite with the characteristics of oriented alumina platelet was successfully prepared.The results showed that the combination of alumina platelet with spherical powders allowed the slurry to maintain low viscosity and shear shinning behavior athigh solid content (40%-45% total solid content, alumina platelet accounted for 50%-60% of the total solid content).At the same total solid content, increasing the amount of alumina platelet or increasing the amount of spherical silica could reduce the viscosity of the slurry, while increase the sedimentation of the slurry.Alumina platelet reduced the blocking and scattering effect of UV light in the slurry compared to equiaxed alumina.Under the same exposure energy condition, decreasing the content of the equiaxed alumina and increasing the spherical silica could increase the curing thickness of the slurry, while increasing the content of platelet alumina and spherical silica led to an increase in dimensional error.Numerical simulation results showed that alumina platelet with near horizontal distribution had week effect on UV light blocking and deflection, and alumina platelet with near vertical distribution had guiding effect on UV light.The variation of the mean UV intensity at the upper boundary of the model were close to the variation of the curing thickness.The established model can provide theoretical support for the experimental test results of the curing thickness.