Study Of DLP Forming And Properties Of Zirconia Ceramics

Zirconia（ZrO₂）is widely used in various fields due to its excellent mechanical properties,high-temperature insulation,and biocompatibility,among other advantages such as high melting point,high hardness,chemical resistance,and wear resistance.3D printing technology,as a rapid prototyping technique,constructs a three-dimensional model of an object or part using computer software and adds selected materials point-by-point,line-by-line,or layer-by-layer,ultimately building a three-dimensional solid part.Ceramic photopolymerization printing technology uses photo-curable resins to fix ceramic particles in a matrix under ultraviolet light,obtaining specific-shaped ceramic green bodies by layer-wise accumulation through area projection or line projection,with the advantages of high accuracy,the ability to fabricate complex structures,rapid prototyping,and large-scale preparation.The printed ceramic green body can be obtained with complete shape and excellent mechanical properties through drying,debinding,sintering,and other processes.In this study,the effect of adjusting the resin proportion,solid phase content,and dispersant content in ceramic slurry formulations on the rheological properties of the slurry was investigated.When the ratio of polyethylene glycol diacrylate to 1,6-hexanediol diacrylate was 1:5,the resin showed low fluidity and relatively excellent shrinkage.The effect of different solid phase contents on viscosity was investigated,and it was found that when the solid phase content was 40%,the viscosity reached 8230m Pa·s,with poor fluidity and almost inappropriate for printing.The effect of dispersant content on viscosity was studied,and it was found that after adding 10%of BYK-104,the viscosity of the slurry significantly decreased,and at a shear rate of 1/40 s,the viscosity dropped to 3933.2 m Pa·s,meeting the basic requirements of ceramic printing.Suitable printing parameters were obtained by studying the effect of curing power and curing time on printing effects.The results showed that curing power and curing time had a consistent influence on curing effect.With the increase of curing power and curing time,the curing thickness increased significantly,but the curing accuracy decreased.At a curing power of 30 m W/cm² and a curing time of 10 s,the overall curing effect was good,with a printed slice thickness of about 125μm and an accuracy of less than 100μm,successfully printing high-precision complex models.After debinding,the printed samples were sintered at 1500℃for 4 h to obtain dense zirconia ceramics with shrinkage rates of 25.39%,26.47%,and 26.52%in the X,Y,and Z directions,respectively,and a density of approximately 97%±0.52.Three-point bending tests were performed on the printed standard bars,with bending strength reaching 711.18 MPa.Microscopic analysis of the fracture surface showed that the printed part was dense internally,with transgranular fracture.High-precision printing and microscopic analysis of various models such as screws and teeth confirmed the high fidelity and accuracy of the printing method.The results demonstrate the successful preparation of zirconia ceramics by DLP photopolymerization printing and their excellent performance.