Al³⁺ Doped Nano-Hydroxyapatites and their Sintering Characteristics

Abstract

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°C and 1300°C. Second phases were formed after increasing the Al³⁺ content from 2.5% to 7.5% in HA and increasing the sintering temperature from 1100°C to 1300°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°C to 1300°C, densification was improved, which was verified by SEM micrographs. Al³⁺ addition resulted in smaller grain size after the sintering at 1300°C.