Compaction of hydroxyapatite nanopowders by hydrostatic pressing

Resumo

In this work, we show how the degree of compaction upon pressing of two hydroxyapatite nanopowders, whose average particle sizes are 18 and 65 nm, influences the density and strength of ceramics on their basis. The density and the flexural strength are found to be higher for a ceramic based on the powder with the particle size of 65 nm at the same density of precursors. The flexural strength of ceramic on its base was 20–25% higher than for ceramic of a powder with the average particle size of 18 nm at the identical density of precursors. The additional hydrostatic pressing increases the densities of specimens by 10–12%. The final hydroxyapatite ceramics are characterized by a fairly high bending density of 170 MPa and homogeneous structure with the average crystallite size of 0.4–0.6 μm.