Effect of solid loading on properties of zirconia ceramic by direct ink writing

High solid loading water-based zirconia slurries for direct ink writing had been successfully prepared in this paper. The water-soluble epoxy resin and sodium polyacrylate were used as the binder and dispersant, respectively. The effect of solid loading on the rheological properties of zirconia slurries was systematically investigated. The 54-58 vol.% zirconia slurries exhibited suitable printability for direct ink writing. After sintering at 1550 °C for 2 h, the properties of sintered zirconia ceramic specimens including linear shrinkage, relative density, flexural strength, tensile strength and microstructure were examined by a series of test methods. Further, the intrinsic relationships between the solid loading and physical and mechanical properties of zirconia ceramic specimens were explored. The experimental results showed that the densification and strength of sintered zirconia ceramic could be significantly improved by increasing the solid loading of zirconia due to the less content of organic matter and water. The maximum relative density, flexural strength and tensile strength of the sintered specimens were 98.8% ,676 10 MPa and 92 5 MPa, respectively, when the zirconia solid loading was 58 vol.%.