TITLE:
Sintering and Mechanical Properties of Magnesium and Fluorine Co-Substituted Hydroxyapatites
AUTHORS:
Samia Nsar, Amel Hassine, Khaled Bouzouita
KEYWORDS:
Hydroxyapatite; Magnesium, Fluorine; Sintering; Mechanical Properties
JOURNAL NAME:
Journal of Biomaterials and Nanobiotechnology,
Vol.4 No.1,
January
17,
2013
ABSTRACT: Biological apatites contain several elements as traces. In this work, Magnesium and fluorine co-substituted hydroxyapatites with the general formula Ca9Mg(PO4)6(OH)2-yFy, where y = 0, 0.5, 1, 1.5 and 2 were synthesized by the hydrothermal method. After calcination at 500℃, the samples were pressureless sintered between 950℃ and 1250℃. The substitution of F- for OH- had a strong influence on the densification behavior and mechanical properties of the materials. Below 1200℃, the density steeply decreased for y = 0.5 sample. XRD analysis revealed that compared to hydroxylfluorapatite containing no magnesium, the substituted hydroxyfluorapatites decomposed, and the nature of the decomposition products is tightly dependent on the fluorine content. The hardness, elastic modulus and fracture toughness of these materials were investigated by Vickers’s hardness testing. The highest values were 622 ± 4 GPa, 181 ± 1 GPa and 1.85 ± 0.06 MPa.m1/2, respectively.