| The research focuses on designing a novel biodegradable bioceramics which can be used as bone substitute. This kind of material can form pores in situ owing to the different degrading speed ofβ-TCP and HAP. The mechanical property of the new material is trying to be improved in different ways.β-tricalcium phosphate(β-TCP) is synthesized by wet precipitation. CaO-MgO-Na2O-P2O5 bioglass is designed and fabricated based on related data and phase graphs by melting method, which will be used as a sintering additive. The method to produce sphericalβ-TCP granules is based on liquids immiscibility and sol-gel effect. The diameter of the spheres centralizes between 0.6mm-0.8mm. The process is repeatable and its working conditions are confirmed.Column samples are prepared to represent the property diversification of the packed-sphere samples on different process factors, such as powder content, bioglass content and sintering temperature. The column samples produced under the conditions of powder content 0.625g/ml, bioglass content 15% and sintering temperature 1000°C have high density. The XRD research shows that the material contents solid solution Ca9MgNa(PO4)7 and a little of Ca2P2O7 phase. Packed-sphere samples are prepared and analyzed by measuring their density, mechanical property, and SEM photos. The diameter range is also found having great influences on it. The samples that the spheres centralized between 0.6mm-0.8mm have high compressive strength values of 27.6MPa.The composite is made by vacuum soaking packed-sphere samples in HAP sol. The property of composite samples has the same trend as before. The compressive strength values also reach 27.7MPa.The in vitro biodegradation ofβ-TCP/HAP composite samples in TRIS/HCl shows that the degradation speed of the material within bioglass is very closed to pureβ-TCP. So it can be concluded that the addition of bioglass improves the mechanical property of the new material and have no affections on its biodegrading speed. |
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