粉末冶金Mg/TCP复合材料生理腐蚀行为研究

Study on Corrosion Performance in HBSS of Mg/TCP Fabricated through Powder Metallurgy

采用粉末冶金法制备出纯镁及不同磷酸三钙(TCP)含量的Mg/TCP复合材料,并将纯镁及Mg/TCP复合材料置于37℃的Hank’s平衡盐溶液(HBSS)中浸泡腐蚀及电化学分析,通过析氢速度、腐蚀失重、溶液pH值变化及腐蚀电流密度考察其生理腐蚀行为,利用X射线衍射(XRD)和扫描电镜(SEM)研究腐蚀产物及腐蚀形貌。结果表明,加入适量TCP,Mg/TCP复合材料耐蚀性能有所提高;当TCP含量为5%时,材料耐蚀性能最好。经模拟体液浸泡后,复合材料试样表面有羟基磷灰石(HA)的沉积,而纯镁试样表面则未检测到HA,说明Mg/TCP复合材料具有更好的骨诱导性。

Mg /TCP composites with different fraction of TGP were prepared through powder metallurgy and extrusion process.Through electrochemical test and immersion corrosion test,the corrosion properties of the composites in HBSS were studied.The topology and crystal structure of as-corroded samples were investigated by using SEM and XRD,respectively.It was shown that TCP increased corrosion resistance of the Mg / TCP composite.But the effect of TCP content on the corrosion resistance was non-linear.After immersed in SBF for 3d,HA was formed on the surface of the Mg / TCP composite but not on the surface of pure Mg.The HA deposition inhibited the corrosion of the composites to some extent,leading to the decrease of the corrosion.