Preparation of HA-Bioglass-Al 2 O 3 Biological Composite

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.