Effect of ternary particles size distribution on rheology of slurry and microstructure of DLP printed ZTA ceramic

Abstract

The effect of ternary Al2O3 particles size distribution on rheology of ceramic paste, microstructure and mechanical properties of printed ceramics was studied. An optimum proportion formula for ternary particles was derived and the UV curable ceramic slurry containing 67.5 vol% of coarse, 22.5 vol% of medium and 10 vol% of fine particles possessed the minimum porosity of 32.64% and presented the lowest viscosity. The ceramic slurry with solid loading of 50 vol% and viscosity less than 20 000 mPa s was prepared and a fitting equation was proposed to indicate the relevance between the viscosity and the ternary components. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) were used to determine the role of size distribution and ZrO2 content on the phase composition and microstructure. The ZTA ceramics containing 25 vol% ZrO2 and ternary Al2O3 particles were sintered and the linear shrinkage was less than 20%, and the highest compressive strength, fracture toughness, Vickers hardness and relative density were 781 ± 39 MPa, 3.76 ± 0.05 MPam1/2, 19.58 ± 0.33 GPa and up to 99.3%.