Microstructure and corrosion behavior of coated AZ91 alloy by microarc oxidation for biomedical application
Microstructure and corrosion behavior of coated AZ91 alloy by microarc oxidation for biomedical application
复制标题
生物医学应用微弧氧化涂层 AZ91 合金的显微组织和腐蚀行为。
DOI：
10.1016/j.apsusc.2009.06.116
复制
发表时间：
2009-08-30
影响因子：
6.7
通讯作者：
Ouyang, J. H.
中科院分区：
文献类型：
--
作者：
Wang, Y. M.;Wang, F. H.;Ouyang, J. H.
镁及其合金是目前公认的具有生物降解潜力的植入材料，但由于其在体内环境中的加速腐蚀，导致植入体在完全修复前丧失力学完整性而失效。采用微弧氧化技术在镁合金表面制备了致密的氧化膜。对涂层试样的微观结构、成分及在模拟体液中的降解行为进行了评价。结果表明，在碱性硅酸盐电解液中加入TiO2溶胶，在以MgO和Mg2SiO4为主要成分的镀层中引入了少量的TiO2。随着二氧化钛溶胶的浓度从0增加到10体积%，电化学测试表明，微弧氧化后镁基体的E（corr）正移约300，与500 mV相近，i（corr）降低100倍以上。而在含5%和10%（体积分数）TiO2的电解液中，与未改性的涂层相比，二氧化钛溶胶的耐腐蚀性越来越差，这可能是由于二氧化钛溶胶的加入导致涂层中非晶态成分的增加。在模拟体液中的长期浸泡试验与电化学试验结果一致，涂层镁合金明显减缓了生物降解速率，同时5vol. %和10vol. %改性涂层的生物降解损伤趋势增加二氧化钛溶胶(C)2009年爱思唯尔B。V.保留所有权利。
Magnesium and its alloy currently are considered as the potential biodegradable implant materials, while the accelerated corrosion rate in intro environment leads to implant failure by losing the mechanical integrity before complete restoration. Dense oxide coatings formed in alkaline silicate electrolyte with and without titania sol addition were fabricated on magnesium alloy using microarc oxidation process. The microstructure, composition and degradation behavior in simulated body fluid (SBF) of the coated specimens were evaluated. It reveals that a small amount of TiO(2) is introduced into the as-deposited coating mainly composed of MgO and Mg(2)SiO(4) by the addition of titania sol into based alkaline silicate electrolytic bath. With increasing concentration of titania sol from 0 to 10 vol.%, the coating thickness decreases from 22 to 18 mm. Electrochemical tests show that the E(corr) of Mg substrate positively shifted about 300 similar to 500 mV and i(corr) lowers more than 100 times after microarc oxidation. However, the TiO(2) modified coatings formed in electrolyte containing 5 and 10 vol.% titania sol indicate an increasing worse corrosion resistance compared with that of the unmodified coating, which is possibly attributed to the increasing amorphous components caused by TiO(2) involvement. The long term immersing test in SBF is consistent with the electrochemical test, with the coated Mg alloy obviously slowing down the biodegradation rate, meanwhile accompanied by the increasing damage trends in the coatings modified by 5 and 10 vol.% titania sol. (C) 2009 Elsevier B. V. All rights reserved.