Fabrication of Hydroxyapatite Ceramics by Rapid Microwave Layer-by-Layer Sintering.

Using hydroxyapatite as an example, first results of research on a new additive method of manufacturing ceramic products are presented. The method consists of repeated sequential application of suspension layers with high content of powder material and their rapid 24 GHz microwave sintering. The stability of aqueous suspensions of hydroxyapatite powder with submicron particle size depending on the pH of the dispersion medium and dispersants was studied. Suspensions with a high value of the solid load mass and a fluidity sufficient to ensure the continuity of layers applied by the doctor blade method were obtained. By the method of layer-by-layer microwave sintering with a heating rate of up to 30°C/min and a maximum temperature of up to 1330°C, ceramic samples with a closed system of micron-sized pores and a density of up to 92% of the theoretical value were obtained. [ABSTRACT FROM AUTHOR]