Al3+ doped nano-hydroxyapatites and their sintering characteristics

Pure and Al3+ doped nano-hydroxyapatites (HA) were synthesized by a precipitation method to investigate their densification and thermal stability after the air sintering at 1100 degrees C and 1300 degrees C. Second phases were formed after increasing the All, content from 2.5% to 7.5% in HA and increasing the sintering temperature from 1100 degrees C to 1300 degrees C. Al3+ addition into HA resulted in change in the hexagonal lattice parameters from the pure HA. When the sintering temperature was increased from 1100 degrees C to 1300 degrees C, densification was improved, which was verified by SEM micrographs. Al3+ addition resulted in smaller grain size after the sintering at 1300 degrees C.