Synthesis of Calcium Phosphate-Mullite Composite Powders by Ultrasonic Spray Pyrolysis and The Sintering Properties

Abstract

Fine particles of hydroxyapatite (HAP) and tricalcium phosphate (TCP) doped with spherical mullite particles, where the ratio of Ca/P was 5:3 and 3:2, were prepared by spray pyrolysis using an ultrasonic atomizer. As-prepared powders, which were sub-micron in size with a narrow size distribution, were dense and non-agglomerated particles. The effects of concentration, pyrolysis temperature, and flow rate on particle size, particle size distribution, and crystal phase were investigated. The relative density of HAP sintered at 1523K and TCP sintered at 1373K was about 93% and 99%, respectively. The mechanical properties of mullite-doped HAP and TCP ceramics were investigated. The addition of 10mol% mullite to HAP and TCP was effective for the improvement of mechanical property.