Microwave assisted-in situ synthesis of porous titanium/calcium phosphate composites and their in聽vitro apatite-forming capability

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• 作者：Man-Tik Choy^a ; Chak-Yin Tang^a ; ^{mfcytang@polyu.edu.hk" class="auth_mail" title="E-mail the corresponding author} ; Ling Chen^a ; Wing-Cheung Law^a ; Chi-Pong Tsui^a ; William Weijia Lu^b
• 关键词：A. Metal&ndash ; matrix composites (MMCs) ; B. Microstructures ; E. Powder processing ; E. Sintering
• 刊名：Composites Part B: Engineering
• 出版年：2015
• 出版时间：15 December 2015
• 年：2015
• 卷：83
• 期：Complete
• 页码：50-57
• 全文大小：2771 K

文摘

Microwave irradiation has been proven to be an effective heating source in synthetic chemistry, and can accelerate the reaction rate, provide more uniform heating and help in developing better synthetic routes for the fabrication of bone-grafting implant materials. In this study, a new technique, which comprises microwave heating and powder metallurgy for in situ synthesis of Ti/CaP composites by using Ti powders, calcium carbonate (CaCO₃) powders and dicalcium phosphate dihydrate (CaHPO₄·2H₂O) powders, has been developed. Three different compositions of Ti:CaCO₃:CaHPO₄·2H₂O powdered mixture were employed to investigate the effect of the starting atomic ratio of the CaCO₃ to CaHPO₄·2H₂O on the phase, microstructural formation and compressive properties of the microwave synthesized composites. When the starting atomic ratio reaches 1.67, composites containing mainly alpha-titanium (伪-Ti), hydroxyapatite (HA), beta-tricalcium phosphate (尾-TCP) and calcium titanate (CaTiO₃) with porosity of 26%, pore size up to 152 渭m, compressive strength of 212 MPa and compressive modulus of 12 GPa were formed. The in vitro apatite-forming capability of the composite was evaluated by immersing the composite into a simulated body fluid (SBF) for up to 14 days. The results showed that biodissolution occurred, followed by apatite precipitation after immersion in the SBF, suggesting that the composites are suitable for bone implant applications as apatite is an essential intermediate layer for bone cells attachment. The quantity and size of the apatite globules increased over the immersion time. After 14 days of immersion, the composite surface was fully covered by an apatite layer with a Ca/P atomic ratio approximately of 1.68, which is similar to the bone-like apatite appearing in human hard tissue. The results suggested that the microwave assisted-in situ synthesis technique can be used as an alternative to traditional powder metallurgy for the fabrication of Ti/CaP biocomposites.