Properties of Al₂O₃ Ceramic Microspheres Prepared by Micro-droplet Jetting Rapid Forming

Abstract

To rapidly prepare the alumina ceramic microspheres with control of particle size, a ceramic microsphere rapid forming equipment based on droplet jetting technology and slurry curing technology was designed. The Al2O3 microspheres were prepared by using the rapid forming device with alumina powder as raw material, polyvinyl alcohol (PVA) as a binder and boric acid as a curing agent. The effect of different slurry composition parameters on the formability of green body was investigated. The effect of nozzle diameter and slurry extrusion pressure on the particle size of Al2O3 microspheres was studied. The effect of sintering temperature on the properties of Al2O3 microspheres was analyzed and compared. The results show that when the mass fraction of alumina powder, PVA and boric acid are respectively 70%, 3% and 10%, the green body of Al2O3 microspheres have high sphericity and better formability. The controllability of the particle size distribution can be achieved by adjusting nozzle size and slurry extrusion pressure. Ceramic microspheres possess the best comprehensive property, when sintered at 1400℃, the particle size of Al2O3 microspheres is uniform, the sphericity is about 1.08, the porosity is 43.7%, the relative density is 82.1%, and the crush load is up to 76.5N.

Keywords

• droplet jetting technology
• ceramic microspheres
• alumina
• sphericity
• size distribution