The Research On Preparation And Properties Of ZrO₂ Ceramic Ink For 3D Printing

Ink-jet printing technology is one of 3D printing technology. Due to its high printing precision, more attention has been paid to applying it to the manufacture of ceramic materials, especially the preparation of precision ceramic materials. The preparation of ceramic ink is the key of ink-jet printing. For zirconia ceramic, because of its high density, it is difficult to be dispersed stably and difficult to prepare inks with high solid content but low viscosity. According to the principles of colloid chemistry, The paper attempts to add simultaneously two different types of dispersants, ammonium polyacrylate?PAA-NH4? and polyvinylpyrrolidone?PVP?, and change the ratio of deionized water, ethanol and glycerol in solvent to improve dispersion stability of ZrO₂ ceramic ink, thereby a high solid content of 3D printing ceramic ink was prepared by ball-mining method.First, the paper focused on the effects of binary dispersants on the rheology of ceramic ink.The results showed that: The addition mode of binary dispersants had a great influence on the rheology. Compared to the sequential order of addition mode, the viscosity of ceramic inks with the co-addition mode of binary dispersants was smaller. Ceramic ink with the co-addition of 1wt%PAA-NH4 and 1wt%PVP obtained much lower viscosity. SEM results showed that the ceramic ink was dispersed well. According to FITR, the main reason why the viscosity has been improved was that the complexation between PAA-NH4 and PVP may be occurredThen, the stability and drying performance of ceramic inks were evaluated by varying the ratio of and water, glycerol and alcohol in solvent. The results of sedimentation test and drying experiment showed that: The drying rate increased with the increase of alcohol content, Stability is improved with increasing glycerol content. At room temperature, the maximum amount of alcohol is 30vol%, the amount of glycerol added is no more than 35vol%.Finally, the process of ceramic ink-jet printing was observed by droplet observatory. The effects of print temperature, pulse voltage and operating frequency on the droplet ejection behavior were investigated. The results showed that: the homemade ceramic ink had a wide printing temperature range of 25⁶0?; When pulse voltage was controlled at 120 V and operating frequency was 5000 Hz, the droplet morphology ejected from nozzles was better. The denture was printed by the homemade ceramic ink with 20vol% solid content and its sintered density was more than 95% of theoretical density.