Effect of fluoride additive on the mechanical properties of hydroxyapatite/alumina composites

Abstract The effect of fluoride additives on the mechanical properties of hydroxyapatite/alumina composites was investigated. When MgF 2 (5 vol%) was added to hydroxyapatite/alumina composites, the decomposition of hydroxyapatite was suppressed due to the substitution of F − for OH − in the crystal structure. Comparing two additives, such as MgF 2 and CaF 2 , MgF 2 showed much more effective for the suppression of phase decomposition in the hydroxyapatite/alumina composites due to the enhanced substitution of F − for OH − . In the case of MgF 2 addition, a relatively high-mechanical properties (flexural strength: ∼170 MPa; Vickers hardness: ∼7 GPa) was obtained compared to MgF 2 -free composites.