Preparation of HA-Bioglass-Al₂O₃ Biological Composite

Abstract

HA-Bioglass-Al₂O₃ composites were successfully fabricated by mixing HA, synthesized by wet chemical method between precursor materials H₃PO₄ and Ca(OH)₂, with 25 wt% Al₂O₃ and different content of bioglass (5, 25, 45, and 65 wt%), respectively, with a mole fraction of 53.9%SiO₂, 22.6%Na₂O, 21.8%CaO, and 1.7 wt%P₂O₅, sintered in air at relative low temperature (750–950°C) for 2 h. It can be seen that when the content of bioglass is above 45 wt% in the composite, the decomposition of HA to β-TCP, considerable thermal reaction and phase degradation are suppressed, and the main phases in this case are Al₂O₃, HA, and a small amount of DCP (CaHPO₄) and β-TCP, which almost have the same chemical composition, forming ternary-glass phase, and have better bioactive than pure HA. It can also be found that the exposed HA particles increase with the increasing of the bioglass content in the mixture. A large number of HA particles stacked together are subjected to form roughened surface, wherein microcracks, voids, and pores are observed, suggesting that pressureless-sintering is not the best way for densification of HA-Bioglass-Al₂O₃ composite.

Keywords:

• Alumina
• Crystallization
• Hydroxyapatite
• Microstructure

ACKNOWLEDGMENTS

This work was supported by the Science and Technology Plan of Weiyang District, Xi'an City (201204), Xianyang City Science and Technology Bureau (2011K09-23), Department of Education of Shaanxi Province (12JK0468), and Yulin City Science and Technology Bureau.