X-ray investigation of the powders of tricalcium phosphate exposed to processing in planetary mill

Abstract

Using the Rietveld X-ray method, the powders of tricalcium phosphate (α-TCP) were analyzed after their treatment in a planetary mill in various liquids (butanol, isobutyl alcohol, acetone, and ethanol). No features of the decomposition of α-TCP were detected and the parameters of its atomic-crystal structure did not change significantly. The reduction of the coherent scattering domains (DS) (d ~ 800 A) was a major contribution to X-ray line broadening, while its value did not depend on physical properties of liquids. Particles dispersed during their processing in the mill owing to their brittle destruction by chipping. After 60 min of powder processing in butanol, mean particle size decreased by a factor of five (from 9.7 to 2 μm). After annealing at 1300°C, the fluorohydroxyapatite phase was detected in powders, whose formation was assisted by the impurities from fluorine-containing structural elements of the mill.