Preparation Of ZTA Ceramic Powder By Spray Grying And Study On The Density Of ZTA Ceramic

With Al?NO₃?₃·9H₂O and Zr OCl₂·8H₂O as raw material,spray drying-calcining preparation of nano ZrO₂/Al₂O₃ ceramic composite powder with good sinterability,Then molded and sintered.Study of preparation process of optimized process parameters and influence of sintering factors.The addition of TiO₂ sintering agent on its effect on the microstructure and mechanical properties were studied,and draw the following conclusions:?1?With Al?NO₃?₃·9H₂O and ZrOCl₂·8H₂O as raw material preparation of the solution,sucrose spray drying ZTA precursor powder and then heat-treated after calcination prepared ZrO₂/Al₂O₃ composite powders.The study found that after spray drying of 200? and calcination treatment of 1200?,ZrO₂ mainly in the tetragonal form,appears sharp diffraction peak,Al₂O₃ existed with ?-Al₂O₃ stable;sucrose carbon source during calcination generated CO ? CO₂ produced on aggregate expansion to fracture,thereby obtaining a desired particle size of the powder,the particle size analysis showed that the ZrO₂ particle size of about 25 nm,Al₂O₃ particle size are within 5?m,and prepared powders on electron microscopy can be found in well-dispersed,evenly distributed in two phases;?2?Gelcasting and pressureless sintering ZrO₂/Al₂O₃ composite powder,the sintering temperature is 1550 ?,the sintered body dense structure,ZrO₂ evenly distributed in the matrix and Al₂O₃ intergranular crystal.Discover the test,the overall performance of the best sintered1550?,density reached 97.8%,a bending strength of 380 Mpa;?3?Different amounts of TiO₂ impact on the ceramic microstructure and density,quite different mechanical properties.When added 0.5wt%of TiO₂,it can be dissolved in in the matrix of Al₂O₃ and Zr O₂ solid solution,promoting ZTA at a lower temperature sintering densification.Flexural strength of ZTA add 0.5wt% TiO₂ basically in400MPa⁵00MPa,hardness reached 1710 GPa,fracture toughness is 6.4Mpa·m1/2;When added 1wt% TiO₂,ZTA can be sintered at a low temperature,but the resulting ZrTiO4 impurity phase reduce the material properties.When the proper amount of TiO₂,ZTA is stable at roomtemperature to increase the content of t-ZrO₂,ZTA toughness.